Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Nitrogen Deposition Maintains a Positive Effect on Terrestrial Carbon Sequestration in the 21st Century Despite Growing Phosphorus Limitation at Regional Scales
    Fleischer, Katrin ; Dolman, A.J. ; Molen, Michiel K. van der; Rebel, Karin T. ; Erisman, Jan Willem ; Wassen, Martin J. ; Pak, Bernard ; Lu, Xingjie ; Rammig, Anja ; Wang, Ying Ping - \ 2019
    Global Biogeochemical Cycles 33 (2019)6. - ISSN 0886-6236 - p. 810 - 824.
    carbon sequestration - land carbon sink - nitrogen deposition - nitrogen fixation - phosphorus limitation - terrestrial ecosystems

    Nitrogen (N) and phosphorus (P) are two dominant nutrients regulating the productivity of most terrestrial ecosystems. The growing imbalance of anthropogenic N and P inputs into the future is estimated to exacerbate P limitation on land and limit the land carbon (C) sink, so that we hypothesized that P limitation will increasingly reduce C sequestered per unit N deposited into the future. Using a global land surface model (CABLE), we simulated the effects of increased N deposition with and without P limitation on land C uptake and the fate of deposited N on land from 1901 to 2100. Contrary to our hypothesis, we found that N deposition continued to induce land C sequestration into the future, contributing to 15% of future C sequestration as opposed to 6% over the historical period. P limitation reduced the future land C uptake per unit N deposited only moderately at the global scale but P limitation increasingly caused N deposition to have net negative effects on the land C balance in the temperate zone. P limitation further increased the fraction of deposited N that is lost via leaching to aquatic ecosystems, globally from 38.5% over the historical period to 53% into the future, and up to 75% in tropical ecosystems. Our results suggest continued N demand for plant productivity but also indicate growing adverse N deposition effects in the future biosphere, not fully accounted for in global models, emphasizing the urgent need to elaborate on model representations of N and P dynamics.

    The steering role of plant-soil interactions in natural community dynamics and nature restoration
    Wubs, Engel Reinder Jasper - \ 2017
    Wageningen University. Promotor(en): W.H. Putten; T.M. Bezemer. - Wageningen : Wageningen University - ISBN 9789463434447 - 242
    soil plant relationships - soil - plants - ecological restoration - terrestrial ecosystems - soil inoculation - plant communities - soil ecology - bodem-plant relaties - bodem - planten - ecologisch herstel - terrestrische ecosystemen - bodeminoculatie - plantengemeenschappen - bodemecologie

    Biodiversity is declining worldwide and many ecosystems have been degraded due to human actions. There have been many attempts to restore degraded ecosystems, but restoration success varies. Past human management has left important abiotic and biotic legacies and active intervention is needed to overcome these legacies. Legacy effects include altered abiotic conditions and limited availability of appropriate seeds. However, plants also have many interactions with the myriad organisms that inhabit the soil. Soil biota include e.g. bacteria, fungi, nematodes, collembolan, and mites. Restoring plant-soil interactions may be key to successful ecological restoration, because studies on natural succession in ecosystems show that both plant and soil communities develop in concert. In addition, late-successional soil communities promote the performance of late-succession plant species that are often the target species for restoration. The aims of my thesis were to 1) test whether inoculation of living soil can improve restoration of species-rich grasslands and dry heathlands, and 2) understand how plant-soil interactions affect plant composition and diversity.

    In a large-scale field experiment, called “Reijerscamp-experiment”, I tested the potential of soil inoculation to speed up ecosystem restoration. On a former arable field large areas of on average 0.5 ha were inoculated with a thin layer of <1 cm living soil, which was taken either from a mid-succession grassland or a dry-heathland. After six years I monitored the species composition of the vegetation and the soil community. I found that both types of inoculum had substantially altered the community composition of both soil and vegetation. Moreover, the soil inocula had caused a shift in the direction of the respective donor communities. In a parallel mesocosm experiment I repeated the experiment while sowing a standardized species-rich seed mixture to ensure that seed availability was the same in all treatments. Also in this case the sown plant community developed towards the respective communities found in the donor sites. Consequently the soil community is, at least in part, able to steer plant community composition in the field.

    I also tested how mixtures of inocula from different donor systems affect restoration success. In a greenhouse experiment I made replacement series of soil inocula sourced from arable fields, mid-succession grasslands and dry heathlands and monitored the responses of target and ruderal plant species. The target species all responded positively to higher proportions of heathland material in the inoculum, while the responses of the ruderal species were variable. Interestingly, a 50:50 mixture of arable and heathland inoculum strongly reduced the growth of the ruderal species. Soil inoculation may be considered as a way of microbiome engineering, which is a newly emerging field mainly used to improve human health and agricultural production. My results show that conceptually similar techniques can be applied to improve inocula for the restoration of ecological communities.

    In a second field experiment I tested the long-term consequences of soil inoculation with and without sowing mid-successional plant species for plant and soil community composition. I found that sowing strongly altered plant community composition for over two decades. Soil inoculation, on the other hand, substantially altered the composition of the soil nematode community and that these effects persisted for at least 15 years. However, in contrast to the Reijerscamp experiment, the effect of soil inoculation on vegetation composition was transient. I propose that in this case the presence of an intact arable top soil, as well as perhaps a too minimal difference between the composition of the donor and recipient soil communities may have limited the impact of the soil inocula.

    In general, the restoration of plant cover and a number of common (‘matrix’) plant species can be achieved using standard approaches, e.g. reducing site fertility and providing seed material, but creating conditions that allow for coexistence of both locally dominant and rare subordinate species proves much more elusive. Fundamental knowledge on how biodiversity is regulated is needed to restore diverse plant communities including the rare species. Testing plant-soil feedback provides a way to directly study the net consequences of the myriad interactions between plants and soil biota for plant performance and community composition. However, while both plants and soil communities are strongly heterogeneous in space and time, spatiotemporally explicit tests of plant-soil feedback are rare.

    In a greenhouse experiment I studied how spatial heterogeneity in plant-soil feedbacks influence plant communities. I found that when multiple species conditioned the soil, plant performance was reduced compared to mono-specific soil conditioning. This reduction in competitive ability led to a higher plant diversity in the experimental communities. The plant responses were not related to differences in abiotic conditions, but soil conditioning induced clear changes in fungal community composition. Recent meta-analyses and experiments have shown that spatial heterogeneity in abiotic conditions only promotes plant diversity when the grain of the heterogeneity is larger than the size of individual plants. When it is smaller, heterogeneity simply selects for those species that have the highest root plasticity and this leads to lower plant diversity. Together, these results suggest that spatial heterogeneity in abiotic conditions only promotes plant beta diversity, while interaction with the soil community, primarily soil-borne antagonists, maintains plant alpha diversity.

    Finally, I used repeated soil conditioning by conspecific and heterospecific species to show that soil feedbacks may carry over across soil conditioning periods. In contrast to what is commonly assumed my data show that heterospecific soil-conditioning can result in equally negative PSF as repeated conspecific soil-conditioning and repeated conspecific soil-conditioning does not always lead to stronger negative feedback. Instead, the particular sequence of plant species that successively condition the soil strongly determines the sign and magnitude of PSF. These results highlight the need to incorporate sequential soil-conditioning in models of plant communities and effective crop-rotations.

    In conclusion, plant-soil interactions are a key aspect in the natural dynamics of plant communities and can be used to improve restoration of semi-natural ecosystems. Abiotic conditions and dispersal ability determine which species may occur in a given site. However, at small spatial scales plant-soil feedbacks and particularly interactions with soil borne antagonists can enhance plant species diversity. Manipulation of the soil community, through inoculation of soil from well-developed donor sites can speed up natural succession and even steer its direction in the field. However, soil inoculation success will not be universal and depends on the match in abiotic conditions of donor and recipient sites, as well as the community composition of the inoculum and the resident communities. Future studies are needed to test the success of introducing soil communities across environmental gradients.

