Staff Publications

Staff Publications

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

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

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

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

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    We will mail you new results for this query: keywords==extinction risk
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Dilution versus facilitation: Impact of connectivity on disease risk in metapopulations
Huang, Z.Y.X. ; Langevelde, F. van; Prins, H.H.T. ; Boer, W.F. de - \ 2015
Journal of Theoretical Biology 376 (2015). - ISSN 0022-5193 - p. 66 - 73.
infectious-disease - pathogen transmission - batrachochytrium-dendrobatidis - forest fragmentation - extinction risk - host diversity - living fast - biodiversity - dynamics - ecology
Epidemiological studies have suggested that increasing connectivity in metapopulations usually facilitates pathogen transmission. However, these studies focusing on single-host systems usually neglect that increasing connectivity can increase species diversity which might reduce pathogen transmission via the ‘dilution effect’, a hypothesis whose generality is still disputed. On the other hand, studies investigating the generality of the dilution effect were usually conducted without considering habitat structure, which is surprising as species loss is often driven by habitat fragmentation. Using a simple general model to link fragmentation to the dilution effect, we determined the effect of connectivity on disease risk and explored when the dilution effect can be detected. We showed that landscape structure can largely modify the diversity-disease relationship. The net impact of connectivity on disease risk can be either positive or negative, depending on the relative importance of the facilitation effect (through increasing contact rates among patches) versus the dilution effect (via increasing species richness). We also demonstrated that different risk indices (i.e. infection prevalence and abundance of infected hosts) react differently to increasing connectivity and species richness. Our study may contribute to the current debate on the dilution effect, and a better understanding of the impacts of fragmentation on disease risks.
Is green infrastructure an effective climate adaption strategy for conserving biodiversity? A case study with the great crested newt
Teeffelen, A.J.A. van; Vos, C.C. ; Jochem, R. ; Baveco, J.M. ; Meeuwsen, H. ; Hilbers, J.P. - \ 2015
Landscape Ecology 30 (2015)5. - ISSN 0921-2973 - p. 937 - 954.
population viability analysis - triturus-cristatus - amphibian populations - extinction risk - habitat - conservation - landscapes - management - dynamics - patterns
Context Increasing the amount of green infrastructure, defined as small-scale natural landscape elements, has been named as a climate adaptation measure for biodiversity. While green infrastructure strengthened ecological networks in some studies, it is not known whether this effect also holds under climate change, and how it compares to other landscape adaptation options. Objectives We assessed landscape adaptation options under scenarios of climate change for a dispersal-limited and climate-sensitive species: great crested newt, Triturus cristatus. Methods A spatially-explicit modelling framework was used to simulate newt metapopulation dynamics in a case study area in the Netherlands, under alternative spatial configurations of 500 ha to-be-restored habitat. The framework incorporated weather-related effects on newt recruitment, following current and changing climate conditions. Results Mild climate change resulted in slightly higher metapopulation viability, while more severe climate change (i.e. more frequent mild winters and summer droughts) had detrimental effects on metapopulation viability. The modelling framework revealed interactions between climate and landscape configuration on newt viability. Restoration of ponds and terrestrial habitat may reduce the negative effects of climate change, but only when certain spatial requirements (habitat density, connectivity) as well as abiotic requirements (high ground water level) are met. Conclusions Landscape scenarios where habitat was added in the form of green infrastructure were not able to meet these multiple conditions, as was the case for a scenario that enlarged core areas. The approach allowed a deduction of landscape design rules that incorporated both spatial and abiotic requirements resulting in more effective climate adaptation options.
Changes of bat activity, species richness, diversity and community composition over an altitudinal gradient in the Soutpansberg range, South Africa
Linden, V.M.G. ; Weier, S.M. ; Gaigher, I. ; Kuipers, H.J. ; Weterings, M.J.A. ; Taylor, P. - \ 2014
Acta Chiropterologica 16 (2014)1. - ISSN 1508-1109 - p. 27 - 40.
