F. Berendse

Wageningen University, Wageningen, Gelderland, Netherlands

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Publications (260)804.66 Total impact

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    ABSTRACT: Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2) in these ecosystems are closely associated with the permanently wet surface conditions and is susceptible to drought. Especially the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown.This study explores how the timing and characteristics of rain events during photosynthetic active periods, i.e. daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11–year time series of half-hourly eddy-covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden.Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2. The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23 – 0.54 gC m-2. On an annual basis this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season.We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely ignored.This article is protected by copyright. All rights reserved.
    Global Change Biology 01/2015; · 8.22 Impact Factor
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    ABSTRACT: Arctic tundra ecosystems are warming almost twice as fast as the global average1. Permafrost thaw and the resulting release of greenhouse gases from decomposing soil organic carbon have the potential to accelerate climate warming2, 3. In recent decades, Arctic tundra ecosystems have changed rapidly4, including expansion of woody vegetation5, 6, in response to changing climate conditions. How such vegetation changes contribute to stabilization or destabilization of the permafrost is unknown. Here we present six years of field observations in a shrub removal experiment at a Siberian tundra site. Removing the shrub part of the vegetation initiated thawing of ice-rich permafrost, resulting in collapse of the originally elevated shrub patches into waterlogged depressions within five years. This thaw pond development shifted the plots from a methane sink into a methane source. The results of our field experiment demonstrate the importance of the vegetation cover for protection of the massive carbon reservoirs stored in the permafrost and illustrate the strong vulnerability of these tundra ecosystems to perturbations. If permafrost thawing can more frequently trigger such local permafrost collapse, methane-emitting wet depressions could become more abundant in the lowland tundra landscape, at the cost of permafrost-stabilizing low shrub vegetation.
    Nature Climate Change 11/2014; · 15.30 Impact Factor
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    ABSTRACT: Increasing plant species richness generally enhances plant biomass production, which may enhance accumulation of carbon (C) in soil. However, the net change in soil C also depends on the effect of plant diversity on C loss through decomposition of organic matter. Plant diversity can affect organic matter decomposition via changes in litter species diversity and composition, and via alteration of abiotic and/or biotic attributes of the soil (soil legacy effect). Previous studies examined the two effects on decomposition rates separately, and do therefore not elucidate the relative importance of the two effects, and their potential interaction. Here we separated the effects of litter mixing and litter identity from the soil legacy effect by conducting a factorial laboratory experiment where two fresh single root litters and their mixture were mixed with soils previously cultivated with single plant species or mixtures of two or four species. We found no evidence for litter-mixing effects. In contrast, root litter-induced CO2 production was greater in soils from high diversity plots than in soils from monocultures, regardless of the type of root litter added. Soil microbial PLFA biomass and composition at the onset of the experiment was unaffected by plant species richness, whereas soil potential nitrogen (N) mineralization rate increased with plant species richness. Our results indicate that the soil legacy effect may be explained by changes in soil N availability. There was no effect of plant species richness on decomposition of a recalcitrant substrate (compost). This suggests that the soil legacy effect predominantly acted on the decomposition of labile organic matter. We thus demonstrated that plant species richness enhances root litter-induced soil respiration via a soil legacy effect but not via a litter-mixing effect. This implies that the positive impacts of species richness on soil C sequestration may be weakened by accelerated organic matter decomposition.
    Soil Biology and Biochemistry 10/2014; · 4.41 Impact Factor
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    ABSTRACT: Ob selbstregulierte große Herbivoren eine Schlüsselrolle für die Entwicklung von Waldweidelandschaften spielen, bleibt eine entscheidende unbeantwortete Frage, sowohl für die ökologische Theorie als auch den Naturschutz. Wir beschreiben und analysieren, wie eine teilweise selbstregulierte Population von Rindern, Pferden und Rotwild die Entwicklung der Gehölzvegetation im Naturreservat Oostvaardersplassen (Niederlande) beeinflusste. Mit Hilfe von Luftaufnahmen von 1980 bis 2011 analysierten wir die Entwicklung von Sträuchern und Bäumen. Bevor die Groß-Herbivoren 1983 nach Oostvaardersplassen eingeführt wurden, hatte die Gehölzvegetation zugenommen und der Vegetationstyp signifikant die Zahl der Neuansiedlungen beeinflusst. Der Deckungsgrad der Gehölzarten nahm von 1983 bis 1996 weiter zu, nicht nur durch Wachstum der Kronen, sondern auch durch neue Ansiedlungen. Nach 1996 nahm der Deckungsgrad der Gehölzvegetation von 30% auf unter 1% im Jahre 2011 ab, und keine Neuansiedlungen wurden auf den Photographien beobachtet. Die Überlebensraten von Sambucus nigra und Salix spp. nahmen mit der Entfernung zum Grasland ab, welches das bevorzugte Weidehabitat der Groß-Herbivoren darstellt. Diese Ergebnisse unterstützen die Hypothese von der Genießbarkeit durch Vergemeinschaftung. Darüber hinaus zeigen unsere Ergebnisse, dass die relative Abnahme des Deckungsgrades von Sambucus nigra und Salix spp. über eine bestimmte Periode negativ mit dem Deckungsgrad von Sambucus nigra am Anfang dieser Periode korreliert war, wodurch ein gewisser Anhaltspunkt für die Hypothesen von der gemeinschaftsbedingten Abwehr und Abwehr durch Aggregation gegeben wird. Unsere Untersuchungen zeigten Aspekte auf, die notwendig für einen Wald-Grasland-Zyklus sind: ein starker Rückgang der Gehölzvegetation bei hohen Dichten der Groß-Herbivoren und eine Regeneration der Sträucher und Bäume bei geringen Dichten. Dornentragende Sträucher, die wichtig für den Zyklus sind, haben sich bisher noch nicht auf den Grasländern angesiedelt. Es scheint, dass ein zeitweiser Rückgang der Herbivorendichten notwendig ist, um ein Gelegenheitsfenster für die Ansiedlung dieser Gehölzarten zu öffnen.