    Global carbon budget 2014
    Quéré, C. Le; Peters, W. ; Moriarty, R. ; Friedlingstein, P. - \ 2015
    Earth System Science Data 7 (2015)1. - ISSN 1866-3508 - p. 47 - 85.
    land-use change - environment simulator jules - co2 flux variability - mixed-layer scheme - earth system model - atmospheric co2 - dioxide emissions - interannual variability - terrestrial ecosystems - international-trade
    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover-change (some including nitrogen–carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1s, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004–2013), EFF was 8.9 ± 0.4 GtC yr-1, ELUC 0.9 ± 0.5 GtC yr-1, GATM 4.3 ± 0.1 GtC yr-1, SOCEAN 2.6 ± 0.5 GtC yr-1, and SLAND 2.9 ± 0.8 GtC yr-1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr-1, 2.3% above 2012, continuing the growth trend in these emissions, ELUC was 0.9 ± 0.5 GtC yr-1, GATM was 5.4 ± 0.2 GtC yr-1, SOCEAN was 2.9 ± 0.5 GtC yr-1, and SLAND was 2.5 ± 0.9 GtC yr-1. GATM was high in 2013, reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004–2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3–3.5%) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO2 yr-1), 65% above emissions in 1990, based on projections of world gross domestic product and recent changes in the carbon intensity of the global economy. From this projection of EFF and assumed constant ELUC for 2014, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870–2014, about 75% from EFF and 25% from ELUC. This paper documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this living data set (Le Quéré et al., 2013, 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis
    Nitrogen : too much of a vital resource : Science Brief
    Erisman, J.W. ; Galloway, J.N. ; Dise, N.B. ; Sutton, M.A. ; Bleeker, A. ; Grizzetti, B. ; Leach, A.M. ; Vries, W. de - \ 2015
    Zeist, The Netherlands : WWF Netherlands (WWF science brief NL ) - ISBN 9789074595223 - 27
    stikstofkringloop - waterverontreiniging - eutrofiëring - emissiereductie - broeikasgassen - terrestrische ecosystemen - wetenschappelijk onderzoek - milieubeleid - nitrogen cycle - water pollution - eutrophication - emission reduction - greenhouse gases - terrestrial ecosystems - scientific research - environmental policy
    It is now clear that the nitrogen problem is one of the most pressing environmental issues that we face. But in spite of the enormity of our influence on the N cycle and consequent implications for the environment and for human well-being, there is surprisingly little attention paid to the issue. While biodiversity loss and climate change have spawned huge budgets to create national and multidisciplinary programs, global organizations, political and media attention, the N challenge remains much less apparent in our thinking and actions. This is because we are educated with the important role that N plays with regard to food security. This paper aims to contribute to the understanding of the N challenge, and to provide options for decreasing the negative impacts of excess N.
    Growth adjustments of conifers to drought and to century-long irrigation
    Feichtinger, L.M. ; Eilmann, B. ; Buchmann, N. ; Rigling, A. - \ 2014
    Forest Ecology and Management 334 (2014). - ISSN 0378-1127 - p. 96 - 105.
    scots pine stands - water availability - climate-change - terrestrial ecosystems - wood formation - radial growth - tree-growth - ring width - sylvestris - mortality
    Our knowledge on tree responses to drought is mainly based on short-term manipulation experiments which do not capture any possible long-term adjustments in this response. Therefore, historical water channels in inner-Alpine dry valleys were used as century-long irrigation experiments to investigate adjustments in tree growth to contrasting water supply. This involved quantifying the tree-ring growth of irrigated and non-irrigated (control) Scots pine (Pinus sylvestris L.) in Valais (Switzerland), as well as European larch (Larix decidua Mill.) and black pine (Pinus nigra Arnold) in Vinschgau (Italy). Furthermore, the adjustments in radial growth of Scots pine and European larch to an abrupt stop in irrigation were analyzed. Irrigation promoted the radial growth of all tree species investigated compared to the control: (1) directly through increased soil water availability, and (2) indirectly through increased soil nutrients and humus contents in the irrigated plots. Irrigation led to a full elimination of growth responses to climate for European larch and black pine, but not for Scots pine, which might become more sensitive to drought with increasing tree size in Valais. For the control trees, the response of the latewood increment to water availability in July/August has decreased in recent decades for all species, but increased in May for Scots pine only. The sudden irrigation stop caused a drop in radial growth to a lower level for Scots pine or similar level for larch compared to the control for up to ten years. However, both tree species were then able to adjust to the new conditions and subsequently grew with similar (Scots pine) or even higher growth rates(larch) than the control. To estimate the impact of climate change on future forest development, the duration of manipulation experiments should be on longer time scales in order to capture adjustment processes and feedback mechanisms of forest ecosystems. (C) 2014 Published by Elsevier B.V.
    Short and long-term impacts of nitrogen deposition on carbon sequestration by forest ecosystems
    Vries, W. de; Du, E. ; Butterbach-Bahl, K. - \ 2014
    Current Opinion in Environmental Sustainability 9-10 (2014). - ISSN 1877-3435 - p. 90 - 104.
    dissolved inorganic nitrogen - warm-temperate forest - elevated n inputs - terrestrial ecosystems - european forests - climate-change - boreal forest - anthropogenic nitrogen - microbial biomass - tropical forests
    The carbon to nitrogen response of forest ecosystems depends on the possible occurrence of nitrogen limitation versus possible co-limitations by other drivers, such as low temperature or availability of phosphorus. A combination of nitrogen retention estimates and stoichiometric scaling is used to illustrate the most likely carbon–nitrogen responses for needle-leaved and broadleaved forests to atmospheric nitrogen deposition. Results are evaluated against field observations and nitrogen addition experiments. The likely change in carbon to nitrogen response with nitrogen deposition level is hypothesized, distinguishing three threshold values that mark the forest carbon responses. We estimated that at global scale nitrogen deposition currently increases the forest carbon sink by 276–448 Tg C yr1, with approximately 60% retained in tree wood and 40% in soil. Furthermore, the long-term carbon response to nitrogen, accounting for nitrogen saturation over time is hypothesized. In this context, the role of global scale coupled carbon–nitrogen models is also evaluated in view of current knowledge affecting carbon–nitrogen responses, including interactions with other drivers.
    Ecologie van bodemmicro-organismen: de basis voor een gezonde bodem
    Boer, W. de - \ 2014
    Gewasbescherming 45 (2014)1. - ISSN 0166-6495 - p. 4 - 6.
    bodemecologie - terrestrische ecosystemen - microbiologie - openbare redes - gewasbescherming - bodemweerbaarheid - bodembiologie - soil ecology - terrestrial ecosystems - microbiology - public speeches - plant protection - soil suppressiveness - soil biology
    Dit is de titel van de inaugurele rede die op 14 februari 2013 heb gehouden in de aula van Wageningen University bij de aanvaarding van het ambt als buitengewoon hoogleraar Microbiële Bodemecologie. Onlangs is de gedrukte versie verschenen. In de rede wordt ingegaan op het belang van interacties tussen bodemmicro-organismen voor het functioneren van het bodemecosysteem en met name op de natuurlijk regulerende werking die microbiële interacties kunnen hebben op ziekteverwekkers in de bodem.
    Suitability of faeces and tissue samples as a basis for non-invasive sampling for African swine fever in wild boar
    Carvalho Ferreira, H.C. de; Weesendorp, E. ; Quak, S. ; Stegeman, J.A. ; Loeffen, W.L.A. - \ 2014
    Veterinary Microbiology 172 (2014)3-4. - ISSN 0378-1135 - p. 449 - 454.
    terrestrial ecosystems - sus-scrofa - virus - size - europe - pigs
    A challenging aspect of ASFV control in wild boar populations is the design and implementation of effective surveillance and monitoring programmes, both for early warning, and to determine the ongoing epidemiological situation in an infected population. Testing blood samples requires invasive sampling strategies like hunting or capture of wild boar. Besides being biased towards healthy animals, such strategies are also linked to further spread of the virus. Non-invasive sampling strategies would increase the reliability of surveillance of ASFV in wild boar populations, without the negative side effects. This study evaluates the potential of faeces and tissue samples as a basis for non-invasive sampling strategies for ASFV in wild boar. In the acute phase (0–21 days after infection), in comparison with virus detection in blood, virus can be detected in faeces 50–80% of the time. This percentage decreases to below 10% for the subacute/chronic phase. ASFV DNA is quite stable in faeces. Half-lives range from more than 2 years at temperature up to 12 °C, to roughly 15 days at temperatures of 30 °C. In tissue samples, stored at 20 °C, half-lives mostly range from 1.7 to 7.4 days. The sample of preference is the spleen, where the highest titres and highest half-life of ASFV DNA are observed. The level and duration of excretion of ASFV in the faeces, combined with the stability of the DNA, suggest that sampling of faeces could be the basis for a non-invasive sampling strategy to monitor ASFV in wild boar.
    How light competition between plants affects their response to climate change
    Loon, M.P. van; Schieving, F. ; Rietkerk, M. ; Dekker, S.C. ; Sterck, F.J. ; Anten, N.P.R. - \ 2014
    New Phytologist 203 (2014)4. - ISSN 0028-646X - p. 1253 - 1265.
    leaf-area index - co2 enrichment face - canopy carbon gain - elevated co2 - atmospheric co2 - stomatal conductance - terrestrial ecosystems - nitrogen availability - global change - gas-exchange
    How plants respond to climate change is of major concern, as plants will strongly impact future ecosystem functioning, food production and climate. Here, we investigated how vegetation structure and functioning may be influenced by predicted increases in annual temperatures and atmospheric CO2 concentration, and modeled the extent to which local plant–plant interactions may modify these effects. A canopy model was developed, which calculates photosynthesis as a function of light, nitrogen, temperature, CO2 and water availability, and considers different degrees of light competition between neighboring plants through canopy mixing; soybean (Glycine max) was used as a reference system. The model predicts increased net photosynthesis and reduced stomatal conductance and transpiration under atmospheric CO2 increase. When CO2 elevation is combined with warming, photosynthesis is increased more, but transpiration is reduced less. Intriguingly, when competition is considered, the optimal response shifts to producing larger leaf areas, but with lower stomatal conductance and associated vegetation transpiration than when competition is not considered. Furthermore, only when competition is considered are the predicted effects of elevated CO2 on leaf area index (LAI) well within the range of observed effects obtained by Free air CO2 enrichment (FACE) experiments. Together, our results illustrate how competition between plants may modify vegetation responses to climate change.
    On the variation of regional CO2 exchange over temperate and boreal North America
    Zhang, X. ; Gurney, K.R. ; Peylin, P. ; Chevallier, F. ; Law, R.M. ; Patra, P.K. ; Rayner, P.J. ; Roedenbeck, C. ; Krol, M.C. - \ 2013
    Global Biogeochemical Cycles 27 (2013)4. - ISSN 0886-6236 - p. 991 - 1000.
    atmospheric carbon-dioxide - terrestrial ecosystems - united-states - interannual variability - climate - forest - trends - drought - fluxes - land
    Inverse-estimated net carbon exchange time series spanning two decades for six North American regions are analyzed to examine long-term trends and relationships to temperature and precipitation variations. Results reveal intensification of carbon uptake in eastern boreal North America (0.1 PgC/decade) and the Midwest United States (0.08 PgC/decade). Seasonal cross-correlation analysis shows a significant relationship between net carbon exchange and temperature/precipitation anomalies during the western United States growing season with warmer, dryer conditions leading reduced carbon uptake. This relationship is consistent with global change-type drought dynamics which drive increased vegetation mortality, increases in dry woody material, and increased wildfire occurrence. This finding supports the contention that future climate change may increase carbon loss in this region. Similarly, higher temperatures and reduced precipitation are accompanied by decreased net carbon uptake in the Midwestern United States toward the end of the growing season. Additionally, intensified net carbon uptake during the eastern boreal North America growing season is led by increased precipitation anomalies in the previous year, suggesting the influence of climate memory carried by regional snowmelt water. The two regions of boreal North America exhibit opposing seasonal carbon-temperature relationships with the eastern half experiencing a net carbon loss with near coincident increases in temperature and the western half showing increased net carbon uptake. The carbon response in the boreal west region lags the temperature anomalies by roughly 6months. This opposing carbon-temperature relationship in boreal North America may be a combination of different dominant vegetation types, the amount and timing of snowfall, and temperature anomaly differences across boreal North America.
    Differential Effects of Oxidised and Reduced Nitrogen on Vegetation and Soil Chemistry of Species-Rich Acidic Grasslands
    Dorland, E. ; Stevens, C.J. ; Gaudnik, C. ; Corcket, E. ; Rotthier, S.L.F. ; Wotherspoon, K. ; Jokerud, M. ; Vandvik, V. ; Soons, M.B. ; Hefting, M.M. ; Aarrestad, P.A. ; Alard, D. ; Diekmann, M. ; Dupre, C. ; Dise, N.B. ; Gowing, D.J.G. ; Bobbink, R. - \ 2013
    Water Air and Soil Pollution 224 (2013)9. - ISSN 0049-6979
    biological nitrification inhibition - terrestrial ecosystems - seminatural grasslands - heathland vegetation - deposition - plant - acidification - biodiversity - diversity - eutrophication
    Emissions and deposition of ammonia and nitrogen oxides have strongly increased since the 1950s. This has led to significant changes in the nitrogen (N) cycle, vegetation composition and plant diversity in many ecosystems of high conservation value in Europe. As a consequence of different regional pollution levels and of the increased importance of reduced N in the near future, determining the effect of different forms of N is an important task for understanding the consequences of atmospheric N inputs. We have initiated three replicated N addition experiments in species-rich, acidic grasslands spanning a climatic gradient in the Atlantic biogeographic region of Europe in Norway, Wales and France at sites with low levels of pollution. N was added in two doses (0 and 70 kg N ha(-1) year(-1) above background) and in three forms (oxidised N, reduced N and a 50-50 combination). After 2.5 years of N additions, the effects of these treatments on plant biomass, plant nutritional status, soil pH and soil nutrient availability were determined. Impacts of the N additions were observed within the 2.5-year research period. In some cases, the first signs of differential effects of N form could also be demonstrated. In the French site, for example, grass biomass was significantly increased by the oxidised N treatments but decreased by the reduced N treatments. In the Norwegian site, the reduced N treatments significantly reduced soil pH, whereas oxidised N did not. Effects on nutrient availability were also observed. These experiments will be continued to elucidate the longer term impacts of N deposition on these grasslands.
    Fauna in het rivierengebied. Knelpunten en mogelijkheden voor herstel van terrestrische en amfibische fauna
    Lange, H.J. de; Maas, G. ; Makaske, A. ; Nijssen, M. ; Noordijk, J. ; Rooij, S. van; Vos, C.C. - \ 2013
    Driebergen : Bosschap (Rapport / [DKI] nr. 2013/OBN175-RI) - 130
    fauna - amphibia - terrestrische ecosystemen - habitats - rivierengebied - natura 2000 - hoogwaterbeheersing - uiterwaarden - fauna - amphibia - terrestrial ecosystems - habitats - rivierengebied - natura 2000 - flood control - river forelands
    In het kader van Natura 2000 worden in Europees perspectief zeldzame soorten en zeldzame vegetatietypen in Nederland beschermd. In deze studie gaat het om habitattypen die niet zonder rivierinvloed kunnen voorkomen: “Beken en rivieren met waterplanten” (H3260), “Slikkige rivieroevers” (H3270), “Stroomdalgraslanden” (H6120), “Alluviale bossen” (H91E0), en “Droge hardhoutooibossen” (H91F0). Deze habitattypen, waarin gradiënten in verstoringsdynamiek, bodemstructuur, nutriëntenrijkdom en (bodem)-vochtgehalte worden beschreven, vormen tezamen een rijk mozaïek van habitats op relatief korte afstand van elkaar. Door klimaatverandering worden de verwachte extremen in waterafvoer in het rivierengebied groter. De manier waarop rivierverruiming dan wel dijkverzwaring wordt uitgevoerd is sterk bepalend voor de natuurwaarde en ecologisch rendement in het rivierengebied. Vanuit het natuurbeheer is er dan ook een grote behoefte aan adviezen voor inrichting en beheer om binnen de huidige randvoorwaarden van het Nederlandse rivierengebied de aanwezigheid van habitats, karakteristieke soorten en een hoge biodiversiteit te herstellen en behouden
    Ecological intensification: harnessing ecosystem services for food security
    Bommarco, R. ; Kleijn, D. ; Potts, S.G. - \ 2013
    Trends in Ecology and Evolution 28 (2013)4. - ISSN 0169-5347 - p. 230 - 238.
    bee species responses - biological-control - agricultural intensification - natural enemies - landscape scale - biodiversity conservation - terrestrial ecosystems - biotic interactions - soil biodiversity - plant-communities
    Rising demands for agricultural products will increase pressure to further intensify crop production, while negative environmental impacts have to be minimized. Ecological intensification entails the environmentally friendly replacement of anthropogenic inputs and/or enhancement of crop productivity, by including regulating and supporting ecosystem services management in agricultural practices. Effective ecological intensification requires an understanding of the relations between land use at different scales and the community composition of ecosystem service-providing organisms above and below ground, and the flow, stability, contribution to yield, and management costs of the multiple services delivered by these organisms. Research efforts and investments are particularly needed to reduce existing yield gaps by integrating context-appropriate bundles of ecosystem services into crop production systems
    Soil biotic legacy effects of extreme weather events influence plant invasiveness
    Meisner, A. ; Deyn, G.B. de; Boer, W. de; Putten, W.H. van der - \ 2013
    Proceedings of the National Academy of Sciences of the United States of America 110 (2013)24. - ISSN 0027-8424 - p. 9835 - 9838.
    drying-rewetting frequency - terrestrial ecosystems - microbial biomass - communities - feedback - productivity - invasibility - metaanalysis - disturbance - resilience
    Climate change is expected to increase future abiotic stresses on ecosystems through extreme weather events leading to more extreme drought and rainfall incidences [Jentsch A, et al. (2007) Front Ecol Environ 5(7):365–374]. These fluctuations in precipitation may affect soil biota, soil processes [Evans ST, Wallenstein MD (2012) Biogeochemistry 109:101–116], and the proportion of exotics in invaded plant communities [Jiménez MA, et al. (2011) Ecol Lett 14:1277–1235]. However, little is known about legacy effects in soil on the performance of exotics and natives in invaded plant communities. Here we report that drought and rainfall effects on soil processes and biota affect the performance of exotics and natives in plant communities. We performed two mesocosm experiments. In the first experiment, soil without plants was exposed to drought and/or rainfall, which affected soil N availability. Then the initial soil moisture conditions were restored, and a mixed community of co-occurring natives and exotics was planted and exposed to drought during growth. A single stress before or during growth decreased the biomass of natives, but did not affect exotics. A second drought stress during plant growth resetted the exotic advantage, whereas native biomass was not further reduced. In the second experiment, soil inoculation revealed that drought and/or rainfall influenced soil biotic legacies, which promoted exotics but suppressed natives. Our results demonstrate that extreme weather events can cause legacy effects in soil biota, promoting exotics and suppressing natives in invaded plant communities, depending on the type, frequency, and timing of extreme events.
    Shifts in global vegetation activity trends
    Jong, R. de; Verbesselt, J. ; Zeileis, A. ; Schaepman, M.E. - \ 2013
    Remote Sensing 5 (2013)3. - ISSN 2072-4292 - p. 1117 - 1133.
    net primary production - drought-induced reduction - image time-series - land-surface phenology - structural-change - satellite data - terrestrial ecosystems - ols residuals - ndvi data - avhrr
    Vegetation belongs to the components of the Earth surface, which are most extensively studied using historic and present satellite records. Recently, these records exceeded a 30-year time span composed of preprocessed fortnightly observations (1981–2011). The existence of monotonic changes and trend shifts present in such records has previously been demonstrated. However, information on timing and type of such trend shifts was lacking at global scale. In this work, we detected major shifts in vegetation activity trends and their associated type (either interruptions or reversals) and timing. It appeared that the biospheric trend shifts have, over time, increased in frequency, confirming recent findings of increased turnover rates in vegetated areas. Signs of greening-to-browning reversals around the millennium transition were found in many regions (Patagonia, the Sahel, northern Kazakhstan, among others), as well as negative interruptions—“setbacks”—in greening trends (southern Africa, India, Asia Minor, among others). A minority (26%) of all significant trends appeared monotonic
    A meta-database comparison from various European research networks dedicated to forests sites
    Danielewska, A. ; Clarke, N. ; Olejnik, J. ; Hansen, K. ; Vries, W. de - \ 2013
    iForest : Biogeosciences and Forestry 6 (2013). - ISSN 1971-7458 - p. 1 - 9.
    nitrogen deposition - terrestrial ecosystems - anthropogenic sources - air-pollutants - climate-change - united-states - heavy-metals - carbon - ozone - pollution
    Of a wide variety of international forest research and monitoring networks, several networks are dedicated to the effects of climate change on forests, while the effects of anthropogenic pollutants on forests have been a major area for both monitoring and research for decades. The large amounts of data already obtained within existing monitoring programmes and large-scale international projects can be used to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment, and a major challenge now is to evaluate and integrate the presently available databases. We present a meta-database with the main goal to highlight available data and integrate the information about research and monitoring of selected European Research and Monitoring Networks (ERMNs). Depending on the selected ERMNs, the list of variables and the measurement units differ widely in the databases. As a result, activities related to the identification, evaluation and integration of the presently available databases are important for the scientific community. Furthermore, and equally important, the recognition of current knowledge gaps and future needed research is made easier. This analysis suggests that: ground-level ozone is under-investigated, although it is one of the pollutants of greatest concern to forests; in addition to CO2, long-term other greenhouse gasses (GHG) flux measurements should be carried out; there is still a need of improving links between monitoring of atmospheric changes and impacts on forests; research-oriented manipulative experiments in the forests are missing.
    Soil and freshwater and marine sediment food webs: their structure and function
    Krumins, J.A. ; Oevelen, D. van; Bezemer, T.M. ; Deyn, G.B. de; Hol, W.H.G. ; Donk, E. van; Boer, W. de; Ruiter, P.C. de; Middelburg, J.J. ; Monroy, F. ; Soetaert, K. ; Thébault, E. ; Koppel, J. van de; Veen, J.A. van; Viketoft, M. ; Putten, W.H. van der - \ 2013
    Bioscience 63 (2013)1. - ISSN 0006-3568 - p. 35 - 42.
    global carbon-cycle - terrestrial ecosystems - real ecosystems - climate-change - biodiversity - stability - communities - limitation - patterns - sequestration
    The food webs of terrestrial soils and of freshwater and marine sediments depend on adjacent aboveground or pelagic ecosystems for organic matter input that provides nutrients and energy. There are important similarities in the flow of organic matter through these food webs and how this flow feeds back to primary production. In both soils and sediments, trophic interactions occur in a cycle in which consumers stimulate nutrient cycling such that mineralized resources are made available to the primary producers. However, aquatic sediments and terrestrial soils differ greatly in the connectivity between the production and the consumption of organic matter. Terrestrial soils and shallow aquatic sediments can receive organic matter within hours of photosynthesis when roots leak carbon, whereas deep oceanic sediments receive organic matter possibly months after carbon assimilation by phytoplankton. This comparison has implications for the capacity of soils and sediments to affect the global carbon balance.
    Simple additive effects are rare: a quantitative review of plant biomass and soil process responses to combined manipulations of CO2 and temperature
    Dieleman, W. ; Vicca, S. ; Dijkstra, F.A. ; Hoosbeek, M.R. - \ 2012
    Global Change Biology 18 (2012)9. - ISSN 1354-1013 - p. 2681 - 2693.
    elevated atmospheric co2 - global environmental-changes - carbon-cycle feedback - climate-change - terrestrial ecosystems - forest ecosystems - thermal-acclimation - heterotrophic respiration - semiarid grassland - nitrogen cycles
    In recent years, increased awareness of the potential interactions between rising atmospheric CO2 concentrations ([ CO2 ]) and temperature has illustrated the importance of multifactorial ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and [ CO2 ] manipulation, and compares it with those obtained in single factor [ CO2 ] and temperature manipulation experiments. Across all combined elevated [ CO2 ] and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the [ CO2 ]-only treatment than to those in the warming-only treatment. In contrast to warming-only experiments, both the combined and the [ CO2 ]-only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the [ CO2 ]-only treatment, possibly due to the warming-induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor [ CO2 ] treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated [ CO2 ] and warming, i.e. the response to the combined treatment was usually less-than-additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long-term) multifactor manipulation experiments. Because single factor CO2 responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
    Trend changes in global greening and browning: Contribution of short-term trends to longer-term change
    Jong, R. de; Verbesselt, J. ; Schaepman, M.E. ; Bruin, S. de - \ 2012
    Global Change Biology 18 (2012)2. - ISSN 1354-1013 - p. 642 - 655.
    net primary production - drought-induced reduction - structural-change models - image time-series - land-cover data - terrestrial ecosystems - photosynthetic trends - environmental-change - phenological change - vegetation indexes
    Field observations and time series of vegetation greenness data from satellites provide evidence of changes in terrestrial vegetation activity over the past decades for several regions in the world. Changes in vegetation greenness over time may consist of an alternating sequence of greening and/or browning periods. This study examined this effect using detection of trend changes in normalized difference vegetation index (NDVI) satellite data between 1982 and 2008. Time series of 648 fortnightly images were analyzed using a trend breaks analysis (BFAST) procedure. Both abrupt and gradual changes were detected in large parts of the world, especially in (semi-arid) shrubland and grassland biomes where abrupt greening was often followed by gradual browning. Many abrupt changes were found around large-scale natural influences like the Mt Pinatubo eruption in 1991 and the strong 1997/98 El Niño event. The net global figure – considered over the full length of the time series – showed greening since the 1980s. This is in line with previous studies, but the change rates for individual short-term segments were found to be up to five times higher. Temporal analysis indicated that the area with browning trends increased over time while the area with greening trends decreased. The Southern Hemisphere showed the strongest evidence of browning. Here, periods of gradual browning were generally longer than periods of gradual greening. Net greening was detected in all biomes, most conspicuously in croplands and least conspicuously in needleleaf forests. For 15% of the global land area, trends were found to change between greening and browning within the analysis period. This demonstrates the importance of accounting for trend changes when analyzing long-term NDVI time series.
    Climate change, aboveground-belowground interactions, and species range shifts
    Putten, W.H. van der - \ 2012
    Annual Review of Ecology, Evolution, and Systematics 43 (2012). - ISSN 1543-592X - p. 365 - 383.
    soil microbial communities - increased competitive ability - natural enemies - land-use - terrestrial ecosystems - evolutionary responses - litter decomposition - ecological responses - biotic interactions - plant diversity
    Changes in climate, land use, fire incidence, and ecological connections all may contribute to current species' range shifts. Species shift range individually, and not all species shift range at the same time and rate. This variation causes community reorganization in both the old and new ranges. In terrestrial ecosystems, range shifts alter aboveground-belowground interactions, influencing species abundance, community composition, ecosystem processes and services, and feedbacks within communities and ecosystems. Thus, range shifts may result in no-analog communities where foundation species and community genetics play unprecedented roles, possibly leading to novel ecosystems. Long-distance dispersal can enhance the disruption of aboveground-belowground interactions of plants, herbivores, pathogens, symbiotic mutualists, and decomposer organisms. These effects are most likely stronger for latitudinal than for altitudinal range shifts. Disrupted aboveground-belowground interactions may have influenced historical postglacial range shifts as well. Assisted migration without considering aboveground-belowground interactions could enhance risks of such range shift–induced invasions.
    An ecohydrological sketch of climate change impacts on water and natural ecosystems for the Netherlands: bridging the gap between science and society
    Witte, J.P.M. ; Runhaar, J. ; Ek, R. van; Hoek van der, D.C.J. ; Bartholomeus, R.P. ; Batelaan, O. ; Bodegom, P.M. van; Wassen, M.J. ; Zee, S.E.A.T.M. van der - \ 2012
    Hydrology and Earth System Sciences 16 (2012). - ISSN 1027-5606 - p. 3945 - 3957.
    ecohydrologie - ecosystemen - klimaatverandering - modellen - kaarten - ecohydrology - ecosystems - climatic change - models - maps - habitat distribution models - terrestrial ecosystems - vegetation - soil - balance - flow - co2 - precipitation - biodiversity - 20th-century
    For policy making and spatial planning, information is needed about the impacts of climate change on natural ecosystems. To provide this information, commonly hydrological and ecological models are used. We give arguments for our assessment that modelling only is insufficient for determining the impacts of climate changes on natural ecosystems at regional scales. Instead, we proposed a combination of hydrological simulations, a literature review and process-knowledge on climate-hydrology-vegetation interactions, to compile a sketch map that indicates climate change effects on a number of ecosystems in the Netherlands.Soon after a first version of our sketch map was published by a Dutch professional journal, copies appeared in policy documents, and also in a commercial and popular atlas of the Netherlands. Moreover, the map led to a question in the Dutch parliament about the sustainability of bog reserves under the future climate. Apparently, there was an urgent need for the information provided by the map.
    For policy making and spatial planning, information is needed about the impacts of climate change on natural ecosystems. To provide this information, commonly hydrological and ecological models are used. We give arguments for our assessment that modelling only is insufficient for determining the impacts of climate changes on natural ecosystems at regional scales. Instead, we proposed a combination of hydrological simulations, a literature review and process-knowledge on climate-hydrology-vegetation interactions, to compile a sketch map that indicates climate change effects on a number of ecosystems in the Netherlands. Soon after a first version of our sketch map was published by a Dutch professional journal, copies appeared in policy documents, and also in a commercial and popular atlas of the Netherlands. Moreover, the map led to a question in the Dutch parliament about the sustainability of bog reserves under the future climate. Apparently, there was an urgent need for the information provided by the map. The map shows that climate change will presumably have the largest influence on ecosystems in the Netherlands that depend on precipitation as the major water source, like heathlands, dry grasslands, rain-fed moorland pools and raised bogs. Also highly susceptible are fens in reserves surrounded by deeply drained polders, because such fens depend on the inlet of surface water, of which quality is likely to deteriorate upon climate change. While the map is indicative for directions of change, in view of the uncertainties of our study, no conclusions should be drawn that may have far-reaching consequences, such as giving up certain nature targets that might no longer be feasible in the future climate. Instead, we advise to anticipate the potential threats from climate change by taking a number of adaptation measures that enhance the robustness of nature reserves. To improve climate change projections on hydrology and ecosystems, future research should especially focus on feedbacks of vegetation on the water balance, on processes that directly influence plant performance and on the ecological effects of weather extremes.
    Doelrealisatiegraadmeter voor de ecologische hoofdstructuur
    Reijnen, M.J.S.M. ; Pouwels, R. ; Clement, J. ; Esbroek, M.L.P. van; Hinsberg, A. van; Kuipers, H. ; Eupen, M. van - \ 2012
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 305) - 82
    ecologische hoofdstructuur - natuurwaarde - flora - fauna - terrestrische ecosystemen - inventarisaties - ecological network - natural value - flora - fauna - terrestrial ecosystems - inventories
    Het Planbureau voor de Leefomgeving (PBL) geeft jaarlijkse trendcijfers van de natuurkwaliteit met de Natuurwaardegraadmeter 2.0. Om daarnaast te kunnen rapporteren waar binnen de Ecologische Hoofdstructuur (EHS) de beoogde kwaliteit wordt gerealiseerd is de ‘EHS Doelrealisatiegraadmeter’ (EDG) ontwikkeld. Voor de EDG worden vier stappen doorlopen: vervaardigen van een kaartbeeld van de natuurdoelen die nagestreefd worden, voor elke locatie beoordelen of een natuurdoel reeds voorkomt, vaststellen hoeveel planten, vlinders en vogels actueel voorkomen, en vergelijken van deze hoeveelheid met een specifieke norm voor het betreffende natuurdoel. Het eindresultaat laat zien dat 24% van het areaal de gewenste kwaliteit heeft en 20% bijna. ‘Moeras’, ‘Open duinen’, en de verschillende typen bos scoren het hoogst. De huidige versie van de EDG maakt nog gebruik van het natuurdoeltypensysteem, omdat de nieuwe SNLtypologie (SNL = Subsidiestelsel Natuur- en Landschapsbeheer) nog niet helemaal was uitgewerkt. Bij de ontwikkeling van de EDG is wel rekening gehouden dat hij ook toepasbaar gemaakt kan worden voor andere systemen, zoals Index-NL.
    Highly consistent effects of plant litter identity and functional traits on decomposition across a latitudinal gradient
    Makkonen, M. ; Berg, M.P. ; Handa, I.T. ; Hättenschwiler, S. ; Ruijven, J. van; Bodegom, P.M. van; Aerts, M.A.P.A. - \ 2012
    Ecology Letters 15 (2012)9. - ISSN 1461-023X - p. 1033 - 1041.
    tropical rain-forest - leaf-litter - terrestrial ecosystems - central argentina - carbon-cycle - rates - dynamics - climate - quality - diversity
    Plant litter decomposition is a key process in terrestrial carbon cycling, yet the relative importance of various control factors remains ambiguous at a global scale. A full reciprocal litter transplant study with 16 litter species that varied widely in traits and originated from four forest sites covering a large latitudinal gradient (subarctic to tropics) showed a consistent interspecific ranking of decomposition rates. At a global scale, variation in decomposition was driven by a small subset of litter traits (water saturation capacity and concentrations of magnesium and condensed tannins). These consistent findings, that were largely independent of the varying local decomposer communities, suggest that decomposer communities show little specialisation and high metabolic flexibility in processing plant litter, irrespective of litter origin. Our results provide strong support for using trait-based approaches in modelling the global decomposition component of biosphere-atmosphere carbon fluxes
    Near real-time disturbance detection using satellite image time series
    Verbesselt, J.P. ; Zeileis, A. ; Herold, M. - \ 2012
    Remote Sensing of Environment 123 (2012). - ISSN 0034-4257 - p. 98 - 108.
    land-surface phenology - monitoring structural-change - terrestrial ecosystems - vegetation indexes - ndvi - dynamics - patterns - exchange - models
    Near real-time monitoring of ecosystem disturbances is critical for rapidly assessing and addressing impacts on carbon dynamics, biodiversity, and socio-ecological processes. Satellite remote sensing enables cost-effective and accurate monitoring at frequent time steps over large areas. Yet, generic methods to detect disturbances within newly captured satellite images are lacking. We propose a multi-purpose time-series-based disturbance detection approach that identifies and models stable historical variation to enable change detection within newly acquired data. Satellite image time series of vegetation greenness provide a global record of terrestrial vegetation productivity over the past decades. Here, we assess and demonstrate the method by applying it to (1) simulated time series of vegetation greenness data from satellite data, (2) real-world satellite greenness image time series between February 2000 and July 2011 covering Somalia to detect drought-related vegetation disturbances. First, simulation results illustrate that disturbances are successfully detected in near real-time while being robust to seasonality and noise. Second, major drought-related disturbance corresponding with most drought-stressed regions in Somalia are detected from mid-2010 onwards. The method can analyse in-situ or satellite data time series of biophysical indicators from local to global scale since it is fast, does not depend on thresholds and does not require time series gap filling. While the data and methods used are appropriate for proof-of-concept development of global scale disturbance monitoring, specific applications (e.g., drought or deforestation monitoring) mandate integration within an operational monitoring framework
    Sampling efficiency of national, EU and global stratifications : exploring by using CL2000
    Metzger, M.J. ; Brus, D.J. ; Ortega, M. - \ 2012
    Wageningen : Alterra (Alterra report 2279) - 26
    bemonsteren - statistiek - landclassificatie - terrestrische ecosystemen - sampling - statistics - land classification - terrestrial ecosystems
    Stratification, dividing the statistical population into less heterogeneous subgroups before sampling, can help improve sampling efficiency by improving representativeness and reducing sampling error. This report explores the added sampling efficiency that is achieved by using the European Environmental stratification for estimating the area covered by the 25 Corine Land Cover (CLC) categories occurring in the semi-natural and managed terrestrial habitats of the wider-countryside. Although the dataset is not ideally suited to assess stratification efficiency for EBONE, the results give some encouragement. The analysis indicates that the pan-European stratification improves sampling efficiency for several land cover categories and performs similar to four more detailed national stratifications, supporting their use as a basis for designing a pan-European biodiversity observation network.
    Soil macroinvertebrates' abundance and diversity in home gardens in Tabasco, Mexico, vary with soil texture, organic matter and vegetation cover
    Huerta, E. ; Wal, J.C. van der - \ 2012
    European Journal of Soil Biology 50 (2012)May-June. - ISSN 1164-5563 - p. 68 - 75.
    terrestrial ecosystems - generalist predators - food-web - biodiversity - conservation - homegardens - patterns - forest - plant - agroecosystems