small mammal diversity - higher-taxon richness - elevational gradient - habitat preferences - model selection - extinction risk - climate-change - biodiversity - chiroptera - patterns
Bats are important indicator species which can help in identifying areas where conservation efforts should be concentrated and whether these areas are affected by ongoing climate change. To elucidate factors limiting and influencing the elevational distribution of bats in a recognised biodiversity hotpot, the Soutpansberg mountain range (in Vhembe Biosphere Reserve) of northern South Africa, we collected data in and around the Luvhondo Private Nature Reserve, by catching and acoustically monitoring bats over an altitudinal gradient from 900 to 1,748 m. A total of 18 different species could be recorded. Two species, namely Pipistrellus hesperidus and Chaerephon cf. ansorgei appeared to be present and dominant at all altitudes. Activity, species richness and diversity significantly decreased with increasing altitude, whereas community composition was not related to altitude and no endemics to either low or high altitude were detected. It is likely that the change of species richness and diversity over altitude is caused by other factors correlated with altitude such as vegetation type, area size, energy availability and climatic differences. Our research demonstrated that lower altitudes are richer and more diverse in bat species and since no highland endemics have been discovered, conservation efforts in the area, regarding bats, should not ignore these lower altitudes which are most susceptible to human impacts leading to habitat degradation due to over-grazing, bush encroachment, cultivation and denudation of large trees for firewood collection.
Museum specimens reveal loss of pollen host plants as key factor driving wild bee decline in The Netherlands
Scheper, J.A. ; Reemer, M. ; Kats, R.J.M. van; Ozinga, W.A. ; Linden, G.T.J. van der; Schaminee, J.H.J. ; Siepel, H. ; Kleijn, D. - \ 2014
Proceedings of the National Academy of Sciences of the United States of America 111 (2014)49. - ISSN 0027-8424 - p. 17552 - 17557.
pollinator interactions - multimodel inference - behavioral ecology - model selection - extinction risk - solitary bees - range size - land-use - conservation - hymenoptera
Evidence for declining populations of both wild and managed bees has raised concern about a potential global pollination crisis. Strategies to mitigate bee loss generally aim to enhance floral resources. However, we do not really know whether loss of preferred floral resources is the key driver of bee decline because accurate assessment of host plant preferences is difficult, particularly for species that have become rare. Here we examine whether population trends of wild bees in The Netherlands can be explained by trends in host plants, and how this relates to other factors such as climate change. We determined host plant preference of bee species using pollen loads on specimens in entomological collections that were collected before the onset of their decline, and used atlas data to quantify population trends of bee species and their host plants. We show that decline of preferred host plant species was one of two main factors associated with bee decline. Bee body size, the other main factor, was negatively related to population trend, which, because larger bee species have larger pollen requirements than smaller species, may also point toward food limitation as a key factor driving wild bee loss. Diet breadth and other potential factors such as length of flight period or climate change sensitivity were not important in explaining twentieth century bee population trends. These results highlight the species-specific nature of wild bee decline and indicate that mitigation strategies will only be effective if they target the specific host plants of declining species.
Use it or lose it: measuring trends in wild species subject to substantial use
Tierney, M. ; Almond, R. ; Stanwell-Smith, D. ; McRae, L. ; Zöckler, C. ; Collen, B. ; Walpole, M. ; Hutton, J. ; Bie, S. de - \ 2014
Oryx 48 (2014)03. - ISSN 0030-6053 - p. 420 - 429.
living planet index - extinction risk - biodiversity - populations - management - conservation - sustainability - birds - sea
The unsustainable use of wild animals and plants is thought to be a significant driver of biodiversity loss in many regions of the world. The international community has therefore called for action to ensure the sustainable use of living resources and safeguard them for future generations. Indicators that can track changes in populations of species used by humans are essential tools for measuring progress towards these ideals and informing management decisions. Here we present two indicators that could be used to track changes in populations of utilized vertebrate species and levels of harvest sustainability. Preliminary results based on sample data both at the global level and for the Arctic show that utilized species are faring better than other species overall. This could be a consequence of better management of these populations, as indicated by more sustainable harvest levels in recent decades. Limitations of the indicators are still apparent; in particular, there is a lack of data on harvested populations of some vertebrate classes and from certain regions. Focusing monitoring efforts on broadening the scope of data collected and identifying interactions with other potential drivers of decline will strengthen these indicators as policy tools and improve their potential to be incorporated into future sets of indicators to track progress towards global biodiversity targets.