    Basic and Applied Ecology 08/2014; · 2.39 Impact Factor
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    ABSTRACT: To help restore food availability for birds, arable field margins (extensively managed strips of land sown with grasses and forbs) have been established on European farmland. In this study we describe the effect of field margins on the diet of Eurasian Skylark nestlings and adults living on intensively managed Dutch farmland. We tested the hypotheses that field margins offer a higher diversity of invertebrate prey than intensively managed crops, and that the diet of nestlings receiving food from field margins will therefore be more diverse than that of other nestlings. Field margins had a greater variety of invertebrate prey groups to offer than the intensively managed crops. Coleoptera were the most frequently and most abundantly eaten prey group by both adults and nestlings. Together, Coleoptera, Diptera, Lepidoptera, Hymenoptera and Araneae accounted for 91% of the nestling diet. Nestlings ate larger prey items and a larger proportion of larvae than adults. Almost 75% of both adults and nestlings consumed plant material, perhaps indicating a scarcity of invertebrate resources. When provided with food from field margins, the mean number of invertebrate orders in the nestling diet increased significantly from 4.7 to 5.5 and the number of families from 4.2 to 5.8 per sample. Thus, birds that used field margins for foraging could indeed provide their young with more invertebrate prey groups than birds only foraging in crops and grassland.
    Ardea -Wageningen- 07/2014; 102(2):161-171. · 0.83 Impact Factor
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    ABSTRACT: 1. The storage of carbon (C) and nitrogen (N) in soil are important ecosystem functions. Grassland biodiversity experiments have shown a positive effect of plant diversity on soil C and N storage. However, these experiments all included legumes, which constitute an important N input through N2-fixation. Indeed, the results of these experiments suggest that N2-fixation by legumes is a major driver of soil C and N storage.2. We studied whether plant diversity affects soil C and N storage in the absence of legumes. In an 11-years grassland biodiversity experiment without legumes, we measured soil C and N stocks. We further determined above-ground biomass productivity, standing root biomass, soil organic matter decomposition and N mineralization rates to understand the mechanisms underlying the change in soil C and N stocks in relation to plant diversity and their feedbacks to plant productivity.3. We found that soil C and N stocks increased by 18 and 16% in eight-species mixtures compared to the average of monocultures of the same species, respectively. Increased soil C and N stocks were mainly driven by increased C input and N retention, resulting from enhanced plant productivity, which surpassed enhanced C loss from decomposition. Importantly, higher soil C and N stocks were associated with enhanced soil N mineralization rates, which can explain the strengthening of the positive diversity-productivity relationship observed in the last years of the experiment.4. Synthesis: We demonstrated that also in the absence of legumes plant species richness promotes soil carbon (C) and nitrogen (N) stocks via increased plant productivity. In turn, enhanced soil C and N stocks showed a positive feedback to plant productivity via enhanced N mineralization, which could further accelerate soil C and N storage in the long term.This article is protected by copyright. All rights reserved.