    We studied the composition of soil invertebrate communities and vegetation in 50 home gardens in the humid tropical lowlands of Tabasco, Mexico, located in five geomorphological regions. Five monoliths were made in each home garden and soil invertebrates were hand sorted, weighed and classified to morhospecies, functional groups and orders. We determined pH, organic matter, available phosphorus and texture in composed soil samples from each home garden. We determined the botanical name of trees, their diameter at breast height, height, and crown diameter, calculated tree density, tree cover, and biomass per hectare. We found 45 soil invertebrate morphospecies, which belonged to 12 Orders or taxonomical groups. Endogeic macroinvertebrates were significantly more abundant in the fluvial plains, hills, and mountains than in the coastal plains (F = 9.64 p <0.05). Path analysis produced a significant model, wherein soil organic matter influenced earthworm abundance (T = 3.28, p <0.05), while tree cover significantly influenced abundance of litter fragmenters (T = 3.16, p <0.05). Morphospecies richness was not related with tree species diversity. Canonical correspondence analysis with 67% of inertia on principal axes, showed how contents of soil organic matter, clay and silt were associated with earthworms abundance, while abundance of hymenoptera was associated with silt content. Interactions between plants and soil macroinvertebrates varied among regions. The coastal region showed a strong correlation between the abundance of palm trees (Coco nucifera), arachnida and isoptera morphospecies. The abundance of Gliricidia sepium in different regions showed a strong correlation with the abundance of earthworms
    Climate change threatens endangered plant species by stronger and interacting water-related stresses
    Bartholomeus, R.P. ; Witte, J.P.M. ; Bodegom, P.M. van; Dam, J.C. van; Aerts, R. - \ 2011
    Journal of Geophysical Research: Biogeosciences 116 (2011)G4. - ISSN 2169-8953
    klimaatverandering - bedreigde soorten - vegetatie - bodemwater - stress omstandigheden - droogte - ecohydrologie - climatic change - endangered species - vegetation - soil water - stress conditions - drought - ecohydrology - environmental variation - terrestrial ecosystems - hydraulic conductivity - regression quantiles - indicator values - soil-conditions - oxygen stress - root-growth - diversity
    Atmospheric CO2-concentration, temperature and rainfall variability are all expected to increase in the near future. The resulting increased dynamics of soil moisture contents, together with increased plant physiological demands for both oxygen and water, will lead to an increased occurrence of wet and dry extremes of plant stresses, i.e. of oxygen and drought stress, respectively, alone and in interaction. The use of indirect environmental variables of previous studies and their focus on one stress at a time has hampered understanding the causal impact of climate change on plant species composition through changes in abiotic site conditions. Here, we use process-based simulations of oxygen and drought stress and show that both stresses will increase (on average with ca. 20% at sites where both stresses occur) in a warmer and more variable future (2050) climate (applying a national downscaled version of IPCC scenarios). These stresses will increasingly coincide, i.e. both stresses will occur more often (but not at the same time) within the same vegetation plot. We further show that particularly this increased coincidence of water-related stresses will negatively affect the future occurrence of currently endangered plant species (a reduction of 16%), while such a decrease is not apparent for common species. Individual stresses did not affect the occurrence of endangered plant species. Consequently, the species that are already threatened under the current climate, will suffer most from climate change
    Additional carbon sequestration benefits of grassland diversity restoration
    Deyn, G.B. de; Shiel, R.S. ; Ostle, N.J. ; McNamara, N.P. ; Oakley, S. ; Young, I. ; Freeman, C. ; Fenner, N. ; Quirk, H. ; Bardgett, R.D. - \ 2011
    Journal of Applied Ecology 48 (2011)3. - ISSN 0021-8901 - p. 600 - 608.
    soil microbial community - terrestrial ecosystems - temperate grassland - upland grassland - meadow grassland - plant diversity - climate-change - nitrogen - management - vegetation
    1. In Europe, grassland agriculture is one of the dominant land uses. A major aim of European agri-environment policy is the management of grassland for botanical diversity conservation and restoration, together with the delivery of ecosystem services including soil carbon (C) sequestration. 2. To test whether management for biodiversity restoration has additional benefits for soil C sequestration, we investigated C and nitrogen (N) accumulation rates in soil and C and N pools in vegetation in a long-term field experiment (16 years) in which fertilizer application and plant seeding were manipulated. In addition, the abundance of the legume Trifolium pratense was manipulated for the last 2 years. To unravel the mechanisms underlying changes in soil C and N pools, we also tested for effects of diversity restoration management on soil structure, ecosystem respiration and soil enzyme activities. 3. We show that the long-term biodiversity restoration practices increased soil C and N storage especially when these treatments were combined with the recent promotion of the legume Trifolium pratense, sequestering 317 g C and 35 g N m-2 year-1 in the most successful management treatment. These high rates of C and N accumulation were associated with reduced ecosystem respiration, increased soil organic matter content and improved soil structure. Cessation of fertilizer use, however, reduced the amount of C and N contained in vegetation. 4. Synthesis and applications. Our findings show that long-term diversity restoration practices can yield significant benefits for soil C storage when they are combined with increased abundance of a single, sub-ordinate legume species. Moreover, we show that these management practices deliver additional ecosystem benefits such as N storage in soil and improved soil structure
    Natuurdoelen en klimaatverandering : "State-of-the-Art"
    Lototskaya, A.A. ; Geertsema, W. ; Griffioen, A.J. ; Veen, M. van der; Verdonschot, P.F.M. - \ 2011
    Wageningen : Alterra (Alterra-rapport 2135) - 156
    natuurbescherming - klimaatverandering - natuurbeleid - aquatische ecosystemen - terrestrische ecosystemen - adaptatie - veerkracht van de natuur - gevoeligheid - nederland - nature conservation - climatic change - nature conservation policy - aquatic ecosystems - terrestrial ecosystems - adaptation - resilience of nature - sensitivity - netherlands
    Er bestaat geen twijfel meer over dat klimaatverandering belangrijke gevolgen zal hebben voor de Nederlandse natuur. Enerzijds is veel bekend over de directe mechanismen van klimaatverandering en anderzijds over de ecologische eigenschappen van organismen, maar het Nederlandse beleid vraagt kennis over de specifieke gevolgen van klimaatverandering op de natuurdoelen. Wat zijn de achterliggende mechanismen van klimaatverandering in relatie tot aquatische en terrestrische ecosystemen? Dit rapport biedt een gestructureerd overzicht van directe gevolgen van klimaatverandering voor natuurdoelen en adaptatiemaatregelen voor aquatische en terrestrische natuur. Het rapport beschrijft landschapsecologische processen en functionele relaties in aquatische en terrestrische ecosystemen onder invloed van klimaatverandering, de invloed van nieuwe soortgroepen daarin, analyseert de kwetsbaarheid van natuurdoelen voor klimaatverandering en geeft een overzicht van adaptatie-maatregelen.
    Effects of plant-soil feedback on tree seedling growth under arid conditions
    Meijer, S.S. ; Holmgren, M. ; Putten, W.H. van der - \ 2011
    Journal of Plant Ecology 4 (2011)4. - ISSN 1752-9921 - p. 193 - 200.
    arbuscular mycorrhizal fungi - terrestrial ecosystems - semiarid ecosystems - resource pulses - atacama desert - establishment - competition - community - diversity - dynamics
    Aims: Plants are able to influence their growing environment by changing biotic and abiotic soil conditions. These soil conditions in turn can influence plant growth conditions, which is called plant–soil feedback. Plant–soil feedback is known to be operative in a wide variety of ecosystems ranging from temperate grasslands to tropical rain forests. However, little is known about how it operates in arid environments. We examined the role of plant–soil feedbacks on tree seedling growth in relation to water availability as occurring in arid ecosystems along the west coast of South America. Methods: In a two-phased greenhouse experiment, we compared plant–soil feedback effects under three water levels (no water, 10% gravimetric moisture and 15% gravimetric moisture). We used sterilized soil inoculated with soil collected from northwest Peru (Prosopis pallida forests) and from two sites in north-central Chile (Prosopis chilensis forest and scrublands without P. chilensis). Important Findings: Plant–soil feedbacks differed between plant species and soil origins, but water availability did not influence the feedback effects. Plant–soil feedbacks differed in direction and strength in the three soil origins studied. Plant–soil feedbacks of plants grown in Peruvian forest soil were negative for leaf biomass and positive for root length. In contrast, feedbacks were neutral for plants growing in Chilean scrubland soil and positive for leaf biomass for those growing in Chilean forest soil. Our results show that under arid conditions, effects of plant–soil feedback depend upon context. Moreover, the results suggest that plant–soil feedback can influence trade-offs between root growth and leaf biomass investment and as such that feedback interactions between plants and soil biota can make plants either more tolerant or vulnerable to droughts. Based on dissecting plant–soil feedbacks into aboveground and belowground tissue responses, we conclude that plant–soil feedback can enhance plant colonization in some arid ecosystems by promoting root growth
    Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses: a meta-analysis
    Limpens, J. ; Granath, G. ; Gunnarson, U. ; Hoosbeek, M.R. ; Heijmans, M.M.P.D. - \ 2011
    New Phytologist 191 (2011)2. - ISSN 0028-646X - p. 496 - 507.
    global change - nutritional constraints - terrestrial ecosystems - carbon accumulation - species richness - ombrotrophic bog - vascular plants - n deposition - water-table - growth
    • Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain.• Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data.• We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increasedannual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m-2 yr-1 for each 1°C increase.• Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation
    Challenges in using land use and land cover data for global change studies
    Verburg, P.H. ; Neumann, K. ; Nol, L. - \ 2011
    Global Change Biology 17 (2011)2. - ISSN 1354-1013 - p. 974 - 989.
    conterminous united-states - terrestrial ecosystems - accuracy assessment - satellite imagery - dependent errors - water-resources - uncertainty - climate - maps - system
    Land use and land cover data play a central role in climate change assessments. These data originate from different sources and inventory techniques. Each source of land use/cover data has its own domain of applicability and quality standards. Often data are selected without explicitly considering the suitability of the data for the specific application, the bias originating from data inventory and aggregation, and the effects of the uncertainty in the data on the results of the assessment. Uncertainties due to data selection and handling can be in the same order of magnitude as uncertainties related to the representation of the processes under investigation. While acknowledging the differences in data sources and the causes of inconsistencies, several methods have been developed to optimally extract information from the data and document the uncertainties. These methods include data integration, improved validation techniques and harmonization of classification systems. Based on the data needs of global change studies and the data availability, recommendations are formulated aimed at optimal use of current data and focused efforts for additional data collection. These include: improved documentation using classification systems for land use/cover data; careful selection of data given the specific application and the use of appropriate scaling and aggregation methods. In addition, the data availability may be improved by the combination of different data sources to optimize information content while collection of additional data must focus on validation of available data sets and improved coverage of regions and land cover types with a high level of uncertainty. Specific attention in data collection should be given to the representation of land management (systems) and mosaic landscapes
    Modelling the impact of nitrogen deposition, climate change and nutrient limitations on tree carbon sequestration in Europe for the period 1900–2050
    Vries, W. de; Posch, M. - \ 2011
    Environmental Pollution 159 (2011)10. - ISSN 0269-7491 - p. 2289 - 2299.
    forest ecosystems - elevated co2 - terrestrial ecosystems - primary productivity - tropospheric ozone - temperate forests - projected changes - acid deposition - boreal forests - douglas-fir
    We modelled the combined effects of past and expected future changes in climate and nitrogen deposition on tree carbon sequestration by European forests for the period 1900–2050. Two scenarios for deposition (current legislation and maximum technically feasible reductions) and two climate scenarios (no change and SRES A1 scenario) were used. Furthermore, the possible limitation of forest growth by calcium, magnesium, potassium and phosphorus is investigated. The area and age structure of the forests was assumed to stay constant to observations during the period 1970–1990. Under these assumptions, the simulations show that the change in forest growth and carbon sequestration in the past is dominated by changes in nitrogen deposition, while climate change is the major driver for future carbon sequestration. However, its impact is reduced by nitrogen availability. Furthermore, limitations in base cations, especially magnesium, and in phosphorus may significantly affect predicted growth in the future. A modelling exercise indicates that nitrogen deposition mainly enhanced tree carbon sequestration in Europe in the past, while climate change will do so in the future
    Semiempirical modeling of abiotic and biotic factors controlling ecosystem respiration across eddy covariance sites
    Migliavacca, M. ; Reichstein, M. ; Richardson, A.D. ; Colombo, R. ; Sutton, M.A. ; Lasslop, G. ; Tomelleri, E. ; Wohlfahrt, G. ; Carvalhais, N. ; Molen, M.K. van der - \ 2011
    Global Change Biology 17 (2011)1. - ISSN 1354-1013 - p. 390 - 409.
    forest soil respiration - carbon-dioxide exchange - water-vapor exchange - deciduous forest - european forests - heterotrophic components - rhizosphere respiration - terrestrial ecosystems - litter decomposition - nitrogen deposition
    In this study we examined ecosystem respiration (RECO) data from 104 sites belonging to FLUXNET, the global network of eddy covariance flux measurements. The goal was to identify the main factors involved in the variability of RECO: temporally and between sites as affected by climate, vegetation structure and plant functional type (PFT) (evergreen needleleaf, grasslands, etc.). We demonstrated that a model using only climate drivers as predictors of RECO failed to describe part of the temporal variability in the data and that the dependency on gross primary production (GPP) needed to be included as an additional driver of RECO. The maximum seasonal leaf area index (LAIMAX) had an additional effect that explained the spatial variability of reference respiration (the respiration at reference temperature Tref515 1C, without stimulation introduced by photosynthetic activity and without water limitations), with a statistically significant linear relationship (r250.52, Po0.001, n5104) even within each PFT. Besides LAIMAX, we found that reference respiration may be explained partially by total soil carbon content (SoilC). For undisturbed temperate and boreal forests a negative control of total nitrogen deposition (Ndepo) on reference respiration was also identified. We developed a new semiempirical model incorporating abiotic factors (climate), recent productivity (daily GPP), general site productivity and canopy structure (LAIMAX) which performed well in predicting the spatio-temporal variability of RECO, explaining 470% of the variance for most vegetation types. Exceptions include tropical and Mediterranean broadleaf forests and deciduous broadleaf forests. Part of the variability in respiration that could not be described by our model may be attributed to a series of factors, including phenology in deciduous broadleaf forests and management practices in grasslands and croplands
    Assessing the Impacts of Long-Range Sulfur and Nitrogen Deposition on Arctic and Sub-Arctic Ecosystems
    Forsius, M. ; Posch, M. ; Aherne, J. ; Reinds, G.J. ; Christensen, J. ; Hole, L. - \ 2010
    Ambio 39 (2010)2. - ISSN 0044-7447 - p. 136 - 147.
    critical loads - terrestrial ecosystems - forest ecosystems - air-pollution - model - soil - acidification - uncertainty - simulation - pechenga
    For more than a decade, anthropogenic sulfur (S) and nitrogen (N) deposition has been identified as a key pollutant in the Arctic. In this study new critical loads of acidity (S and N) were estimated for terrestrial ecosystems north of 60A degrees latitude by applying the Simple Mass Balance (SMB) model using two critical chemical criteria (Al/Bc = 1 and ANC(le) = 0). Critical loads were exceeded in large areas of northern Europe and the Norilsk region in western Siberia during the 1990s, with the more stringent criterion (ANC(le) = 0) showing the larger area of exceedance. However, modeled deposition estimates indicate that mean concentrations of sulfur oxides and total S deposition within the Arctic almost halved between 1990 and 2000. The modeled exceeded area is much reduced when currently agreed emission reductions are applied, and almost disappears under the implementation of maximum technically feasible reductions by 2020. In northern North America there was no exceedance under any of the deposition scenarios applied. Modeled N deposition was less than 5 kg ha(-1) y(-1) almost across the entire study area for all scenarios; and therefore empirical critical loads for the eutrophying impact of nitrogen are unlikely to be exceeded. The reduction in critical load exceedances is supported by observed improvements in surface water quality, whereas the observed extensive damage of terrestrial vegetation around the mining and smelter complexes in the area is mainly caused by direct impacts of air pollution and metals.
    Natuurwaarde 2.0 land : graadmeter natuurkwaliteit landecosystemen voor nationale beleidsdoelen
    Reijnen, M.J.S.M. ; Hinsberg, A. van; Esbroek, M.L.P. van; Knegt, B. de; Pouwels, R. ; Tol, S. van; Wiertz, J. - \ 2010
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-rapport 110) - 116
    flora - fauna - terrestrische ecosystemen - ecosystemen - monitoring - indicatoren - natuurgebieden - natuurontwikkeling - nederland - flora - fauna - terrestrial ecosystems - ecosystems - monitoring - indicators - natural areas - nature development - netherlands
    De graadmeter Natuurwaarde 2.0 geeft een beeld van de jaarlijkse veranderingen in de gemiddelde ecosysteemkwaliteit van natuurgebieden in Nederland, sinds 1994. De gemiddelde Ecosysteemkwaliteit is bepaald op basis van de NEM-meetnetten voor vogels, vlinders, planten en reptielen (NEM = Netwerk Ecologische Monitoring). De onderscheiden ecosystemen zijn: bos, heide, open duin, moeras en halfnatuurlijk grasland; voor het agrarische gebied blijkt het aantal NEM-meetpunten voor planten nog onvoldoende. Methodologisch is deze versie 2 sterk verbeterd doordat deze qua rekenmethode, indeling van ecosysteemtypen en soortselectie beter aansluit op het beleid, nu deze ook jaarlijks bepaald kan worden. De methode is in principe consistent met die van de Kaderrichtlijn Water (KRW), Natura 2000 en de Europese SEBI (Streamlining European Biodiversity Indicators) en mondiale CBD-richtlijnen (CBD = Convention on Biological Diversity). Zo kan bijvoorbeeld de 2010- doelstelling getoetst worden. Verder wordt de graadmeter Natuurwaarde 2.0 geplaatst en bediscussieerd in het raamwerk van de overige natuurindicatoren van het Planbureau voor de Leefomgeving. Trefwoorden: natuurgraadmeter, ecosysteemkwaliteit, landnatuur, doelsoorten, intact ecosysteem
    Biodiversiteit voor de BES-eilanden: Bonaire, St. Eustatius en Saba : onderzoeksvragen en verplichtingen
    Jongman, R.H.G. ; Meesters, H.W.G. ; Debrot, A.O. - \ 2010
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2080) - 65
    biodiversiteit - mariene gebieden - natuurbescherming - bonaire - sint eustatius - saba - terrestrische ecosystemen - biodiversity - marine areas - nature conservation - bonaire - sint eustatius - saba - terrestrial ecosystems
    Dit rapport geeft een overzicht van de biodiversiteit op en rond de eilanden Bonaire, St. Eustatius en Saba (BES) en de verplichtingen die voortkomen uit verdragen waar op dit moment de Nederlandse Antillen aan gebonden is. Het rapport geeft verder de belangrijkste onderzoeksprioriteiten, gerelateerd aan deze internationale verplichtingen voor zowel de mariene als de terrestrische biodiversiteit.
    The trait contribution to wood decomposition rates of 15 neotropical tree species
    Geffen, K.G. van; Poorter, L. ; Sass-Klaassen, U. ; Logtestijn, R.S.P. ; Cornelissen, J.H.C. - \ 2010
    Ecology 91 (2010)12. - ISSN 0012-9658 - p. 3686 - 3697.
    leaf-litter decomposition - life-history variation - tropical forests - climate-change - silvicultural treatments - terrestrial ecosystems - economics spectrum - boreal forests - carbon balance - central amazon
    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of inter-specific variation in species traits on differences wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest, and hypothesized that inter-specific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr-1. We measured 10 different chemical, anatomical and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (DBH) of the tree species (R2=0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2=0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When DBH values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree DBH and lignin concentration) explained even more variation in wood decomposition rates (R2=0.71), underlining the importance of DBH in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the
    Semi-field methods for the environmental risk assessment of pesticides in soil
    Schaeffer, A. ; Brink, P.J. van den; Heimbach, F. ; Hoy, S. ; Jong, F.W.M. de; Rombke, J. - \ 2010
    SETAC America : Pensacola and Boca Raton (Fl): SETAC and CRC Press - ISBN 9781439828588 - 144
    pesticiden - risicoschatting - methodologie - terrestrische ecosystemen - bodembiologie - milieu - regelingen - experimenteel veldonderzoek - pesticides - risk assessment - methodology - terrestrial ecosystems - soil biology - environment - regulations - field experimentation
    Management effects on net ecosystem carbon and GHG budgets at European crop sites
    Ceschia, E. ; Beziat, P. ; Dejoux, J.F. ; Elbers, J.A. ; Jacobs, C.M.J. ; Jans, W.W.P. - \ 2010
    Agriculture, Ecosystems and Environment 139 (2010)3. - ISSN 0167-8809 - p. 363 - 383.
    rain-fed maize - greenhouse-gas emissions - north central region - soil organic-carbon - no-till ecosystem - eddy covariance - dioxide exchange - co2 flux - terrestrial ecosystems - biome productivity
    The greenhouse gas budgets of 15 European crop sites covering a large climatic gradient and corresponding to 41 site-years were estimated. The sites included a wide range of management practices (organic and/or mineral fertilisation, tillage or ploughing, with or without straw removal, with or without irrigation, etc.) and were cultivated with 15 representative crop species common to Europe. At all sites, carbon inputs (organic fertilisation and seeds), carbon exports (harvest or fire) and net ecosystem production (NEP), measured with the eddy covariance technique, were calculated. The variability of the different terms and their relative contributions to the net ecosystem carbon budget (NECB) were analysed for all site-years, and the effect of management on NECB was assessed. To account for greenhouse gas (GHG) fluxes that were not directly measured on site, we estimated the emissions caused by field operations (EFO) for each site using emission factors from the literature. The EFO were added to the NECB to calculate the total GHG budget (GHGB) for a range of cropping systems and management regimes. N2O emissions were calculated following the IPCC (2007) guidelines, and CH4 emissions were estimated from the literature for the rice crop site only. At the other sites, CH4 emissions/oxidation were assumed to be negligible compared to other contributions to the net GHGB. Finally, we evaluated crop efficiencies (CE) in relation to global warming potential as the ratio of C exported from the field (yield) to the total GHGB. On average, NEP was negative (-284 ± 228 g C m-2 year-1), and most cropping systems behaved as atmospheric sinks, with sink strength generally increasing with the number of days of active vegetation. The NECB was, on average, 138 ± 239 g C m-2 year-1, corresponding to an annual loss of about 2.6 ± 4.5% of the soil organic C content, but with high uncertainty. Management strongly influenced the NECB, with organic fertilisation tending to lower the ecosystem carbon budget. On average, emissions caused by fertilisers (manufacturing, packaging, transport, storage and associated N2O emissions) represented close to 76% of EFO. The operation of machinery (use and maintenance) and the use of pesticides represented 9.7 and 1.6% of EFO, respectively. On average, the NEP (through uptake of CO2) represented 88% of the negative radiative forcing, and exported C represented 88% of the positive radiative forcing of a mean total GHGB of 203 ± 253 g C-eq m-2 year-1. Finally, CE differed considerably among crops and according to management practices within a single crop. Because the CE was highly variable, it is not suitable at this stage for use as an emission factor for management recommendations, and more studies are needed to assess the effects of management on crop efficiency.
    Predicting species distribution and abundance responses to climate change: why it is essential to include biotic interactions across trophic levels
    Putten, W.H. van der; Macel, M. ; Visser, M. de - \ 2010
    Philosophical Transactions of the Royal Society B. Biological sciences 365 (2010)1549. - ISSN 0962-8436 - p. 2025 - 2034.
    coast salt marshes - habitat fragmentation - insect herbivores - terrestrial ecosystems - spatial-distribution - mycorrhizal fungi - local adaptation - migration rates - plant diversity - arctic tundra
    Current predictions on species responses to climate change strongly rely on projecting altered environmental conditions on species distributions. However, it is increasingly acknowledged that climate change also influences species interactions. We review and synthesize literature information on biotic interactions and use it to argue that the abundance of species and the direction of selection during climate change vary depending on how their trophic interactions become disrupted. Plant abundance can be controlled by aboveground and belowground multitrophic level interactions with herbivores, pathogens, symbionts and their enemies. We discuss how these interactions may alter during climate change and the resulting species range shifts. We suggest conceptual analogies between species responses to climate warming and exotic species introduced in new ranges. There are also important differences: the herbivores, pathogens and mutualistic symbionts of range-expanding species and their enemies may co-migrate, and the continuous gene flow under climate warming can make adaptation in the expansion zone of range expanders different from that of cross-continental exotic species. We conclude that under climate change, results of altered species interactions may vary, ranging from species becoming rare to disproportionately abundant. Taking these possibilities into account will provide a new perspective on predicting species distribution under climate change.
    Influence of spring and autumn phenological transitions on forest ecosystem productivit
    Richardson, A.D. ; Black, T.A. ; Ciais, P. ; Delbart, N. ; Moors, E.J. - \ 2010
    Philosophical Transactions of the Royal Society B. Biological sciences 365 (2010). - ISSN 0962-8436 - p. 3227 - 3246.
    growing-season length - sub-alpine forest - deciduous forest - climate-change - boreal forest - co2 exchange - interannual variability - carbon sequestration - terrestrial ecosystems - temporal variation
    We use eddy covariance measurements of net ecosystem productivity (NEP) from 21 FLUXNET sites (153 site-years of data) to investigate relationships between phenology and productivity (in terms of both NEP and gross ecosystem photosynthesis, GEP) in temperate and boreal forests. Results are used to evaluate the plausibility of four different conceptual models. Phenological indicators were derived from the eddy covariance time series, and from remote sensing and models. We examine spatial patterns (across sites) and temporal patterns (across years); an important conclusion is that it is likely that neither of these accurately represents how productivity will respond to future phenological shifts resulting from ongoing climate change. In spring and autumn, increased GEP resulting from an ‘extra’ day tends to be offset by concurrent, but smaller, increases in ecosystem respiration, and thus the effect on NEP is still positive. Spring productivity anomalies appear to have carry-over effects that translate to productivity anomalies in the following autumn, but it is not clear that these result directly from phenological anomalies. Finally, the productivity of evergreen needleleaf forests is less sensitive to phenology than is productivity of deciduous broadleaf forests. This has implications for how climate change may drive shifts in competition within mixed-species stands.
    Variations in constitutive and inducible UV-B tolerance; dissecting photosystem II protection in Arabidopsis thaliana accessions
    Jansen, M.A.K. ; LeMartret, B. ; Koornneef, M. - \ 2010
    Physiologia Plantarum 138 (2010)1. - ISSN 0031-9317 - p. 22 - 34.
    ultraviolet-radiation - genetic-variation - chlorophyll fluorescence - terrestrial ecosystems - balancing damage - higher-plants - responses - stress - expression - light
    The rise in ultraviolet-B (UV-B) (280–315 nm) radiation levels, that is a consequence of stratospheric ozone layer depletion, has triggered extensive research on the effects of UV-B on plants. Plants raised under natural sunlight conditions are generally well protected from the potentially harmful effects of UV-B radiation. However, it is mostly unknown to which extent UV protection is constitutive and/or induced. In this study, we have analysed the role of constitutive and inducible protection responses in avoiding UV-B damage to photosystem II of photosynthesis. We have assayed the UV susceptibility of photosystem II in 224 Arabidopsis thaliana accessions from across the Northern hemisphere, and found a continuum of constitutive UV-protection levels, with some accessions being UV sensitive and others UV tolerant. Statistical analysis showed only very weak associations between constitutive UV tolerance and the geographic origin of accessions. Instead, most of the variance in constitutive UV-B protection of photosynthesis is present at the level of local Arabidopsis populations originating in the same geographic and climatic area. The variance in constitutive UV protection is, however, small compared to the amplitude of environmentally induced changes in UV protection. Thus, our data emphasise the importance of inducible responses for the protection of photosystem II against UV-B. Remarkably, the conditions that induce UV-protective responses vary; accessions from lower latitudes were found to switch-on UV defences more readily than those of higher latitudes. Such altered regulation of induction may comprise a suitable adaptation response when levels of a stressor are fluctuating in the short term, but predictable over longer periods
    Uncertainties in critical loads and target loads of sulphur and nitrogen for European forests: Analysis and quantification
    Reinds, G.J. ; Vries, W. de - \ 2010
    Science of the Total Environment 408 (2010)8. - ISSN 0048-9697 - p. 1960 - 1970.
    soil acidification model - quantifying uncertainty - terrestrial ecosystems - atmospheric deposition - bayesian calibration - acid deposition - aluminum - sensitivity - solubility - horizons
    An analysis of the uncertainties in critical loads and target loads of sulphur (S) and nitrogen (N) for 182 European forest soils was carried out using the Very Simple Dynamic (VSD) model. The VSD model was calibrated with a Bayesian approach using prior probability functions for model parameters based on literature data, data from 200 Dutch forest sites and from simulated denitrification rates from a detailed ecosystem model. The calibration strongly improved the fit of the model to observed soil and soil solution concentrations, especially for pH and base saturation. Calibration also narrowed down the ranges in input parameters. The uncertainty analysis showed which parameters contribute most to the uncertainty in the critical loads and target loads. Base cation weathering and deposition and the parameters describing the H–Al equilibrium in the soil solution determine the uncertainty in the maximum critical loads for S, CLmax(S), when based on the aluminium to base cation (Al/Bc) criterion. Uncertainty in CLmax(S) based on an acid neutralizing capacity (ANC) criterion is completely determined by base cation inputs alone. The denitrification fraction is the most important source of uncertainty for the maximum critical loads of N, CLmax(N). N uptake and N immobilisation determine the uncertainties in the critical load for N as a nutrient, CLnut(N). Calibration of VSD reduced the uncertainty: the coefficient of variation (CV) was reduced for all critical loads and criteria. After calibration, the CV for CLmax(S) was below 0.4 for almost all plots; however for CLmax(N) high values occurred for plots with high denitrification rates. Model calibration also improved the robustness of target load estimates: after calibration, no target loads were needed in any of the simulations for 40% of the plots, with the uncalibrated model there was a positive probability for the need of a target load for almost all plots
    Savanna aliens
    Masocha, M. - \ 2010
    Wageningen University. Promotor(en): Andrew Skidmore; Herbert Prins, co-promotor(en): Milena Holmgren Urba. - [S.l. : S.n. - ISBN 9789085856191 - 161
    savannen - ecosystemen - invasies - onkruiden - houtige onkruiden - gedegradeerd land - habitat vernietiging - isoptera - verbranden - geografische informatiesystemen - ecologische verstoring - verstoord land - monitoring - afrika - terrestrische ecosystemen - milieumonitoring - savannas - ecosystems - invasions - weeds - woody weeds - degraded land - habitat destruction - isoptera - burning - geographical information systems - ecological disturbance - disturbed land - monitoring - africa - terrestrial ecosystems - environmental monitoring
    Numerous alien plant species are invading African savannas causing loss of biodiversity and altering ecosystem functioning. The ecological factors and underlying mechanisms causing these invasions are poorly understood. This hinders invasive species management and biodiversity conservation. In this thesis, a range of approaches (i.e., field measurements, a greenhouse experiment, field experiments, a long-term burning experiment, remote sensing, and Geographical Information System (GIS) techniques) was used to understand how the availability of two key resources limiting primary productivity in African savannas (water and nutrients) and how major disturbances (i.e., fire, grazing) determine the invasion of these systems by alien plant species.
    The European carbon balance: part 3: Forests
    Luyssaert, S. ; Ciais, P. ; Piao, S.L. ; Schulze, E.D. ; Jung, M. ; Zaehle, S. ; Schelhaas, M.J. ; Reichstein, M. ; Churkina, G. ; Papale, D. ; Abril, G. ; Beer, C. ; Grace, J. ; Loustau, D. ; Matteucci, G. ; Magnani, F. ; Nabuurs, G.J. ; Verbeeck, H. ; Sulkava, M. ; Werf, G.R. van der; Janssens, I.A. - \ 2010
    Global Change Biology 16 (2010)5. - ISSN 1354-1013 - p. 1429 - 1450.
    dissolved organic-carbon - reduces soil respiration - northern hardwood forest - old-growth forests - climate-change - nitrogen additions - terrestrial ecosystems - temperate forests - global database - wide reduction
    We present a new synthesis, based on a suite of complementary approaches, of the primary production and carbon sink in forests of the 25 member states of the European Union (EU-25) during 1990–2005. Upscaled terrestrial observations and model-based approaches agree within 25% on the mean net primary production (NPP) of forests, i.e. 520±75 g C m-2 yr-1 over a forest area of 1.32 × 106 km2 to 1.55 × 106 km2 (EU-25). New estimates of the mean long-term carbon forest sink (net biome production, NBP) of EU-25 forests amounts 75±20 g C m-2 yr-1. The ratio of NBP to NPP is 0.15±0.05. Estimates of the fate of the carbon inputs via NPP in wood harvests, forest fires, losses to lakes and rivers and heterotrophic respiration remain uncertain, which explains the considerable uncertainty of NBP. Inventory-based assessments and assumptions suggest that 29±15% of the NBP (i.e., 22 g C m-2 yr-1) is sequestered in the forest soil, but large uncertainty remains concerning the drivers and future of the soil organic carbon. The remaining 71±15% of the NBP (i.e., 53 g C m-2 yr-1) is realized as woody biomass increments. In the EU-25, the relatively large forest NBP is thought to be the result of a sustained difference between NPP, which increased during the past decades, and carbon losses primarily by harvest and heterotrophic respiration, which increased less over the same period
    Carbon and nitrogen balances for six shrublands across Europe
    Beier, C. ; Emmett, B.A. ; Tietema, A. ; Schmidt, I.K. ; Penuelas, J. ; Lang, E.K. ; Duce, P. ; Angelis, P. de; Gorissen, A. ; Estiarte, M. ; Dato, G.D. de; Sowerby, A. ; Kroel-Dulay, G. ; Lellei-Kovacs, E. ; Kull, O. ; Mand, P. ; Petersen, H. ; Gjelstrup, P. ; Spano, D. - \ 2009
    Global Biogeochemical Cycles 23 (2009). - ISSN 0886-6236 - 13 p.
    microbial biomass-c - climate-change - terrestrial ecosystems - soil respiration - forest ecosystems - extraction method - global patterns - elevated co2 - drought - responses
    Shrublands constitute significant and important parts of European landscapes providing a large number of important ecosystem services. Biogeochemical cycles in these ecosystems have gained little attention relative to forests and grassland systems, but data on such cycles are required for developing and testing ecosystem models. As climate change progresses, the potential feedback from terrestrial ecosystems to the atmosphere through changes in carbon stocks, carbon sequestration, and general knowledge on biogeochemical cycles becomes increasingly important. Here we present carbon and nitrogen balances of six shrublands along a climatic gradient across the European continent. The aim of the study was to provide a basis for assessing the range and variability in carbon storage in European shrublands. Across the sites the net carbon storage in the systems ranged from 1,163 g C m(-2) to 18,546 g C m(-2), and the systems ranged from being net sinks (126 g C m(-2) a(-1)) to being net sources (-536 g C m(-2) a(-1)) of carbon with the largest storage and sink of carbon at wet and cold climatic conditions. The soil carbon store dominates the carbon budget at all sites and in particular at the site with a cold and wet climate where soil C constitutes 95% of the total carbon in the ecosystem. Respiration of carbon from the soil organic matter pool dominated the carbon loss at all sites while carbon loss from aboveground litter decomposition appeared less important. Total belowground carbon allocation was more than 5 times aboveground litterfall carbon which is significantly greater than the factor of 2 reported in a global analysis of forest data. Nitrogen storage was also dominated by the soil pools generally showing small losses except when atmospheric N input was high. The study shows that in the future a climate-driven land cover change between grasslands and shrublands in Europe will likely lead to increased ecosystem C where shrublands are promoted and less where grasses are promoted. However, it also emphasizes that if feedbacks on the global carbon cycle are to be predicted it is critically important to quantify and understand belowground carbon allocation and processes as well as soil carbon pools, particularly on wet organic soils, rather than plant functional change as the soil stores dominate the overall budget and fluxes of carbon
    Paradoxical differences in N-dynamics between Luxembourg soils: litter quality or parent material?
    Kooijman, A.M. ; Smit, A. - \ 2009
    European Journal of Forest Research 128 (2009)6. - ISSN 1612-4669 - p. 555 - 565.
    gross nitrogen transformations - organic-matter - beech forests - terrestrial ecosystems - humus forms - mineralization - decomposition - availability - patterns - earthworms