Within-patch habitat quality determines the resilience of specialist species in fragmented landscapes
Ye, X. ; Skidmore, A.K. ; Wang, T. - \ 2013
Landscape Ecology 28 (2013)1. - ISSN 0921-2973 - p. 135 - 147.
metapopulation dynamics - population-dynamics - environmental variation - relative importance - isolation paradigm - extinction risk - effect size - long-term - heterogeneity - persistence
Patch geometry and habitat quality among patches are widely recognized as important factors affecting population dynamics in fragmented landscapes. Little is known, however, about the influence of within-patch habitat quality on population dynamics. In this paper, we investigate the relative importance of patch geometry and within-patch habitat quality in determining population dynamics using a spatially explicit, agent-based model. We simulate two mobile species that differ in their species traits: one resembles a habitat specialist and the other a habitat generalist. Habitat quality varies continuously within habitat patches in space (and time). The results show that spatial variation in within-patch quality, together with patch area, controls population abundance of the habitat specialist. In contrast, the population size of the generalist species depends on patch area and isolation. Temporal variation in within-patch quality is, however, less influential in driving the population resilience of both species. We conclude that specialist species are more sensitive than generalist species to within-patch variation in habitat quality. The patch area-isolation paradigm, developed in metapopulation theory, should incorporate variation in within-patch habitat quality, particularly for habitat specialists.
Metapopulation shift and survival of woodland birds under climate change: will species be able to track?
Schippers, P. ; Verboom-Vasiljev, J. ; Vos, C.C. ; Jochem, R. - \ 2011
Ecography 34 (2011)6. - ISSN 0906-7590 - p. 909 - 919.
woodpecker dendrocopos-medius - habitat fragmentation - range expansion - landscape structure - extinction risk - change impacts - distributions - population - dispersal - scale
Climate change has been widely recognized as a key factor driving changes in species distributions. In this study we use a metapopulation model, with a window of suitable climate moving polewards, to explore population shifts and survival of woodland birds under different climate change scenarios and landscape configurations. Extinction vulnerability and expansion ability are predicted for the middle spotted woodpecker Dendrocopus medius and two alternative r-K strategies under west European climate change scenarios of 1, 2 and 4°C temperature increase per century, corresponding to isotemperature velocities of ca 2, 4 and 8 km yr-1. The simulated northward expansion of the bird's distribution is typically in the range of only 0–3 km yr-1, in spite of 10–20 times larger maximum dispersal distances. This is too slow to track the climate change-driven range contraction of 4 or 8 km yr-1 in the south resulting in metapopulation extinction. Especially K-selected (large-bodied) species are vulnerable in the simulations. With a temperature increase of 4°C per century bird species go extinct within 104–178 yr. We present a simple approximation formula to predict the mean time to metapopulation extinction using 1) the rate of climate change, which determines the speed of range contraction in the south, 2) the size of the distribution range, which serves as a buffer against extinction, and 3) the northward expansion velocity, determined by species traits and landscape properties. Finally, our results indicate that the northward expansion rate is not constant. It will be initially lagged suggesting that recently observed expansion rates might be underestimations of future northward expansion rates
Biodiversity conservation in dynamic landscapes: trade-offs between number, connectivity and turnover of habitat patches
Johst, K. ; Drechsler, M. ; Teeffelen, A.J.A. van; Hartig, F. ; Vos, C.C. ; Wissel, S. ; Wätzold, F. ; Opdam, P.F.M. - \ 2011
Journal of Applied Ecology 48 (2011)5. - ISSN 0021-8901 - p. 1227 - 1235.
