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
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