    To explore whether litter quality could alter differences in N-dynamics between soil types, we compared spruce and beech growing on soils with parent material sandstone and limestone, and beech and hornbeam on acid marl and limestone. We measured pH, organic matter content, C:N ratio, soil respiration and net N-mineralization of the organic layer and the mineral topsoil in a laboratory incubation experiment and estimated gross N-mineralization and immobilization with a simulation model. Species effects were restricted to the organic layer, but higher mass for low-degradable species was compensated by higher process rates for high-degradable ones, so N-dynamics per square metre did not differ. Also, the mineral topsoil was not affected by litter quality, which may have been overruled by soil conditions. Forest soils formed from different parent materials, however, clearly differed in N-dynamics, although different from expectations for net N-mineralization. Sandstone showed low respiration and gross N-mineralization, but net N-mineralization was higher than expected, probably due to low microbial N-demand. In contrast, limestone, and to some extent acid marl, showed high respiration and gross N-release, but lower net N-mineralization than expected, because microbial immobilization was also high. Simulated gross N-mineralization even showed a negative instead of positive correlation with net N-mineralization, probably due to the strong increase in immobilization when gross N-mineralization is high. The shift in microbial N-demand may in turn be related to a more general shift from bacteria to fungi over pH-gradients.
    The impact of nitrogen deposition on carbon sequestration by European forests and heathlands
    Vries, W. de; Solberg, S. ; Dobbertin, M. ; Sterba, H. ; Laubhann, D. ; Oijen, M. van; Evans, C. ; Gundersen, P. ; Kros, H. ; Wamelink, W. ; Reinds, G.J. ; Sutton, M.A. - \ 2009
    Forest Ecology and Management 258 (2009)8. - ISSN 0378-1127 - p. 1814 - 1823.
    atmospheric nitrogen - temperate forest - terrestrial ecosystems - harvard forest - mineral soil - n deposition - saturation - additions - growth - fertilization
    In this study, we present estimated ranges in carbon (C) sequestration per kg nitrogen (N) addition in above-ground biomass and in soil organic matter for forests and heathlands, based on: (i) empirical relations between spatial patterns of carbon uptake and influencing environmental factors including nitrogen deposition (forests only), (ii) 15N field experiments, (iii) long-term low-dose N fertilizer experiments and (iv) results from ecosystem models. The results of the various studies are in close agreement and show that above-ground accumulation of carbon in forests is generally within the range 15–40 kg C/kg N. For heathlands, a range of 5–15 kg C/kg N has been observed based on low-dose N fertilizer experiments. The uncertainty in C sequestration per kg N addition in soils is larger than for above-ground biomass and varies on average between 5 and 35 kg C/kg N for both forests and heathlands. All together these data indicate a total carbon sequestration range of 5–75 kg C/kg N deposition for forest and heathlands, with a most common range of 20–40 kg C/kg N. Results cannot be extrapolated to systems with very high N inputs, nor to other ecosystems, such as peatlands, where the impact of N is much more variable, and may range from C sequestration to C losses
    Temporal and among-site variability of inherent water use efficiency at the ecosystem level
    Beer, C. ; Ciais, P. ; Reichstein, M. ; Baldocchi, D. ; Law, B.E. ; Papale, D. ; Soussana, J.F. ; Ammann, C. ; Buchmann, N. ; Frank, D. ; Gianelle, D. ; Janssens, I.A. ; Knohl, A. ; Kostner, B. ; Moors, E.J. ; Roupsard, O. ; Verbeeck, H. ; Vesala, T. ; Williams, C.A. ; Wohlfahrt, G. - \ 2009
    Global Biogeochemical Cycles 23 (2009). - ISSN 0886-6236 - 13
    watergebruiksrendement - kooldioxide - waterdampbeweging - terrestrische ecosystemen - atmosfeer - koolstofcyclus - water use efficiency - carbon dioxide - water vapour movement - terrestrial ecosystems - atmosphere - carbon cycle - scots pine forest - co2 exchange - carbon-dioxide - eddy covariance - central germany - ponderosa pine - canopy-scale - aspen forest - beech forest - time scales
    Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities represents ecosystem water use efficiency. Its multiplication with mean daylight vapor pressure deficit (VPD) leads to a quantity which we call “inherent water use efficiency” (IWUE*). The dependence of IWUE* on environmental conditions indicates possible adaptive adjustment of ecosystem physiology in response to a changing environment. IWUE* is analyzed for 43 sites across a range of plant functional types and climatic conditions. IWUE* increases during short-term moderate drought conditions. Mean annual IWUE* varied by a factor of 3 among all sites. This is partly explained by soil moisture at field capacity, particularly in deciduous broad-leaved forests. Canopy light interception sets the upper limits to canopy photosynthesis, and explains half the variance in annual IWUE* among herbaceous ecosystems and evergreen needle-leaved forests. Knowledge of IWUE* offers valuable improvement to the representation of carbon and water coupling in ecosystem process models
    Empirical and theoretical challenges in aboveground-belowground ecology
    Putten, W.H. van der; Bardgett, R.D. ; Ruiter, P.C. de; Hol, W.H.G. ; Meyer, K.M. ; Bezemer, T.M. ; Bradford, M.A. ; Christensen, S. ; Eppinga, M.B. ; Fukami, T. ; Hemerik, L. ; Molofsky, J. ; Schädler, M. ; Scherber, C. ; Strauss, S.Y. ; Vos, M. ; Wardle, D.A. - \ 2009
    Oecologia 161 (2009)1. - ISSN 0029-8549 - p. 1 - 14.
    plant-soil feedback - increased competitive ability - climate-change - community composition - trophic interactions - insect herbivory - enemy release - food-web - terrestrial ecosystems - grassland ecosystems
    A growing body of evidence shows that aboveground and belowground communities and processes are intrinsically linked, and that feedbacks between these subsystems have important implications for community structure and ecosystem functioning. Almost all studies on this topic have been carried out from an empirical perspective and in specific ecological settings or contexts. Belowground interactions operate at different spatial and temporal scales. Due to the relatively low mobility and high survival of organisms in the soil, plants have longer lasting legacy effects belowground than aboveground. Our current challenge is to understand how aboveground¿belowground biotic interactions operate across spatial and temporal scales, and how they depend on, as well as influence, the abiotic environment. Because empirical capacities are too limited to explore all possible combinations of interactions and environmental settings, we explore where and how they can be supported by theoretical approaches to develop testable predictions and to generalise empirical results. We review four key areas where a combined aboveground¿belowground approach offers perspectives for enhancing ecological understanding, namely succession, agro-ecosystems, biological invasions and global change impacts on ecosystems. In plant succession, differences in scales between aboveground and belowground biota, as well as between species interactions and ecosystem processes, have important implications for the rate and direction of community change. Aboveground as well as belowground interactions either enhance or reduce rates of plant species replacement. Moreover, the outcomes of the interactions depend on abiotic conditions and plant life history characteristics, which may vary with successional position. We exemplify where translation of the current conceptual succession models into more predictive models can help targeting empirical studies and generalising their results. Then, we discuss how understanding succession may help to enhance managing arable crops, grasslands and invasive plants, as well as provide insights into the effects of global change on community re-organisation and ecosystem processes
    Ectomycorrhizal fungi associated with Pinus sylvestris seedlings respond differently to increased carbon and nitrogen availability: implications for ecosystem responses to global change.
    Alberton, O. ; Kuyper, T.W. - \ 2009
    Global Change Biology 15 (2009)1. - ISSN 1354-1013 - p. 166 - 175.
    elevated atmospheric co2 - progressive n limitation - douglas-fir seedlings - terrestrial ecosystems - deposition gradient - mycorrhizal fungal - community change - soil biota - dioxide - metaanalysis
    The ectomycorrhizal (ECM) symbiosis can cause both positive and negative feedback with trees under elevated CO2. Positive feedback arises if the additional carbon (C) increases both nutrient uptake by the fungus and nutrient transfer to the plant, whereas negative feedback results from increased nutrient uptake and immobilization by the fungus and reduced transfer to the plant. Because species of ECM fungi differ in their C and nitrogen (N) demand, understanding fungal species-specific responses to variation in C and N supply is essential to predict impacts of global change. We investigated fungal species-specific responses of ECM Scots pine (Pinus sylvestris) seedlings under ambient and elevated CO2 (350 or 700 ¿L L¿1 CO2) and under low and high mineral N availability. Each seedling was associated with one of the following ECM species: Hebeloma cylindrosporum, Laccaria bicolor and Suillus bovinus. The experiment lasted 103 days. During the final 27 days, seedlings were labeled with 14CO2 and 15N. Most plant and fungal parameters were significantly affected by fungal species, CO2 level and N supply. Interactions between fungal species and CO2 were also regularly significant. At low N availability, elevated CO2 had the smallest impact on the photosynthetic performance of seedlings inoculated with H. cylindrosporum and the largest impact on seedlings with S. bovinus. At ambient CO2, increasing N supply had the smallest impact on seedlings inoculated with S. bovinus and the largest on seedlings inoculated with H. cylindrosporum. At low N availability, extraradical hyphal length increased after doubling CO2 level, but this was significant only for L. bicolor. At ambient CO2, increasing N levels reduced hyphal length for both H. cylindrosporum and S. bovinus, but not for L. bicolor. We discuss the potential interplay of two major elements of global change, elevated CO2 and increased N availability, and their effects on plant growth. We conclude that increased N supply potentially relieves mycorrhiza-induced progressive N limitation under elevated CO2
    Decomposition in tropical forests: a pan-tropical study of the effects of litter type, litter placement and mesofaunal exclusion across a rainfall gradient
    Powers, J.S. ; Montgomery, R.A. ; Adair, C. ; Brearley, F.Q. ; DeWalt, S.J. ; Poorter, L. - \ 2009
    Journal of Ecology 97 (2009)4. - ISSN 0022-0477 - p. 801 - 811.
    hawaiian montane forests - terrestrial ecosystems - leaf decomposition - rain-forest - root decomposition - plant litter - soil - climate - rates - quality
    1. Litter decomposition recycles nutrients and causes large fluxes of carbon dioxide into the atmosphere. It is typically assumed that climate, litter quality and decomposer communities determine litter decay rates, yet few comparative studies have examined their relative contributions in tropical forests. 2. We used a short-term litterbag experiment to quantify the effects of litter quality, placement and mesofaunal exclusion on decomposition in 23 tropical forests in 14 countries. Annual precipitation varied among sites (760¿5797 mm). At each site, two standard substrates (Raphia farinifera and Laurus nobilis) were decomposed in fine- and coarse-mesh litterbags both above and below ground for approximately 1 year. 3. Decomposition was rapid, with >95% mass loss within a year at most sites. Litter quality, placement and mesofaunal exclusion all independently affected decomposition, but the magnitude depended upon site. Both the average decomposition rate at each site and the ratio of above- to below-ground decay increased linearly with annual precipitation, explaining 60¿65% of among-site variation. Excluding mesofauna had the largest impact on decomposition, reducing decomposition rates by half on average, but the magnitude of decrease was largely independent of climate. This suggests that the decomposer community might play an important role in explaining patterns of decomposition among sites. Which litter type decomposed fastest varied by site, but was not related to climate. 4. Synthesis. A key goal of ecology is to identify general patterns across ecological communities, as well as relevant site-specific details to understand local dynamics. Our pan-tropical study shows that certain aspects of decomposition, including average decomposition rates and the ratio of above- to below-ground decomposition are highly correlated with a simple climatic index: mean annual precipitation. However, we found no relationship between precipitation and effects of mesofaunal exclusion or litter type, suggesting that site-specific details may also be required to understand how these factors affect decomposition at local scales
    Terrestrial water storage change from temporal gravity variation
    Hasan, S. - \ 2009
    Wageningen University. Promotor(en): P.A.A. Troch; Remko Uijlenhoet. - [S.l.] : S.n. - ISBN 9789085853855 - 83
    hydrologie - wateropslag - zwaartekracht - verandering - variatie in de tijd - terrestrische ecosystemen - zwaartekrachtgolven - hydrology - water storage - gravity - change - temporal variation - terrestrial ecosystems - atmospheric gravity waves
    Recent progress in accurately monitoring temporal gravity variations by means of superconducting gravimeters and satellite geodesy provides unprecedented opportunities in closing the water balance. This thesis deals with the relation between temporal gravity variation and water storage change
    Dissolved organic nitrogen: an overlooked Pathway of nitrogen loss from agricultural systems?
    Kessel, C. van; Clough, T. ; Groenigen, J.W. van - \ 2009
    Journal of Environmental Quality 38 (2009). - ISSN 0047-2425 - p. 393 - 401.
    soil biochemical attributes - sandy soil - terrestrial ecosystems - management-practices - seasonal trends - pastoral soils - water samples - amino-acids - new-zealand - land-use
    Received for publication June 18, 2008. Conventional wisdom postulates that leaching losses of N from agriculture systems are dominated by NO3¿. Although the export of dissolved organic nitrogen (DON) into the groundwater has been recognized for more than 100 yr, it is often ignored when total N budgets are constructed. Leaching of DON into stream and drinking water reservoirs leads to eutrophication and acidification, and can pose a potential risk to human health. The main objective of this review was to determine whether DON losses from agricultural systems are significant, and to what extent they pose a risk to human health and the environment. Dissolved organic N losses across agricultural systems varied widely with minimum losses of 0.3 kg DON ha¿1yr¿1 in a pasture to a maximum loss of 127 kg DON ha¿1yr¿1 in a grassland following the application of urine. The mean and median values for DON leaching losses were found to be 12.7 and 4.0 kg N ha¿1yr¿1, respectively. On average, DON losses accounted for 26% of the total soluble N (NO3¿ plus DON) losses, with a median value of 19%. With a few exceptions, DON concentrations exceeded the criteria recommendations for drinking water quality. The extent of DON losses increased with increasing precipitation/irrigation, higher total inputs of N, and increasing sand content. It is concluded that DON leaching can be an important N loss pathway from agricultural systems. Models used to simulate and predict N losses from agricultural systems should include DON losses.
    Increased Litter Build Up and Soil Organic Matter Stabilization in a Poplar Plantation After 6 Years of atmospheric CO2 Enrichment (FACE): Final Results of POP-EuroFace Compared to Other Forest FACE Experiments
    Hoosbeek, M.R. ; Scarascia-Mugnozza, G. - \ 2009
    Ecosystems 12 (2009)2. - ISSN 1432-9840 - p. 220 - 239.
    nitrogen-use efficiency - elevated co2 - carbon storage - mineral soil - terrestrial ecosystems - biomass production - cultivated soils - tropospheric o-3 - deciduous forest - n-fertilization
    Free air CO2 enrichment (FACE) experiments in aggrading temperate forests and plantations have been initiated to test whether temperate forest ecosystems act as sinks for anthropogenic emissions of CO2. These FACE experiments have demonstrated increases in net primary production and carbon (C) storage in forest vegetation due to increased atmospheric CO2 concentrations. However, the fate of this extra biomass in the forest floor or mineral soil is less clear. After 6 years of FACE treatment in a short-rotation poplar plantation, we observed an additional sink of 32 g C m¿2 y¿1 in the forest floor. Mineral soil C content increased equally under ambient and increased CO2 treatment during the 6-year experiment. However, during the first half of the experiment the increase in soil C was suppressed under FACE due to a priming effect, that is, the additional labile C increased the mineralization of older SOM, whereas during the second half of the experiment the increase in soil C was larger under FACE. An additional sink of 54 g C m¿2 y¿1 in the top 10 cm of the mineral soil was created under FACE during the second half of the experiment. Although, this FACE effect was not significant due to a combination of soil spatial variability and the low number of replicates that are inherent to the present generation of forest stand FACE experiments. Physical fractionation by wet sieving revealed an increase in the C and nitrogen (N) content of macro-aggregates due to FACE. Further fractionation by density showed that FACE increased C and N contents of the light iPOM and mineral associated intra-macro-aggregate fractions. Isolation of micro-aggregates from macro-aggregates and subsequent fractionation by density revealed that FACE increased C and N contents of the light iPOM, C content of the fine iPOM and C and N contents of the mineral associated intra-micro-aggregate fractions. From this we infer that the amount of stabilized C and N increased under FACE treatment. We compared our data with published results of other forest FACE experiments and infer that the type of vegetation and soil base saturation, as a proxy for bioturbation, are important factors related to the size of the additional C sinks of the forest floor¿soil system under FACE.
    Effect of nitrogen deposition reduction on biodiversity and carbon sequestration
    Wamelink, G.W.W. ; Dobben, H.F. van; Mol-Dijkstra, J.P. ; Schouwenberg, E.P.A.G. ; Kros, J. ; Vries, W. de; Berendse, F. - \ 2009
    Forest Ecology and Management 258 (2009)8. - ISSN 0378-1127 - p. 1774 - 1779.
    climate-change - terrestrial ecosystems - changing biodiversity - species-diversity - migration rates - plant diversity - elevated co2 - forest - impact - fertilization
    Global warming and loss of biodiversity are among the most prominent environmental issues of our time. Large sums are spent to reduce their causes, the emission of CO2 and nitrogen compounds. However, the results of such measures are potentially conflicting, as the reduction of nitrogen deposition may hamper carbon sequestration and thus increase global warming. Moreover, it is uncertain whether a lower nitrogen deposition will lead to a higher biodiversity. We applied a dynamic soil model, a vegetation dynamic model and a biodiversity regression model to investigate the effect of nitrogen deposition reduction on the carbon sequestration and plant species diversity. The soil and vegetation models simulate the carbon sequestration as a result of nitrogen deposition and they provide the biodiversity model with information on the soil conditions groundwater table, pH and nitrogen availability. The plant diversity index resulting from the biodiversity model is based on the occurrence of `red list¿ species for the tree soil conditions. Based on the model runs we forecast that a gradual decrease in nitrogen deposition from 40 to 10 kg N ha¿1 y¿1 in the next 25 years will cause a drop in the net carbon sequestration of forest in The Netherlands to 27% of the present amount, while biodiversity remains constant in forest, but may increase in heathland and grassland.
    The terrestrial carbon cycle on the regional and global scale : modeling, uncertainties and policy relevance
    Minnen, J.G. van - \ 2008
    Wageningen University. Promotor(en): Rik Leemans, co-promotor(en): R. Swart. - [S.l.] : S.n. - ISBN 9789085048107 - 237
    koolstofcyclus - klimaatverandering - landgebruik - beoordeling - milieubeleid - simulatiemodellen - biosfeer - terrestrische ecosystemen - carbon cycle - climatic change - land use - assessment - environmental policy - simulation models - biosphere - terrestrial ecosystems
    Contains the chapters: The importance of three centuries of climate and land-use change for the global and regional terrestrial carbon cycle; and The terrestrial C cycle and its role in the climate change policy
    Effecten van klimaatverandering op terrestrische ecosystemen
    Vos, Claire - \ 2007
    climatic change - effects - adaptation - adaptability - biodiversity - environmental factors - habitat fragmentation - terrestrial ecosystems
    Response of plant species richness and primary productivity in shrublands along a north-south gradient in Europe to seven years of experimental warming and drought: reductions in primary productivity in the heat and drought year of 2003
    Penuelas, J. ; Prieto, P. ; Beier, C. ; Cesaraccio, C. ; Angelis, P. de; Dato, G. de; Emmett, B.A. ; Estiarte, M. ; Garadnai, J. ; Gorissen, A. ; Lang, E.K. ; Kroel-Dulay, G. ; Llorens, L. ; Pellizzaro, G. ; Riis-Nielsen, T. ; Schmidt, I.K. ; Sirca, C. ; Sowerby, A. ; Spano, D. ; Tietema, A. - \ 2007
    Global Change Biology 13 (2007)12. - ISSN 1354-1013 - p. 2563 - 2581.
    evergreen mediterranean forest - climate-change - quercus-ilex - terrestrial ecosystems - environmental-change - phillyrea-latifolia - arctic ecosystems - cistus-albidus - carbon-cycle - soil
    We used a nonintrusive field experiment carried out at six sites - Wales (UK), Denmark (DK), the Netherlands (NL), Hungary (HU), Sardinia (Italy - IT), and Catalonia (Spain - SP) - along a climatic and latitudinal gradient to examine the response of plant species richness and primary productivity to warming and drought in shrubland ecosystems. The warming treatment raised the plot daily temperature by ca. 1 degrees C, while the drought treatment led to a reduction in soil moisture at the peak of the growing season that ranged from 26% at the SP site to 82% in the NL site. During the 7 years the experiment lasted (1999-2005), we used the pin-point method to measure the species composition of plant communities and plant biomass, litterfall, and shoot growth of the dominant plant species at each site. A significantly lower increase in the number of species pin-pointed per transect was found in the drought plots at the SP site, where the plant community was still in a process of recovering from a forest fire in 1994. No changes in species richness were found at the other sites, which were at a more mature and stable state of succession and, thus less liable to recruitment of new species. The relationship between annual biomass accumulation and temperature of the growing season was positive at the coldest site and negative at the warmest site. The warming treatment tended to increase the aboveground net primary productivity (ANPP) at the northern sites. The relationship between annual biomass accumulation and soil moisture during the growing season was not significant at the wettest sites, but was positive at the driest sites. The drought treatment tended to reduce the ANPP in the NL, HU, IT, and SP sites. The responses to warming were very strongly related to the Gaussen aridity index (stronger responses the lower the aridity), whereas the responses to drought were not. Changes in the annual aboveground biomass accumulation, litterfall, and, thus, the ANPP, mirrored the interannual variation in climate conditions: the most outstanding change was a decrease in biomass accumulation and an increase in litterfall at most sites during the abnormally hot year of 2003. Species richness also tended to decrease in 2003 at all sites except the cold and wet UK site. Species-specific responses to warming were found in shoot growth: at the SP site, Globularia alypum was not affected, while the other dominant species, Erica multiflora, grew 30% more; at the UK site, Calluna vulgaris tended to grow more in the warming plots, while Empetrum nigrum tended to grow less. Drought treatment decreased plant growth in several studied species, although there were some species such as Pinus halepensis at the SP site or C. vulgaris at the UK site that were not affected. The magnitude of responses to warming and drought thus depended greatly on the differences between sites, years, and species and these multiple plant responses may be expected to have consequences at ecosystem and community level. Decreases in biodiversity and the increase in E. multiflora growth at the SP site as a response to warming challenge the assumption that sensitivity to warming may be less well developed at more southerly latitudes; likewise, the fact that one of the studied shrublands presented negative ANPP as a response to the 2003 heat wave also challenges the hypothesis that future climate warming will lead to an enhancement of plant growth and carbon sequestration in temperate ecosystems. Extreme events may thus change the general trend of increased productivity in response to warming n the colder sites.
    Indicators for the 'Convention on biodiversity 2010". Influence of climate change on biodiversity
    Nijhof, B.S.J. ; Vos, C.C. ; Strien, A.J. van - \ 2007
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 53.7a) - 44
    biodiversiteit - indicatorsoorten - klimaatverandering - fenologie - biodiversiteitsbepaling - terrestrische ecosystemen - biologische monitoring - biodiversity - indicator species - climatic change - phenology - biodiversity assessment - terrestrial ecosystems - biomonitoring
    This report takes the first steps for the development of a climate change indicator system, based on the different responses of species to climate change. The usefulness of several climate change indicators is tested, by analyzing the relation between indicators and population trends of target species. The study is restricted to terrestrial ecosystems. Also a reference list for cold, warmth and neutral preferent indicator groups is provided. An inventory of CBS and Alterra
    Microbial ecology of biological invasions
    Putten, W.H. van der; Klironomos, J.N. ; Wardle, D.A. - \ 2007
    ISME Journal 1 (2007). - ISSN 1751-7362 - p. 28 - 37.
    exotic plant invasions - arbuscular mycorrhizal fungi - below-ground biodiversity - soil-borne fungi - ammophila-arenaria - terrestrial ecosystems - decomposition rate - leaf-litter - phytophthora-cinnamomi - community structure
    Invasive microbes, plants and animals are a major threat to the composition and functioning of ecosystems; however, the mechanistic basis of why exotic species can be so abundant and disruptive is not well understood. Most studies have focused on invasive plants and animals, although few have considered the effects of invasive microbes, or interactions of invasive plant and animal species with microbial communities. Here, we review effects of invasive plants on soil microbial communities and discuss consequences for plant performance, plant community structure and ecosystem processes. In addition, we briefly discuss effects of invasive soil microbes on plant communities, which has been less well studied, and effects of invasive animals on soil decomposers and ecosystem functioning. We do this by considering each of three important functional groups of microbes, namely soil microbial parasites and pathogens, mutualistic symbionts and decomposers. We conclude that invasive plants, pathogenic and symbiotic soil microbes will have strongest effects on the abundance of individual species, community diversity and ecosystem functioning. Invasive decomposer microbes probably have little impact, because of limited specificity and great functional redundancy. However, invasive plants and animals can have major effects on microbial decomposition in soil. We propose that understanding, predicting and counteracting consequences of enhanced global homogenization of natural communities through introducing exotic plants, animals and microbes will require future studies on how pathogenic, symbiotic and decomposer soil microbes interact, how they are influenced by higher trophic level organisms and how their combined effects are influencing the composition and functioning of ecosystems.
    Soil and vegetation nutrient response to bison carcasses in Bialowieza Primeval Forest, Poland
    Melis, C. ; Selva, N. ; Teurlings, I.J.M. ; Skarpe, C. ; Linnell, J.D.C. ; Andersen, R. - \ 2007
    Ecological Research 22 (2007)5. - ISSN 0912-3814 - p. 807 - 813.
    terrestrial ecosystems - herbivores - scavengers - energy
    Ungulate carcasses can have important effects on the surrounding soil and vegetation. The impact of six carcasses of European bison (Bison bonasus) was investigated for the first time in a natural temperate forest (Bialeowieza, Poland) by measuring soil and plant nutrient concentrations along a gradient extending from the centre of each carcass. Calcium concentration and pH were found to be higher at the centre of the carcass, decreasing towards the periphery. This effect lasted up to 7 years after the death of the animal. The concentration of most nutrients in the soil and plants varied irregularly, suggesting an effect of the carcass at its centre but the absence of a clear pattern of variation along the gradient. Concentrations of NO3- in the soil differed only at the 1-year old carcass, suggesting a fast turnover of nitrate in temperate forests. Our results show that the effects of large herbivore carcasses on soil and plant nutrient concentrations are not easily detectable in a temperate forest as in more homogeneous habitats, such as tundra and prairie. This may be due to the high activity of scavengers and nutrient recycling in the study area, but it may also be a consequence of a more complex and patchy interaction between nutrient availability and other limiting factors in temperate forests.
    Indicators for the 'Convention on biodiversity 2010'. National Capital Index version 2.0 : 1. Trends in extent of selected biomes, ecosystems and habitats : 2. Trends in abundance and distribution of selected species : fact sheet
    Reijnen, M.J.S.M. - \ 2007
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 53.1) - 20
    biodiversiteit - ecosystemen - degradatie - milieuafbraak - indicatorsoorten - soorten - soortenrijkdom - habitats - aquatische ecosystemen - terrestrische ecosystemen - natuur - biodiversity - ecosystems - degradation - environmental degradation - indicator species - species - species richness - habitats - aquatic ecosystems - terrestrial ecosystems - nature
    Photosynthesis drives anomalies in net carbon-exchange of pine forests at different latitudes
    Luyssaert, S. ; Janssens, I.A. ; Sulkava, M. ; Papale, D. ; Dolman, A.J. ; Reichstein, M. ; Hollmén, J. ; Martin, J.G. ; Suni, T. ; Vesala, T. ; Loustau, D. ; Law, B.E. ; Moors, E.J. - \ 2007
    Global Change Biology 13 (2007)10. - ISSN 1354-1013 - p. 2110 - 2127.
    netto ecosysteem uitwisseling - kooldioxide - fotosynthese - dennen - bossen - klimaatfactoren - net ecosystem exchange - carbon dioxide - photosynthesis - pines - forests - climatic factors - interannual climate variability - eddy covariance technique - boreal forest - ecosystem respiration - european forests - atmospheric co2 - temperature variability - terrestrial ecosystems - tree photosynthesis - soil respiration
    The growth rate of atmospheric CO2 exhibits large temporal variation that is largely determined by year-to-year fluctuations in land¿atmosphere CO2 fluxes. This land¿atmosphere CO2-flux is driven by large-scale biomass burning and variation in net ecosystem exchange (NEE). Between- and within years, NEE varies due to fluctuations in climate. Studies on climatic influences on inter- and intra-annual variability in gross photosynthesis (GPP) and net carbon uptake in terrestrial ecosystems have shown conflicting results. These conflicts are in part related to differences in methodology and in part to the limited duration of some studies. Here, we introduce an observation-driven methodology that provides insight into the dependence of anomalies in CO2 fluxes on climatic conditions. The methodology was applied on fluxes from a boreal and two temperate pine forests. Annual anomalies in NEE were dominated by anomalies in GPP, which in turn were correlated with incident radiation and vapor pressure deficit (VPD). At all three sites positive anomalies in NEE (a reduced uptake or a stronger source than the daily sites specific long-term average) were observed on summer days characterized by low incident radiation, low VPD and high precipitation. Negative anomalies in NEE occurred mainly on summer days characterized by blue skies and mild temperatures. Our study clearly highlighted the need to use weather patterns rather than single climatic variables to understand anomalous CO2 fluxes. Temperature generally showed little direct effect on anomalies in NEE but became important when the mean daily air temperature exceeded 23 °C. On such days GPP decreased likely because VPD exceeded 2.0 kPa, inhibiting photosynthetic uptake. However, while GPP decreased, the high temperature stimulated respiration, resulting in positive anomalies in NEE. Climatic extremes in summer were more frequent and severe in the South than in the North, and had larger effects in the South because the criteria to inhibit photosynthesis are more often met.
    Above- and belowground insect herbivores differentially affect soil nematode communities in species-rich plant communities
    Deyn, G.B. de; Ruijven, J. van; Raaijmakers, C.E. ; Ruiter, P.C. de; Putten, W.H. van der - \ 2007
    Oikos 116 (2007)6. - ISSN 0030-1299 - p. 923 - 930.
    trophic-level biomasses - food-web - entomopathogenic nematodes - terrestrial ecosystems - microbial community - steinernema-feltiae - grassland - diversity - dynamics - biodiversity
    Interactions between above- and belowground invertebrate herbivores alter plant diversity, however, little is known on how these effects may influence higher trophic level organisms belowground. Here we explore whether above- and belowground invertebrate herbivores which alter plant community diversity and biomass, in turn affect soil nematode communities. We test the hypotheses that insect herbivores 1) alter soil nematode diversity, 2) stimulate bacterial-feeding and 3) reduce plant-feeding nematode abundances. In a full factorial outdoor mesocosm experiment we introduced grasshoppers (aboveground herbivores), wireworms (belowground herbivores) and a diverse soil nematode community to species-rich model plant communities. After two years, insect herbivore effects on nematode diversity and on abundance of herbivorous, bacterivorous, fungivorous and omni-carnivorous nematodes were evaluated in relation to plant community composition. Wireworms did not affect nematode diversity despite enhanced plant diversity, while grasshoppers, which did not affect plant diversity, reduced nematode diversity. Although grasshoppers and wireworms caused contrasting shifts in plant species dominance, they did not affect abundances of decomposer nematodes at any trophic level. Primary consumer nematodes were, however, strongly promoted by wireworms, while community root biomass was not altered by the insect herbivores. Overall, interaction effects of wireworms and grasshoppers on the soil nematodes were not observed, and we found no support for bottom-up control of the nematodes. However, our results show that above- and belowground insect herbivores may facilitate root-feeding rather than decomposer nematodes and that this facilitation appears to be driven by shifts in plant species composition. Moreover, the addition of nematodes strongly suppressed shoot biomass of several forb species and reduced grasshopper abundance. Thus, our results suggest that nematode feedback effects on plant community composition, due to plant and herbivore parasitism, may strongly depend on the presence of insect herbivores
    Time horizon dependent characterization factors for acidification in life-cycle assessment based on forest plant species occurrence in Europe
    Zelm, R. van; Huijbregts, M.J.A. ; Jaarsveld, H.A. van; Reinds, G.J. ; Zwart, D. de; Struijs, J. ; Meent, D. van de - \ 2007
    Environmental Science and Technology 41 (2007)3. - ISSN 0013-936X - p. 922 - 927.
    terrestrial ecosystems - impact assessment - acid deposition - pollutants - soil - transport
    This paper describes a new approach in life-cycle impact assessment to derive characterization factors for acidification in European forests. Time horizon dependent characterization factors for acidification were calculated, whereas before only steady-state factors were available. The characterization factors indicate the change in the potential occurrence of plant species due to a change in emission, and they consist of a fate and an effect factor. The fate factor combines the results of an atmospheric deposition model and a dynamic soil acidification model. The change in base saturation in soil due to an atmospheric emission change was derived for 20, 50, 100, and 500 year time horizons. The effect factor was based on a dose-response curve of the potential occurrence of plant species, derived from multiple regression equations per plant species. The results showed that characterization factors for acidification increase up to a factor of 13 from a 20 years to a 500 years time horizon. Characterization factors for ammonia are 4.0-4.3 times greater than those for nitrogen oxides (NOx), and characterization factors for sulfur dioxide are 1.4-2.0 times greater than those for NOx. Aggregation of damage due to acidification with other impact categories on the European scale becomes feasible with the applied approach.
    Linking soil C and N dynamics in managed ecosystem under elevated CO2
    Groenigen, C.J. van - \ 2007
    Wageningen University. Promotor(en): N. van Breemen; C. van Kessel, co-promotor(en): Peter Kuikman; J. Six. - [S.l.] : S.n. - ISBN 9789085046264 - 141
    bodemchemie - nitraten - koolstof - kooldioxide - voedingsstoffenbeschikbaarheid - ecosystemen - terrestrische ecosystemen - soil chemistry - nitrates - carbon - carbon dioxide - nutrient availability - ecosystems - terrestrial ecosystems
    Door fossiele brandstof te gebruiken, bos te kappen en grond te bewerken voor landbouw doet de mensheid de concentratie van CO2 in de atmosfeer stijgen. Het is onduidelijk of en hoeveel C hierdoor in de bodem kan worden vastgelegd. Aan de ene kant hebben talloze studies aangetoond dat een hogere CO2 concentratie de groei van planten en daarmee de toevoer van C naar de bodem stimuleert. Aan de andere kant kunnen planten in een wereld met meer CO2 in de atmosfeer alleen harder groeien als de bodem hen van voldoende nutriënten voorziet. De onzekerheid over het effect van de beschikbaarheid aan nutriënten zorgt voor grote verschillen in schattingen naar toekomstige koolstofopslag in bodem en vegetatie. Met dit onderzoek is geprobeerd te bepalen hoe onder verhoogde CO2 concentraties de beschikbaarheid van nutriënten de kringloop van C in bodems beïnvloedt.
    Determinants of terrestrial ecosystem carbon balance inferred from European eddy covariance flux sites
    Reichstein, M. ; Papale, D. ; Valentini, R. ; Aubinet, M. ; Bernhofer, C. ; Knohl, A. ; Laurila, T. ; Lindroth, A. ; Moors, E.J. ; Pilegaard, K. ; Seufert, G. - \ 2007
    Geophysical Research Letters 34 (2007). - ISSN 0094-8276 - 5
    netto ecosysteem koolstofbalans - eddy-covariantie - primaire productie - koolstofcyclus - terrestrische ecosystemen - net ecosystem carbon balance - eddy covariance - primary production - carbon cycle - terrestrial ecosystems - spatial variability - water-vapor - respiration - exchange - forests - climate - productivity - temperature - vegetation - dioxide
    Pioneering work in the last century has resulted in a widely accepted paradigm that primary production is strongly positively related to temperature and water availability such that the northern hemispheric forest carbon sink may increase under conditions of global warming. However, the terrestrial carbon sink at the ecosystem level (i.e. net ecosystem productivity, NEP) depends on the net balance between gross primary productivity (GPP) and ecosystem respiration (TER). Through an analysis of European eddy covariance flux data sets, we find that the common climate relationships for primary production do not hold for NEP. This is explained by the fact that decreases in GPP are largely compensated by parallel decreases in TER when climatic factors become more limiting. Moreover, we found overall that water availability was a significant modulator of NEP, while the multivariate effect of mean annual temperature is small and not significant. These results indicate that climate- and particularly temperature-based projections of net carbon balance may be misleading. Future research should focus on interactions between the water and carbon cycles and the effects of disturbances on the carbon balance of terrestrial ecosystems.
    Water use strategies and ecosystem-atmosphere exchange of CO2 in two highly seasonal environments
    Arneth, A. ; Veenendaal, E.M. ; Best, C. ; Timmermans, W. ; Kolle, O. ; Montagnani, L. ; Shibistova, O. - \ 2006
    Biogeosciences 3 (2006)4. - ISSN 1726-4170 - p. 421 - 437.
    siberian pine forest - carbon-dioxide - interannual variability - terrestrial ecosystems - vegetation dynamics - climate-change - model - respiration - fluxes - energy
    We compare assimilation and respiration rates, and water use strategies in four divergent ecosystems located in cold-continental central Siberia and in semi-arid southern Africa. These seemingly unrelated systems have in common a harsh and highly seasonal environment with a very sharp transition between the dormant and the active season, with vegetation facing dry air and soil conditions for at least part of the year. Moreover, the northern high latitudes and the semi-arid tropics will likely experience changes in key environmental parameters (e.g., air temperature and precipitation) in the future; indeed, in some regions marked climate trends have already been observed over the last decade or so.
    Kings without crowns: Analysis of abundance bacilli in different soil ecosystems
    Tzeneva, V.A. - \ 2006
    Wageningen University. Promotor(en): Willem de Vos, co-promotor(en): Hauke Smidt; A.D.L. Akkermans. - [S.l.] : S.n. - ISBN 9789090209890 - 187
    ecosystemen - bacillus - bodembacteriën - biodiversiteit - old fields - terrestrische ecosystemen - genexpressieanalyse - ecosystems - bacillus - soil bacteria - biodiversity - old fields - terrestrial ecosystems - genomics