metapopulation persistence - tradable permits - extinction risk - disturbances - populations - management - networks - reserves - plant - size
1. Many species are adapted to landscapes with characteristic dynamics generated by ongoing habitat destruction and creation. Climate change and human land use, however, may change the dynamics of these landscapes. Studies have repeatedly shown that many species are not able to cope with such changes in landscape dynamics. Conservation policies must, therefore, explicitly address this threat. The way in which management should be modified when formerly static landscapes become dynamic or when landscape dynamics change is unclear. 2. Using an analytical formula for the rapid assessment of metapopulation lifetime in dynamic landscapes, we investigate if and how changes in one landscape attribute may be compensated by changes in another attribute to maintain species viability. We study such trade-offs considering both spatial (number, connectivity of patches) and temporal (patch destruction and creation rates) landscape attributes. 3. We show that increasing patch destruction can be compensated to a certain extent by improvements in other spatial and/or temporal landscape attributes. Focusing on trade-offs between management options reveals two key factors essential for management decisions: First, the trade-offs are generally nonlinear irrespective of considering spatial or temporal landscape attributes. Secondly, species can be grouped according to their response to particular management options. 4. Synthesis and applications. We demonstrate the usefulness of an analytical formula for calculating trade-offs between landscape attributes for a variety of landscapes and species. Two practical and robust management recommendations can be derived: (i) The nonlinearity of trade-offs implies that the effectiveness of conservation measures depends explicitly on the current level of landscape attributes. It must, therefore, be taken into account in conservation decision making. In particular, the existing level of patch turnover is decisive: if it is already high, improvements in other landscape attributes are ineffective in maintaining species viability. Thus, monitoring the current level of landscape attributes is indispensable for effective biodiversity conservation. (ii) Compensation of increased patch destruction by increased patch creation is only suitable for species with high dispersal propensity adapted to variable environments (aside from habitat patch turnover). This implies that conservation policies which rely on such compensation, like offsetting and conservation banking, are feasible only for this type of species.
Resonance of plankton communities with temperature fluctuations
Beninca, E. ; Dakos, V. ; Nes, E.H. van; Huisman, J. ; Scheffer, M. - \ 2011
American Naturalist 178 (2011)4. - ISSN 0003-0147 - p. E85 - E95.
colored environmental noise - predator-prey system - food-web - population-dynamics - sustained oscillations - extinction risk - chaos - time - phytoplankton - variability
The interplay between intrinsic population dynamics and environmental variation is still poorly understood. It is known, however, that even mild environmental noise may induce large fluctuations in population abundances. This is due to a resonance effect that occurs in communities on the edge of stability. Here, we use a simple predator-prey model to explore the sensitivity of plankton communities to stochastic environmental fluctuations. Our results show that the magnitude of resonance depends on the timescale of intrinsic population dynamics relative to the characteristic timescale of the environmental fluctuations. Predator-prey communities with an intrinsic tendency to oscillate at a period T are particularly responsive to red noise characterized by a timescale of [Formula: see text]. We compare these theoretical predictions with the timescales of temperature fluctuations measured in lakes and oceans. This reveals that plankton communities will be highly sensitive to natural temperature fluctuations. More specifically, we demonstrate that the relatively fast temperature fluctuations in shallow lakes fall largely within the range to which rotifers and cladocerans are most sensitive, while marine copepods and krill will tend to resonate more strongly with the slower temperature variability of the open ocean
Life-history and ecological correlates of population change in Dutch breeding birds.
Turnhout, C.A.M. van; Foppen, R.P.B. ; Leuven, R.S.E.W. ; Strien, A.J. van; Siepel, H. - \ 2010
Biological Conservation 143 (2010)1. - ISSN 0006-3207 - p. 173 - 181.
global climate-change - extinction risk - migratory birds - netherlands - trends - conservation - biodiversity - farmland - declines - britain
Predicting relative extinction risks of animals has become a major challenge in conservation biology. Identifying life-history and ecological traits related to the decline of species helps understand what causes population decreases and sets priorities for conservation action. Here, we use Dutch breeding bird data to correlate species characteristics with national population changes. We modelled population changes between 1990 and 2005 of all 170 breeding bird species using 25 life-history, ecological and behavioural traits as explanatory variables. We used multiple regression and multi-model inference to account for intercorrelated variables, to assess the relative importance of traits that best explain interspecific differences in population trend, and to identify the environmental changes most likely responsible. We found that more breeding birds have increased than decreased in number. The most parsimonious models suggest that ground-nesting and late arrival at the breeding grounds in migratory birds are most strongly correlated with decline. Increasing populations are mainly found among herbivores, sedentary and short-distance migrants, herb- and shrub-nesting birds and large species with a small European range. Declines in ground-nesting and late arriving migrant birds suggest that agricultural intensification, eutrophication and climate change are most likely responsible for changes in Dutch breeding bird diversity. We illustrate that management strategies should primarily focus on the traits and causes responsible for the population changes, in order to be effective and sustainable.