    This study describes culture-dependent as well as culture-independent strategies to monitor diversity and abundance of Bacillus benzoevorans-related soil bacteria. These bacteria are wide spread around the world, inhabiting a variety of terrestrial environments. A distinguishing feature of the family Bacillaceae is their ability to form endospores. This capacity makes the genus Bacillus amenable to retrospective and biogeographical studies, as their endospores provide the means for survival under environmental conditions of stress, allowing their detection later on. For the rapid detection of B. benzoevorans-re\aiea populations in soil samples selective cultivation media and group-specific primers and probes were developed. Using these techniques the global distribution of this group was demonstrated and indicated their adaptive capacity to diverse soil ecosystems. A unique soil sample archive provided insight in the microbiological impact of land reclamation and flooding. Using multivariate statistical approaches were used to assess the microbial community dynamics over time and in response to the changing environmental conditions.

    Found in a variety of soil ecosystems, microorganisms related to B. benzoevorans seem to be able to populate a broad range of niches, which indicates a high degree of metabolic versatility and strong adaptive capability. Moreover, they account for a significant part of the total bacterial community (up to 30 %). Based on our exploratory study the importance of their role is just indicated, but not acknowledged yet. Therefore, it is proposed to regard B. benzoevorans relatives as 'kings without crowns'; as this group of bacteria deserves more scientific attention in future studies aiming to unravel their eco-physiology and functionality as major players of the soil microbiota.