Demographic vulnerability of the clonal and endangered meadow thistle
Jongejans, E. ; Vere, N. de; Kroon, H. de - \ 2008
Plant Ecology 198 (2008)2. - ISSN 1385-0237 - p. 225 - 240.
population viability analysis - extinction risk - sexual reproduction - biological flora - perennial herb - british-isles - plants - dynamics - grassland - fragmentation
For effective management of endangered species it is pivotal to understand why a species is endangered and which key life cycle components are involved in its response to environmental changes. Our objective was to investigate the response of rosettes of the redlisted clonal herb Cirsium dissectum to anthropogenic nutrient enrichment, which threatens its populations, and the consequences of these responses for its population dynamics. We constructed matrix population models with demographic data from three populations and four annual transitions and we decomposed the spatiotemporal variation in projected population growth rates into contributions from life cycle components. These patterns were compared with below-ground rosette dynamics in different fields, and with the below- and above-ground rosette dynamics in a garden experiment with nutrient enrichment and competing grasses. The decomposition analysis revealed that increased clonal rosette formation and decreased rosette survival were driving the spatial variation in the population growth rate. Excavating the below-ground rhizome network revealed a higher rosette turn-over in experimentally fertilized garden plots, which not only resulted in increased plot-level extinction, but also in increased spread of the clonal offspring. This supported the observed trend among field populations: rosette formation trades off with rosette survival. Surviving seedlings were only found in areas where the topsoil had been removed. The endangered C. dissectum is vulnerable when its habitat becomes more productive, because this species does not have the necessary capability to build up biomass. Small-scale disturbances such as created by sod-cutting or trampling cattle are essential for seedling establishment and necessary to render the explorative strategy of rhizomatous clonal spread successful.
Prediction uncertainty of environmental change effects on temperate European biodiversity
Dormann, C. ; Schweiger, O. ; Arens, P.F.P. ; Augenstein, I. ; Aviron, S. ; Bailey, D. ; Baudry, J. ; Billeter, R. ; Bugter, R.J.F. ; Bukacek, R. ; Burel, F. ; Cerny, M. ; Cock, R. de; Blust, G. de; DeFilippi, R. ; Diekotter, T. ; Dirksen, J. ; Durka, W. ; Edwards, P.J. ; Frenzel, M. ; Hamersky, R. ; Hendrickx, F. ; Herzog, F. ; Klotz, S. ; Koolstra, B.J.H. ; Lausch, A. ; Coeur, D. Le; Liira, J. ; Maelfait, J.P. ; Opdam, P. ; Roubalova, M. ; Schermann, A. ; Schermann, N. ; Schmidt, T. ; Smulders, M.J.M. ; Speelmans, M. ; Simova, P. ; Verboom, J. ; Wingerden, W.K.R.E. van; Zobel, M. - \ 2008
Ecology Letters 11 (2008)3. - ISSN 1461-023X - p. 235 - 244.
land-use intensity - climate-change - species richness - agricultural landscapes - extinction risk - cover data - models - distributions - communities - envelope
Observed patterns of species richness at landscape scale (gamma diversity) cannot always be attributed to a specific set of explanatory variables, but rather different alternative explanatory statistical models of similar quality may exist. Therefore predictions of the effects of environmental change (such as in climate or land cover) on biodiversity may differ considerably, depending on the chosen set of explanatory variables. Here we use multimodel prediction to evaluate effects of climate, land-use intensity and landscape structure on species richness in each of seven groups of organisms (plants, birds, spiders, wild bees, ground beetles, true bugs and hoverflies) in temperate Europe. We contrast this approach with traditional best-model predictions, which we show, using cross-validation, to have inferior prediction accuracy. Multimodel inference changed the importance of some environmental variables in comparison with the best model, and accordingly gave deviating predictions for environmental change effects. Overall, prediction uncertainty for the multimodel approach was only slightly higher than that of the best model, and absolute changes in predicted species richness were also comparable. Richness predictions varied generally more for the impact of climate change than for land-use change at the coarse scale of our study. Overall, our study indicates that the uncertainty introduced to environmental change predictions through uncertainty in model selection both qualitatively and quantitatively affects species richness projections.
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