    Overestimated biomass carbon pools of the northern mid- and high latitude forests
    Fang Jingyun, ; Brown, S. ; Tang Yanhong, ; Nabuurs, G.J. ; Wang Xiangping, ; Shen Haihua, - \ 2006
    Climatic Change 74 (2006)1-3. - ISSN 0165-0009 - p. 355 - 368.
    inventory data - united-states - terrestrial ecosystems - russian forests - woody biomass - us forests - sink - storage - china - vegetation
    The biomass carbon (C) stock of forests is one of key parameters for the study of regional and global carbon cycles. Literature reviews shows that inventory-based forest C stocks documented for major countries in the middle and high northern latitudes fall within a narrow range of 36-56 Mg C ha(-1) with an overall area-weighted mean of 43.6 Mg C ha(-1). These estimates are 0.40 to 0.71 times smaller than those (61-108 Mg C ha(-1)) used in previous analysis of balancing the global carbon budget. A statistical analysis, using the global forest biomass database, implies that aboveground biomass per hectare is proportional to forest mean height [biomass in Mg/ha = 10.63 (height in m)] in closed-canopy forests in the study regions, indicating that forest height can be a proxy of regional biomass C stocks. The narrow range of C stocks is likely a result of similar forest height across the northern regions. The lower biomass C stock obtained in this study strongly suggests that the role of the northern forests in the global carbon cycle needs to be re-evaluated. Our findings also suggest that regional estimates of biomass could be readily made from the use of satellite methods such as lidar that can measure forest canopy height over large regions.
    The impact of nitrogen deposition on carbon sequestration in European forests and forest soils
    Vries, W. de; Reinds, G.J. ; Gundersen, P. ; Sterba, H. - \ 2006
    Global Change Biology 12 (2006)7. - ISSN 1354-1013 - p. 1151 - 1173.
    terrestrial ecosystems - spatial-distribution - temperate forests - hardwood forest - climate-change - n-deposition - nitrate - sink - denitrification - co2
    An estimate of net carbon (C) pool changes and long-term C sequestration in trees and soils was made at more than 100 intensively monitored forest plots (level II plots) and scaled up to Europe based on data for more than 6000 forested plots in a systematic 16 km x 16 km grid (level I plots). C pool changes in trees at the level II plots were based on repeated forest growth surveys At the level I plots, an estimate of the mean annual C pool changes was derived from stand age and available site quality characteristics. C sequestration, being equal to the long-term C pool changes accounting for CO2 emissions because of harvest and forest fires, was assumed 33% of the overall C pool changes by growth. C sequestration in the soil were based on calculated nitrogen (N) retention (N deposition minus net N uptake minus N leaching) rates in soils, multiplied by the C/N ratio of the forest soils, using measured data only (level II plots) or a combination of measurements and model calculations (level I plots). Net C sequestration by forests in Europe (both trees and soil) was estimated at 0.117 Gton yr(-1), with the C sequestration in stem wood being approximately four times as high (0.094 Gton yr(-1)) as the C sequestration in the soil (0.023 Gton yr(-1)). The European average impact of an additional N input on the net C sequestration was estimated at approximately 25 kg C kg(-1) N for both tree wood and soil. The contribution of an average additional N deposition on European forests of 2.8 kg ha(-1) yr(-1) in the period 1960-2000 was estimated at 0.0118 Gton yr(-1), being equal to 10% of the net C sequestration in both trees and soil in that period (0.117 Gton yr(-1)). The C sequestration in trees increased from Northern to Central Europe, whereas the C sequestration in soil was high in Central Europe and low in Northern and Southern Europe. The result of this study implies that the impact of forest management on tree growth is most important in explaining the C pool changes in European forests.
    Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts
    Phoenix, G.K. ; Hicks, W.K. ; Cinderby, S. ; Kuylenstierna, J.C.I. ; Stock, W.D. ; Dentener, F.J. ; Giller, K.E. ; Austin, A.T. ; Lefroy, R.D.B. ; Gimeno, B.S. ; Ashmore, M.R. ; Ineson, P. - \ 2006
    Global Change Biology 12 (2006)3. - ISSN 1354-1013 - p. 470 - 476.
    terrestrial ecosystems - species richness - chalk-grassland - consequences - ecoregions - pollutants - population - vegetation - scenarios - ammonia
    Increased atmospheric nitrogen (N) deposition is known to reduce plant diversity in natural and semi-natural ecosystems, yet our understanding of these impacts comes almost entirely from studies in northern Europe and North America. Currently, we lack an understanding of the threat of N deposition to biodiversity at the global scale. In particular, rates of N deposition within the newly defined 34 world biodiversity hotspots, to which 50% of the world's floristic diversity is restricted, has not been quantified previously. Using output from global chemistry transport models, here we provide the first estimates of recent (mid-1990s) and future (2050) rates and distributions of N deposition within biodiversity hotspots. Our analysis shows that the average deposition rate across these areas was 50% greater than the global terrestrial average in the mid-1990s and could more than double by 2050, with 33 of 34 hotspots receiving greater N deposition in 2050 compared with 1990. By this time, 17 hotspots could have between 10% and 100% of their area receiving greater than 15 kg N ha1 yr1, a rate exceeding critical loads set for many sensitive European ecosystems. Average deposition in four hotspots is predicted to be greater than 20 kg N ha1 yr1. This elevated N deposition within areas of high plant diversity and endemism may exacerbate significantly the global threat of N deposition to world floristic diversity. Overall, we highlight the need for a greater global approach to assessing the impacts of N deposition
    Extreme climatic events shape arid and semiarid ecosystems
    Holmgren, M. ; Stapp, P. ; Dickman, C. ; Gracia, C. ; Graham, S. - \ 2006
    Frontiers in Ecology and the Environment 4 (2006)2. - ISSN 1540-9295 - p. 87 - 95.
    nino-southern oscillation - el-nino - long-term - population-dynamics - terrestrial ecosystems - functional-response - rodent populations - density-dependence - mammal assemblage - central australia
    Climatic changes associated with the El Nino Southern Oscillation (ENSO) can have a dramatic impact on terrestrial ecosystems worldwide, but especially on arid and semiarid systems, where productivity is strongly limited by precipitation. Nearly two decades of research, including both short-term experiments and long-term studies conducted on three continents, reveal that the initial, extraordinary increases in primary productivity percolate up through entire food webs, attenuating the relative importance of top-down control by predators, providing key resources that are stored to fuel future production, and altering disturbance regimes for months or years after ENSO conditions have passed. Moreover, the ecological changes associated with ENSO events have important implications for agroecosystems, ecosystem restoration, wildlife conservation, and the spread of disease. Here we present the main ideas and results of a recent symposium on the effects of ENSO in dry ecosystems, which was convened as part of the First Alexander von Humboldt International Conference on the El Nino Phenomenon and its Global Impact.
    The Dutch N-cascade in the European perspective
    Erisman, J.W. ; Domburg, N. ; Vries, W. de; Kros, H. ; Haan, B. de; Sanders, K. - \ 2005
    Science in China Series C-Life Sciences 48 (2005)Spec Issue. - ISSN 1006-9305 - p. 827 - 842.
    global nitrogen-cycle - terrestrial ecosystems - deposition - netherlands - consequences - forest - soils - fluxes - sinks - fate
    The Netherlands is "well known" for its nitrogen problems; it has one of the highest reactive nitrogen (Nr) emission densities in the world. It is a small country at the delta of several large European rivers. Ever since the industrial revolution, there has been a growing excess of nutrients and related emissions into the atmosphere (ammonia, nitrogen oxides and nitrous oxide) and into groundwater and surface water (nitrate), leading to a large range of cascading environmental impacts. Vehicular traffic, sewage and animal husbandry are the main sources of oxidized and reduced forms of Nr. This paper provides an overview of the origin and fate of nitrogen in the Netherlands, the various reported impacts of nitrogen, the Dutch and European policies to reduce nitrogen emissions and related impacts. In addition, ways are presented to go forward to potentially solve the problems in a European perspective. Solutions include the improvement of nitrogen efficiencies in different systems, technological options and education.
    Synergy between small- and large-scale feedbacks of vegetation on the water cycle
    Scheffer, M. ; Holmgren, M. ; Brovkin, V. ; Claussen, M. - \ 2005
    Global Change Biology 11 (2005)7. - ISSN 1354-1013 - p. 1003 - 1012.
    semiarid grazing systems - african humid period - tropical deforestation - arid ecosystems - climate system - terrestrial ecosystems - catastrophic shifts - arabian peninsula - northern africa - range condition
    Predictions of the effects of climate change on the extent of forests, savannas and deserts are usually based on simple response models derived from actual vegetation distributions. In this review, we show two major problems with the implicitly assumed straightforward cause-effect relationship. Firstly, several studies suggest that vegetation itself may have considerable effects on regional climate implying a positive feedback, which can potentially lead to large-scale hysteresis. Secondly, vegetation ecologists have found that effects of plants on microclimate and soils can cause a microscale positive feedback, implying that critical precipitation conditions for colonization of a site may differ from those for disappearance from that site. We argue that it is important to integrate these nonlinearities at disparate scales in models to produce more realistic predictions of potential effects of climate change and deforestation.
    Calculation of critical loads for cadmium, lead and mercury; background document to a mapping manual on critical loads of cadmium, lead and mercury
    Vries, W. de; Schütze, G. ; Lofts, S. ; Tipping, E. ; Meili, M. ; Römkens, P.F.A.M. ; Groenenberg, J.E. - \ 2005
    Wageningen : Alterra (Alterra-report 1104) - 143
    cadmium - lood - kwik - zware metalen - uitspoelen - ecosystemen - methodologie - oppervlaktewater - bodemoplossing - terrestrische ecosystemen - aquatische ecosystemen - ecotoxicologie - cadmium - lead - mercury - heavy metals - leaching - ecosystems - methodology - surface water - soil solution - terrestrial ecosystems - aquatic ecosystems - ecotoxicology
    This report on heavy metals provides up-to-date methodologies to derive critical loads for the heavy metals cadmium (Cd), lead (Pb) and mercury (Hg) for both terrestrial and aquatic ecosystems. It presents background information to a Manual on Critical Loads for those metals. Focus is given to the methodologies and critical limits that have to be used to derive critical loads can be derived for Cd, Pb and Hg in view of : (i) ecotoxicological effects for either terrestrial or aquatic ecosystems.and (ii) human health effects for either terrestrial or aquatic ecosystems. For Hg, a separate approach is described to estimate critical levels in precipitation in view of human health effects due to the consumption of fish. The limitations and uncertainties of the approach are discussed including: (i) the uncertainties and particularities of the steady-state models used and (ii) the reliability of the approaches that are applied to derive critical limits for critical total dissolved metal concentrations in soil solution and surface water
    Nonintrusive Field Experiments Show Different Plant Responses to Warming and Drought Among Sites, Seasons, and Species in a North-South European Gradient
    Peñuelas, J. ; Gordon, C. ; Llorens, L. ; Nielsen, T. ; Tietema, A. ; Beier, J.C. ; Bruna, P. ; Emmett, B. ; Estiarte, M. ; Gorissen, A. - \ 2004
    Ecosystems 7 (2004)6. - ISSN 1432-9840 - p. 598 - 612.
    terrestrial ecosystems - environmental-change - cistus-albidus - climate-change - temperature - nutrient - quercus - tundra - winter - life
    We used a novel, nonintrusive experimental system to examine plant responses to warming and drought across a climatic and geographical latitudinal gradient of shrubland ecosystems in four sites from northern to southern Europe (UK, Denmark, The Netherlands, and Spain). In the first two years of experimentation reported here, we measured plant cover and biomass by the pinpoint method, plant 14C uptake, stem and shoot growth, flowering, leaf chemical concentration, litterfall, and herbivory damage in the dominant plant species of each site. The two years of approximately 1°C experimental warming induced a 15% increase in total aboveground plant biomass growth in the UK site. Both direct and indirect effects of warming, such as longer growth season and increased nutrient availability, are likely to be particularly important in this and the other northern sites which tend to be temperature-limited. In the water-stressed southern site, there was no increase in total aboveground plant biomass growth as expected since warming increases water loss, and temperatures in those ecosystems are already close to the optimum for photosynthesis. The southern site presented instead the most negative response to the drought treatment consisting of a soil moisture reduction at the peak of the growing season ranging from 33% in the Spanish site to 82% in The Netherlands site. In the Spanish site there was a 14% decrease in total aboveground plant biomass growth relative to control. Flowering was decreased by drought (up to 24% in the UK and 40% in Spain). Warming and drought decreased litterfall in The Netherlands site (33% and 37%, respectively) but did not affect it in the Spanish site. The tissue P concentrations generally decreased and the N/P ratio increased with warming and drought except in the UK site, indicating a progressive importance of P limitation as a consequence of warming and drought. The magnitude of the response to warming and drought was thus very sensitive to differences among sites (cold-wet northern sites were more sensitive to warming and the warm-dry southern site was more sensitive to drought), seasons (plant processes were more sensitive to warming during the winter than during the summer), and species. As a result of these multiple plant responses, ecosystem and community level consequences may be expected.
    Vegetation, water, humans and the climate; a new perspective on an interactive system
    Kabat, P. ; Claussen, M. ; Dirmeyer, P.A. ; Gash, J.H.C. ; Bravo de Guenni, L. ; Meybeck, M. ; Pielke sr., R.A. ; Vörösmarty, C.J. ; Hutjes, R.W.A. ; Lütkemeier, S. - \ 2004
    Berlin (Germany) [etc.] : Springer (Global change : the IGBP series ) - ISBN 9783540424000 - 566
    geologie - hydrologie - klimaat - bodem - vegetatie - menselijke activiteit - milieutoets - interacties - aardwetenschappen - terrestrische ecosystemen - hydrologische cyclus - biosfeer - geology - hydrology - climate - soil - vegetation - human activity - environmental assessment - interactions - earth sciences - terrestrial ecosystems - hydrological cycle - biosphere
    Plant species identity and diversity effects on different trophic levels of nematodes in the soil food web
    Deyn, G.B. de; Raaijmakers, C.E. ; Ruijven, J. van; Berendse, F. ; Putten, W.H. van der - \ 2004
    Oikos 106 (2004)3. - ISSN 0030-1299 - p. 576 - 586.
    below-ground biodiversity - arthropod diversity - microbial biomass - terrestrial ecosystems - grassland ecosystems - community structure - natural vegetation - experimental tests - productivity - succession
    Previous studies on biodiversity and soil food web composition have mentioned plant species identity, as well as plant species diversity as the main factors affecting the abundance and diversity of soil organisms. However, most studies have been carried out under limitations of time, space, or appropriate controls. In order to further examine the relation between plant species diversity and the soil food web, we conducted a three-year semi-field experiment in which eight plant species (4 forb and 4 grass species) were grown in monocultures and mixtures of two, four and eight plant species. In addition there were communities with 16 plant species. We analyzed the abundance and identity of the nematodes in soil and roots, including feeding groups from various trophic levels (primary and secondary consumers, carnivores, and omnivores) in the soil food web.

    Plant species diversity and plant identity affected the diversity of nematodes. The effect of plant diversity was attributed to the complementarity in resource quality of the component plant species rather than to an increase in total resource quantity. The nematode diversity varied more between the different plant species than between different levels of plant species diversity, so that plant identity is more important than plant diversity. Nevertheless the nematode diversity in plant mixtures was higher than in any of the plant monocultures, due to the reduced dominance of the most abundant nematode taxa in the mixed plant communities. Plant species identity affected the abundances of the lower trophic consumer levels more than the higher trophic levels of nematodes. Plant species diversity and plant biomass did not affect nematode abundance. Our results, therefore, support the hypothesis that resource quality is more important than resource quantity for the diversity of soil food web components and that plant species identity is more important than plant diversity per se.
    More new carbon in the mineral soil of a poplar plantation under Free Air Carbon Erichment (POPFACE): Cause of increased priming effect?
    Hoosbeek, M.R. ; Lukac, M. ; Dam, D. ; Godbold, D. ; Velthorst, E.J. ; Bondi, F.A. ; Peressotti, A. ; Cotrufo, M.F. ; Angelis, P. de; Scarascia-Mugnozza, G. - \ 2004
    Global Biogeochemical Cycles 18 (2004)1. - ISSN 0886-6236 - 7 p.
    elevated atmospheric co2 - organic-matter - terrestrial ecosystems - turnover - forest - storage - system - decomposition - mechanisms - feedbacks
    [1] In order to establish suitability of forest ecosystems for long-term storage of C, it is necessary to characterize the effects of predicted increased atmospheric CO2 levels on the pools and fluxes of C within these systems. Since most C held in terrestrial ecosystems is in the soil, we assessed the influence of Free Air Carbon Enrichment (FACE) treatment on the total soil C content (C-total) and incorporation of litter derived C (C-new) into soil organic matter (SOM) in a fast growing poplar plantation. C-new was estimated by the C3/C4 stable isotope method. C-total contents increased under control and FACE respectively by 12 and 3%, i.e., 484 and 107 gC/m(2), while 704 and 926 gC/m(2) of new carbon was sequestered under control and FACE during the experiment. We conclude that FACE suppressed the increase of C-total and simultaneously increased C-new. We hypothesize that these opposite effects may be caused by a priming effect of the newly incorporated litter, where priming effect is defined as the stimulation of SOM decomposition caused by the addition of labile substrates.
    Long-term ecosystem level experiments at Toolik Lake, Alaska, and at Abisko, Northern Sweden: generalizations and differences in ecosystem and plant type responses to global change
    Wijk, M.T. van; Clemmensen, K.E. ; Shaver, G.R. ; Williams, M. ; Callaghans, T.V. ; Chapin, F.S. ; Cornelissen, J.H.C. ; Gough, L. ; Hobbie, S.E. ; Jonasson, S. ; Lees, J.A. ; Michelsen, A. ; Press, M.C. ; Richardsons, S.J. ; Rueth, H. - \ 2004
    Global Change Biology 10 (2004)1. - ISSN 1354-1013 - p. 105 - 123.
    simulated environmental-change - arctic polar semidesert - uv-b radiation - climate-change - tussock tundra - growth-responses - betula-nana - reproductive development - terrestrial ecosystems - eriophorum-vaginatum
    Long-term ecosystem-level experiments, in which the environment is manipulated in a controlled manner, are important tools to predict the responses of ecosystem functioning and composition to future global change. We present the results of a meta-analysis performed on the results of long-term ecosystem-level experiments near Toolik Lake, Alaska, and Abisko, Sweden. We quantified aboveground biomass responses of different arctic and subarctic ecosystems to experimental fertilization, warming and shading. We not only analysed the general patterns but also the differences in responsiveness between sites and regions. Aboveground plant biomass showed a broad similarity of responses in both locations, and also showed some important differences. In both locations, aboveground plant biomass, particularly the biomass of deciduous and graminoid plants, responded most strongly to nutrient addition. The biomass of mosses and lichens decreased in both locations as the biomass of vascular plants increased. An important difference between the two regions was the smaller positive aboveground biomass response of deciduous shrubs in Abisko as compared with Toolik Lake. Whereas in Toolik Lake Betula nana increased its dominance and replaced many of the other plant types, in Abisko all vascular plant types increased in abundance without major shifts in relative abundance. The differences between the responses of the dominant vegetation types of the Toolik Lake region, i.e. tussock tundra systems, and that of the Abisko region, i.e. heath systems, may have important implications for ecosystem development under expected patterns of global change. However, there were also large site-specific differences within each region. Several potential mechanistic explanations for the differences between sites and regions are discussed. The response patterns show the need for analyses of joint data sets from many regions and sites, in order to uncover common responses to changes in climate across large arctic regions from regional or local responses.
    Analyzing the ecosystem carbon dynamics of four European coniferous forests using a biogeochemistry model
    Churkina, G. ; Tenhunen, J. ; Thornton, P. ; Falge, E. ; Elbers, J.A. ; Erhard, M. ; Grünwald, T. ; Kowalski, A. ; Rannik, Ü. ; Sprinz, D. - \ 2003
    Ecosystems 6 (2003)2. - ISSN 1432-9840 - p. 168 - 184.
    time climate variability - daily solar-radiation - global change - gap models - terrestrial ecosystems - atmospheric transport - regional applications - deciduous forest - nitrogen budgets - satellite data
    This paper provides the first steps toward a regional-scale analysis of carbon (C) budgets. We explore the ability of the ecosystem model BIOME-BGC to estimate the daily and annual C dynamics of four European coniferous forests and shifts in these dynamics in response to changing environmental conditions. We estimate uncertainties in the model results that arise from incomplete knowledge of site management history (for example, successional stage of forest). These uncertainties are especially relevant in regional-scale simulations, because this type of information is difficult to obtain. Although the model predicted daily C and water fluxes reasonably well at all sites, it seemed to have a better predictive capacity for the photosynthesis-related processes than for respiration. Leaf area index (LAI) was modeled accurately at two sites but overestimated at two others (as a result of poor long-term climate drivers and uncertainties in model parameterization). The overestimation of LAI (and consequently gross photosynthetic production (GPP)), in combination with reasonable estimates of the daily net ecosystem productivity (NEP) of those forests, also illustrates the problem with modeled respiration. The model results suggest that all four European forests have been net sinks of C at the rate of 100-300 gC/m2/y and that this C sequestration capacity would be 30%-70% lower without increasing nitrogen (N) deposition and carbon dioxide (CO2) concentrations. The magnitude of the forest responses was dependent not only on the rate of changes in environmental factors, but also on site-specific conditions such as climate and soil depth. We estimated that the modeled C exchange at the study sites was reduced by 50%-100% when model simulations were performed for climax forests rather than regrowing forests. The estimates of water fluxes were less sensitive to different initializations of state variables or environmental change scenarios than C fluxes.
    Relationships at the aboveground-belowground interface: plants, soil biota and soil processes
    Porazinska, D.L. ; Bardgett, R.D. ; Postma-Blaauw, M.B. ; Hunt, H.W. ; Parsons, A.N. ; Seastedt, T.R. ; Wall, D.M. - \ 2003
    Ecological Monographs 73 (2003)3. - ISSN 0012-9615 - p. 377 - 395.
    experimental grassland ecosystems - tallgrass prairie - terrestrial ecosystems - species-diversity - microbial biomass - nitrogen - biodiversity - decomposition - productivity - communities
    Interactions at the aboveground-below ground interface provide important feedbacks that regulate ecosystem processes. Organisms within soil food webs are involved in processes of decomposition and nutrient mineralization, and their abundance and activity have been linked to plant ecophysiological traits such as species identity and the quality and quantity of plant tissue. We tested aboveground-below ground diversity relationships in a naturally developed plant community of native tallgrass prairie by taking soil samples from beneath naturally established grass tillers of chosen characteristics (e.g., homogeneous vs. heterogeneous plant combinations or C-4 vs. C-3 photosynthetic pathway) without imposing any disturbances to existing plant-soil relationships. The goal of this study was to elucidate the consequences, for soil microbiota (microflora phospholipid fatty acids, protozoa, and nematode functional groups) and for C and N mineralization, of plant community properties such as species richness, resource quality, resource heterogeneity, species identity, and presence of exotics. None of the biotic or abiotic soil variables was related to plant resource heterogeneity. Protozoa were not responsive to any of the plant community traits. Some bacterial and nematode groups were affected by plant characteristics specific to a particular plant species, but no uniform pattern emerged. Invasive and native plants generally were similar with respect to soil variables tested in this study. The lack of clear responses of soil variables to plant community traits indicates that idiosyncratic effects dominate both at the plant and soil biotic level and that generalized plant and soil diversity effects are hard to predict.
    Uncertainty of critical loads based on the Ellenberg indicator value for acidity
    Wamelink, G.W.W. ; Dobben, H.F. van - \ 2003
    Basic and Applied Ecology 4 (2003)6. - ISSN 1439-1791 - p. 515 - 523.
    terrestrial ecosystems - field-measurements - nitrogen - forests - eutrophication - acidification - netherlands - moisture - sulfur
    The relationship between average Ellenberg's indicator values per vegetation releve and environmental values measured in the field shows a large variability. This variability might have a strong impact on critical loads determined by dynamic models (i.e. by modelling the effect of acid deposition on the vegetation composition). To derive critical loads, acidity ranges per vegetation type are determined using Ellenberg indicator values, and subsequently translated into soil pH values. Acidity ranges are here defined as the range in which 80% of the characteristic species of a vegetation type can potentially occur. In this paper we explore the uncertainty in the modelled pH ranges and discuss the possible implications for critical loads. The effect of an overall translation instead of transfer functions per class on the estimated critical soil pH, and therefore on the critical loads, was calculated for a set of vegetation types in The Netherlands. The use of these different transfer functions resulted in critical soil pH values that differed by 0.2 pH units on average. For 12 out of the 17-investigated vegetation types this effect is of the same magnitude as the modelled effect of a 50% reduction in acidifying deposition. We also calculated the intrinsic uncertainty in the critical load estimates (i.e. due to the uncertainty in the regression parameters), which turned out to be even larger than the uncertainty due to the use of different transfer functions. This type of uncertainty was smaller when transfer functions per vegetation class were used (95% confidence interval c 1.4 vs c 1.7 pH units). Although the modelled critical loads have a large amount of uncertainty, they are not much different from experimentally derived critical loads. We conclude that modelled critical loads can be used when no empirical data are present, although they have to be,regarded as less certain. The uncertainty can be reduced by incorporating transfer functions per vegetation class.
    Effects of climate and land-use change on lowland stream ecosystems
    Walsum, P.E.V. van; Verdonschot, P.F.M. ; Runhaar, J. - \ 2002
    Wageningen : Alterra (Alterra-report 523) - 200
    klimaatverandering - landgebruik - ecosystemen - hydrologie - aquatische ecosystemen - terrestrische ecosystemen - ecohydrologie - climatic change - land use - ecosystems - hydrology - aquatic ecosystems - terrestrial ecosystems - ecohydrology
    During the past decades human interference in regional hydrologic systems has intensified. These systems act as an integrating medium. They link climate, human activities and ecological processes through groundwater and surface water interactions. In this study we have examined the potential impacts of climate and land-use change on the streams Beerze and Reusel in the Netherlands. For examining the potential impacts of climate change we have followed a scheme involving predictions for: - indirect effects of climate change, that are transferred to ecological subsystems through the regional hydrologic system - direct effects of climate change, through the direct influence of temperature on the growth and reproduction of plant species, and the dispersal of aquatic invertebrates Large effects on peak discharges are predicted for some of the climate scenarios. Effects on terrestrial ecosystems are moderate and mainly positive. Under all scenarios the climate change had a significantly negative effect on the stream community of the aquatic ecosystem.
    Effecten emissiebeleid voor verzuring op de natuur
    Vries, W. de; Dobben, H.F. van; Herk, C.M. van; Roelofs, J. ; Pul, A. van; Hinsberg, A. van; Duijzer, J. ; Erisman, J.W. - \ 2002
    ArenA 8 (2002)7. - ISSN 1383-7974 - p. Dossier105 - 108.
    verzuring - zure depositie - ammoniak - emissie - luchtverontreiniging - luchtkwaliteit - overheidsbeleid - ecosystemen - natuurbescherming - terrestrische ecosystemen - aquatische ecosystemen - natuur - acidification - acid deposition - ammonia - emission - air pollution - air quality - government policy - ecosystems - nature conservation - terrestrial ecosystems - aquatic ecosystems - nature
    Een evaluatie van de emissiebeperkende maatregelen die van invloed zijn op de terrestrische en in mindere mate op de aquatische ecosystemen. Met name de reducties in zwavelbelasting op korstmossen en in stikstof en zuurbelasting op vennen worden beschreven
    Evaluatie van de verzuringsdoelstellingen: de onderbouwing
    Albers, R. ; Beck, J. ; Bleeker, A. ; Bree, L. van; Dam, J. van; Eerden, L. v.d.; Freijer, J. ; Hinsberg, A. van; Marra, M. ; Salm, C. v.d.; Tonneijck, A. ; Vries, W. de; Wesselink, L. ; Woretelboer, F. - \ 2001
    Bilthoven : RIVM
    milieubeleid - evaluatie - milieueffect - zure depositie - waarden - modellen - nederland - terrestrische ecosystemen - atmosferische depositie - beleidsevaluatie - luchtverontreiniging - milieu - vegetatie - verzuring - environmental policy - evaluation - environmental impact - acid deposition - values - models - netherlands - terrestrial ecosystems
    Effects of climate and land-use change on lowland stream ecosystems : Dutch National Research Programme on Global Air Pollution and Climate Change
    Walsum, P.E.V. van; Verdonschot, P.F.M. ; Runhaar, J. - \ 2001
    Wageningen : Alterra, Research Instituut voor de Groene Ruimte - ISBN 9789058510471 - 201
    ecosystemen - laaglandgebieden - klimaatfactoren - klimaatverandering - nederland - aquatische ecosystemen - terrestrische ecosystemen - ecologie - grondwater - hydrologie - landgebruik - oppervlaktewater - ecosystems - lowland areas - climatic factors - climatic change - netherlands - aquatic ecosystems - terrestrial ecosystems
    Evaluatie van de verzuringsdoelstellingen: kwantificering van de effecten van emissievarianten op half-natuurlijke terrestrische ecosystemen
    Mol-Dijkstra, J.P. ; Kros, J. ; Hinsberg, A. van - \ 2001
    Wageningen : Alterra (Alterra-rapport 342) - 63
    milieubeleid - evaluatie - milieueffect - zure depositie - waarden - modellen - nederland - terrestrische ecosystemen - atmosferische depositie - bodemkwaliteit - milieu - natuurbescherming - simulatiemodel - verzuring - environmental policy - evaluation - environmental impact - acid deposition - values - models - netherlands - terrestrial ecosystems
    In het kader van de evaluatie verzuringsdoelstellingen zijn depositiescenario's geëvalueerd met de dynamische modellen SMART2/MOVE. Het blijkt dat door naijleffecten overschrijdingen van normen kunnen optreden, terwijl kritische depositieniveaus niet meer overschreden worden. De vertraging is ongeveer tien jaar. Voor adequate bescherming van bossen en natuurgebieden is het van belang dat naast Nederlandse ook buitenlandse emissies gereduceerd worden.
    Bridging gaps in fragmented marshland : applying landscape ecology for bird conservation
    Foppen, R.F.B. - \ 2001
    Wageningen University. Promotor(en): P.F.M. Opdam. - S.l. : S.n. - ISBN 9789058084897 - 168
    vogels - terrestrische ecosystemen - fragmentatie - verspreiding - populaties - moerassen - wetlands - nederland - landschapsecologie - moerasvogels - natuur - versnippering - birds - terrestrial ecosystems - fragmentation - dispersal - populations - marshes - wetlands - netherlands

    An important part of the natural values in The Netherlands is based on the fact that the country has a unique geographical position in temperate lowland Europe at the mouth of the rivers Rhine and Meuse. This creates a number of interesting gradient situations e.g. between saltwater and freshwater systems, between eutrophic and oligotrophic systems, and between tidal, streaming and stagnant waters. This position offers excellent conditions for a wide variety of wetland systems: river and clay marshlands with open water and macrophyte vegetation like reedlands, peat marshland with bogs, fens and mires, as well as estuaries with saltmarshes. This marshland diversity resulted in a very diverse avifauna with many species occurring in high densities. The diversity and quantity of these wetland ecosystems, however, is severely threatened and consequently the number and the distribution of typical marshland bird species decreased (Den Boer 2000). Acidification, euthrophication and desiccation, cultivation and unfavourable management practices all contributed to a decline of total area and an increasing degree of fragmentation of the remaining habitat for marshland birds (Figure 1.1). The Dutch Nature Policy Plan, published in 1990 (NPP 1990), mentioned fragmentation as one of the most important threats to biodiversity. A nation-wide ecological network of nature areas was proposed as the solution for this problem. It is vital for the success of this strategy that the implementation is underpinned by ecological knowledge of the underlying processes in this network system.

    The process of habitat fragmentation leads to landscapes with dispersed small populations within an inhospitable matrix. Small populations are likely to go extinct by stochastic demographic fluctuations. Consequently, the viability of these small populations depends on the likelihood that they will be recolonised by individuals from elsewhere. Crucial is whether the distances most individuals are likely to cover between years, as a result of the dispersal process, are large enough compared to the interpatch distances within a landscape. A set of subpopulations (or metapopulation), may be viable, even when all subpopulations are small in size under the condition that local extinction and recolonisation rates are balanced.

    Fragmentation can lead to a conservation problem, which asks for spatial solutions. In a multifunctional society, like The Netherlands, finding and implementing effective solutions are part of a spatial planning process. The way from problem definition to the actual implementation of a plan can be regarded as a cyclic planning process (Figure 1.2) with successive phases on problem detection, exploring solutions, development of landscape scenarios, designing an actual plan and plan evaluation. Often, ecological knowledge is poorly used in such planning processes. It is probably due to the fact that the knowledge is not tailored for the different phases of the planning cycle. This asks for generalisations, from case studies to a variety of landscapes. It also asks for aggregation of knowledge on single species to knowledge on multispecies level.

    It is a challenge for landscape ecology to develop and support such an approach and link ecology and spatial planning and, to my opinion, knowledge systems should play a major role (Figure 1.3).

    This thesis is an attempt to elaborate this landscape ecological line of thought for the problem of fragmented marshland and conservation of bird species. It tries to bridge two 'gaps'. Firstly, the gap (in literal sense) between remaining pieces of marshland. What is an effective spatial strategy for the persistence of marshland birds in The Netherlands? How should we 'bridge' the gaps between our remaining habitats? The second gap is metaphorical and refers to the transfer of ecological knowledge gathered in case studies and at the species level into tools and instruments for application in nature management and policy. In conclusion, the central questions of this thesis are: (1) under what spatial conditions do marshland birds demonstrate negative effects of fragmentation and (2) how to utilise ecological knowledge for practical tools in conservation?

    In Chapter 2 distribution data of six typical marshland passerines occurring in heavily fragmented landscapes in Gelderland and Sealand Flanders are analysed. Some of the species are common, like the reed warbler and the reed bunting (occurring in >50% of the habitat patches), others are scarce or rare (sedge warbler, great reed warbler, penduline tit and bluethroat). After correcting for patch size and quality, in most cases occurrence is significantly explained by patch connectivity, a measure for the spatial configuration of the patch. The response of species to fragmentation is variable, but the analyses confirm that in many landscapes in The Netherlands habitat fragmentation negatively influences occurrence of bird populations. By linking the fraction of occupied patches to ecologically scaled landscape indices (ESLI) a diagnostic tool was set up. The ESLI 'average patch carrying capacity' is a good estimator of the fraction of occupied patches and that the 50% occupation threshold (assumed to be a viability threshold according to Vos et al. 2001) will be reached at an average patch carrying capacity of 2-5 territories. This diagnostic instrument is practical and quickly applicable because no field data are required, the essential information concerning carrying capacity can be collected from literature.

    Spatially explicit population models, mathematical models simulating population dynamics of a species with subdivided populations, are useful research tools to explore and understand the behaviour of populations in a fragmented landscape. These models require lots of information for parameterisation of the essential parameters, the most important source are field data. Particularly quantitative data on the dispersal and emigration rates are essential, though collecting these data is time-consuming and difficult. In Chapter 3 the results of a field study on the great reed warbler are presented. The study area consisted of reed beds along lakes, total length around 15 kilometres. During 1994-2000 over 1100 individuals were colour banded and more than 250 individuals were resighted in one or more following years. By analysing records of marked individuals, survival, dispersal and emigration rates were quantified. Most individuals show displacements within the study area. Survival is estimated by analysing the capture-recapture data using the program MARK and depends on age, sex and year. Emigration rates are estimated by dividing the study area in six equal parts and analysing the differences in local survival between the parts and various combinations. The resulting function describes the relation between the emigration rate and the size of an area. The demographic data and the quantification of dispersal are subsequently used for the parameterisation of a metapopulation model. This model is decribed and used in the following chapters.

    Chapter 4 demonstrates the influence of large environmental impacts on the dynamics of a metapopulation. In the last decades a number of passerines wintering in the Sahel zone suffers from the droughts. The sedge warbler is one of those species. After drought years (like in the mid-seventies and eighties) the population shows a decline of more than 50%. After these collapses the population recovers, but not in all marshlands. An analysis of the population trends in a large number of marshlands in The Netherlands indicated that populations in large marshlands recovered quickly, but that small and relatively isolated populations, like in the eastern and southern parts of the country, did not recover at all. Exercises with a metapopulation model support the hypothesis that this lack of resilience is due to fragmentation effects. Populations of fragmented areas are particularly vulnerable for catastrophic events, probably because certain thresholds for population viability are linked with population size.

    Chapter 5 elaborates on the role of low quality habitats (sinks) in a metapopulation. Persistence of sink populations depends on nearby source populations. However, do sink areas also contribute to the persistence of source areas? In a riverine landscape in the province of Gelderland a number of large marshlands are located close to each other, these constitute source areas for the reed warbler. In a radius of 20-30 kilometres around these marshlands hundreds of small marshlands occur in a landscape dominated by agriculture. A field study demonstrated that in many of these small reed elements reed warblers occur. A regression analysis shows that the habitat quality of these habitat patches is poor and that they most likely are to be considered sink areas. Furthermore, spatial parameters are very important in explaining the probability of occurrence, the abundance and also extinction and recolonisation rates of the habitat patches. In isolated patches the probability of occurrence is low, densities are low, the probability of extinction is high and recolonisation probabilities are low. Thus reed warbler populations in these small elements show metapopulation dynamics. Using a spatially explicit population model proves that sink areas do contribute to the stability and persistence of source areas. A recovery after a population decline is much faster in source areas embedded in a network with sink patches than in source areas with no sinks around. This influence however, depends on the spatial conditions. For reed warblers mainly the sink areas within 2-5 kilometres of a source patch are of importance, and the total number of individuals supported by the sinks should be at least 25% of the source population size.

    In Chapter 6 I analyse distribution data of the bittern in The Netherlands. The bittern is a scarce breeding bird, occurring in less than 50% of all suitable reed dominated marshlands. The species is rare in the eastern, north-eastern and southern parts of the country, although suitable habitat patches occur. A regression model is used to predict probability of occurrence of the bittern in a patch given the size, abiotic (soil) conditions of the marshland and the connectivity. The results indicate that low probability of occurrence of the bittern in certain regions can be explained by unfavourable spatial conditions. The predictions per habitat patch are subsequently used as a calibration set for a simple expert model, SCAN, based on connectivity. The model uses a connectivity value for grid cells of 250x250 meters as an indicator of spatial conditions. The SCAN output gives satisfactory results and correlates well with the regression model predictions. It is considered a useful instrument for problem detection, although the challenge is to find generic rules to translate the model output into probability of occurrence or persistence measures.

    In Chapters 2-6 a number of methods is introduced for the analysis of species occurrence and persistence in fragmented landscapes: developing landscape indices (Chapter 2), metapopulation models (Chapter 4 and 5) and regression models (Chapter 2 and 6). Can we develop an instrument that integrates the various methods and is applicable on landscape rather than on species level? In Chapter 7 a rule-based system is described that combines the merits of all previously mentioned methods. Central issue is the key-patch approach. A key patch is defined as a habitat patch within a habitat network of such a size that the probability of extinction of the local population is less than 5% in 100 years. It is the basis of a persistent metapopulation. The predictive models resulting from the various regression analyses are used to indicate key population standards for a number of species. With help of metapopulation models for two ecoprofiles, a marshland passerine 'reed warbler' and a marshland heron 'bittern' these key population standards are extrapolated to landscape configurations. Literature data on various species groups are used to test the validity of the standards. Three standards are proposed, for long-lived large vertebrates (example: bittern, otter): 20 individuals, for middle-long lived, medium sized vertebrates (example: great reed warbler): 40 individuals and for short-lived, small vertebrates (reed warbler, voles): 100 individuals. These standards are implemented in a GIS and rule-based system, called LARCH, and this is considered a useful evaluation tool for spatial scenarios and plans.

    In Chapter 8 I conclude that the occurrence and persistence of marshland bird species in The Netherlands is negatively influenced by the current degree of habitat fragmentation. I also discuss the value of the presented instruments and tools for application in the different phases of the planning cycle.

    What spatial strategy is effective to bridge the gaps between isolated marshlands? The results of this thesis indicate that the primary option is to enlarge existing marshlands, creating at least five key populations for most of the marshland birds. This requires extension of the size of most existing marshlands by nature restoration, aiming at totals of 5000-10 000 ha. Next, a marshland 'backbone' should be created with restoration of medium-sized marshlands along several axes. By this way marshland bird populations in the periphery are better 'connected' with the core areas and will show a higher, regional, persistence. It will also enhance the probability of occurrence and saturation in existing marshland areas and thus is a cost-effective measure.

    Gebiedsspecifieke, kritische depositieniveaus voor stikstof en zuur voor terrestrische ecosystemen
    Vries, W. de; Salm, C. van der; Hinsberg, A. van; Kros, J. - \ 2000
    Milieu 15 (2000)3. - ISSN 0920-2234 - p. 144 - 158.
    milieubescherming - verzuring - normen - zure depositie - stikstof - depositie - zwavel - nederland - terrestrische ecosystemen - environmental protection - acidification - standards - acid deposition - nitrogen - deposition - sulfur - netherlands - terrestrial ecosystems
    Op basis van de resultaten kunnen nieuwe verzuringsdoelstellingen worden afgeleid in relatie tot een gewenst beschermingsareaal voor een gegeven effect
    Corridors of the Pan-European ecological network: concepts and examples for terrestrial and freshwater vertebrates
    Foppen, R.P.B. ; Bouwma, I.M. ; Kalkhoven, J.T.R. ; Dirksen, J. ; Opstal, S. van - \ 2000
    Tilburg : European Centre for Nature Conservation - ISBN 9789076762050 - 56
    ecologie - verspreiding - gewervelde dieren - fragmentatie - europa - waterorganismen - migratie - terrestrische ecosystemen - netwerken - ecology - dispersal - vertebrates - fragmentation - europe - aquatic organisms - migration - terrestrial ecosystems - networks
    Graadmeter natuurwaarde terrestrisch : verslaglegging van de uitgevoerde werkzaamheden
    Koolstra, B.J.H. ; Alkemade, R. ; Bugter, R.J.F. ; Chardon, J.P. ; Grashof, C.J. ; Kuijk, J.D. van; Kwak, R.M.G. ; Mabelis, A.A. ; Slim, P.A. ; Brink, B. ten; Dobben, H.F. van; Foppen, R.P.B. ; Reijnen, M.J.S.M. ; Schotman, A.G.M. ; Sprangers, J.T.C.M. ; Wamelink, G.W.W. - \ 1999
    [Wageningen] : Instituut voor Bos- en Natuuronderzoek (IBN-DLO) (Werkdocument / DLO Natuurplanbureau-onderzoek 1999/11) - 51
    natuurbescherming - kwaliteit - meting - monitoring - nederland - natuur - terrestrische ecosystemen - nature conservation - quality - measurement - monitoring - netherlands - nature - terrestrial ecosystems
    Bioavailability of heavy metals in terrestrial and aquatic systems: A quantitative approach
    Plette, A.C.C. ; Nederlof, M.N. ; Temminghoff, E.J.M. ; Riemsdijk, W.H. van - \ 1999
    Environmental Toxicology and Chemistry 18 (1999)9. - ISSN 0730-7268 - p. 1882 - 1890.
    zware metalen - biologische beschikbaarheid - biota - soortvorming - bodemchemie - aquatische ecosystemen - terrestrische ecosystemen - ecotoxicologie - heavy metals - bioavailability - biota - speciation - soil chemistry - aquatic ecosystems - terrestrial ecosystems - ecotoxicology
    Assessment of long-term effects of climate change on biodiversity and vulnerability of terrestrial ecosystems
    Oene, H. van; Berendse, F. ; Alkemade, J.R.M. ; Bakkenes, M. ; Ihle, F. ; Kovel, C.G.F. de - \ 1999
    Wageningen [etc.] : Wageningen University, Nature Conservation and Plant Ecology Group [etc.] - ISBN 9789058510150 - 168
    meteorologie - klimaatverandering - nadelige gevolgen - soortendiversiteit - ecosystemen - biodiversiteit - nederland - terrestrische ecosystemen - meteorology - climatic change - adverse effects - species diversity - ecosystems - biodiversity - netherlands - terrestrial ecosystems
    Impact of climate change on terrestrial ecosystems, rivers and coastal wetlands
    Geijn, S.C. van de; Mohren, G.M.J. ; Kwadijk, J. ; Higler, L.W.G. - \ 1998
    Milieu 13 (1998)5. - ISSN 0920-2234 - p. 242 - 254.
    klimaatverandering - rivieren - wetlands - kustgebieden - regionaal beleid - gewasproductie - nederland - zeeniveau - terrestrische ecosystemen - aquatische ecosystemen - waddenzee - climatic change - rivers - coastal areas - regional policy - crop production - netherlands - sea level - terrestrial ecosystems - aquatic ecosystems - wadden sea
    Nematode communities of northern temperate grassland ecosystems.
    Goede, R.G.M. de; Bongers, T. - \ 1998
    Giessen : Focus - ISBN 9783883494715 - 338
    nematoda - ecosystemen - graslanden, gematigde streken - geografische verdeling - europa - terrestrische ecosystemen - diergemeenschappen - nematoda - ecosystems - temperate grasslands - geographical distribution - europe - terrestrial ecosystems - animal communities
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