    Journal of Ecology 06/2014; · 5.69 Impact Factor
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    ABSTRACT: The decomposition of dead organic matter is a major determinant of carbon and nutrient cycling in ecosystems, and of carbon fluxes between the biosphere and the atmosphere. Decomposition is driven by a vast diversity of organisms that are structured in complex food webs. Identifying the mechanisms underlying the effects of biodiversity on decomposition is critical given the rapid loss of species worldwide and the effects of this loss on human well-being. Yet despite comprehensive syntheses of studies on how biodiversity affects litter decomposition, key questions remain, including when, where and how biodiversity has a role and whether general patterns and mechanisms occur across ecosystems and different functional types of organism. Here, in field experiments across five terrestrial and aquatic locations, ranging from the subarctic to the tropics, we show that reducing the functional diversity of decomposer organisms and plant litter types slowed the cycling of litter carbon and nitrogen. Moreover, we found evidence of nitrogen transfer from the litter of nitrogen-fixing plants to that of rapidly decomposing plants, but not between other plant functional types, highlighting that specific interactions in litter mixtures control carbon and nitrogen cycling during decomposition. The emergence of this general mechanism and the coherence of patterns across contrasting terrestrial and aquatic ecosystems suggest that biodiversity loss has consistent consequences for litter decomposition and the cycling of major elements on broad spatial scales.
    Nature 05/2014; 509(7499):218-21. · 42.35 Impact Factor
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    ABSTRACT: Rapidly increasing levels of light pollution subject nocturnal organisms to major alterations of their habitat, the ecological consequences of which are largely unknown. Moths are well-known to be attracted to light at night, but effects of light on other aspects of moth ecology, such as larval development and life-history, remain unknown. Such effects may have important consequences for fitness and thus for moth population sizes. To study the effects of artificial night lighting on development and life-history of moths, we experimentally subjected Mamestra brassicae (Noctuidae) caterpillars to low intensity green, white, red or no artificial light at night and determined their growth rate, maximum caterpillar mass, age at pupation, pupal mass and pupation duration. We found sex-specific effects of artificial light on caterpillar life-history, with male caterpillars subjected to green and white light reaching a lower maximum mass, pupating earlier and obtaining a lower pupal mass than male caterpillars under red light or in darkness. These effects can have major implications for fitness, but were absent in female caterpillars. Moreover, by the time that the first adult moth from the dark control treatment emerged from its pupa (after 110 days), about 85% of the moths that were under green light and 83% of the moths that were under white light had already emerged. These differences in pupation duration occurred in both sexes and were highly significant, and likely result from diapause inhibition by artificial night lighting. We conclude that low levels of nocturnal illumination can disrupt life-histories in moths and inhibit the initiation of pupal diapause. This may result in reduced fitness and increased mortality. The application of red light, instead of white or green light, might be an appropriate measure to mitigate negative artificial light effects on moth life history.
    Ecology and Evolution 04/2014; · 1.66 Impact Factor
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    ABSTRACT: Northern peatlands represent a large global carbon store that can potentially be destabilized by summer water table drawdown. Precipitation can moderate the negative impacts of water table drawdown by rewetting peatmoss (Sphagnum spp.), the ecosystem's key species. Yet, the frequency of such rewetting required for it to be effective remains unknown. We experimentally assessed the importance of precipitation frequency for Sphagnum water supply and carbon uptake during a stepwise decrease in water tables in a growth chamber. CO2 exchange and the water balance were measured for intact cores of three peatmoss species (Sphagnum majus, Sphagnum balticum and Sphagnum fuscum) representative of three hydrologically distinct peatland microhabitats (hollow, lawn and hummock) and expected to differ in their water table-precipitation relationships. Precipitation contributed significantly to peatmoss water supply when the water table was deep, demonstrating the importance of precipitation during drought. The ability to exploit transient resources was species-specific; S. fuscum carbon uptake increased linearly with precipitation frequency for deep water tables, whereas carbon uptake by S. balticum and S. majus was depressed at intermediate precipitation frequencies. Our results highlight an important role for precipitation in carbon uptake by peatmosses. Yet, the potential to moderate the impact of drought is species-specific and dependent on the temporal distribution of precipitation.
    New Phytologist 04/2014; · 6.55 Impact Factor
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    ABSTRACT: Raised bogs have accumulated more atmospheric carbon than any other terrestrial ecosystem on Earth. Climate-induced expansion of trees and shrubs may turn these ecosystems from net carbon sinks into sources when associated with reduced water tables. Increasing water loss through tree evapotranspiration could potentially deepen water tables, thus stimulating peat decomposition and carbon release. Bridging the gap between modelling and field studies, we conducted a three-year mesocosm experiment subjecting natural bog vegetation to three birch tree densities, and studied the changes in subsurface temperature, water balance components, leaf area index and vegetation composition. We found the deepest water table in mesocosms with low tree density. Mesocosms with high tree density remained wettest (i.e. highest water tables) whereas the control treatment without trees had intermediate water tables. These differences are attributed mostly to differences in evapotranspiration. Although our mesocosm results cannot be directly scaled up to ecosystem level, the systematic effect of tree density suggests that as bogs become colonized by trees, the effect of trees on ecosystem water loss changes with time, with tree transpiration effects of drying becoming increasingly offset by shading effects during the later phases of tree encroachment. These density-dependent effects of trees on water loss have important implications for the structure and functioning of peatbogs.
    PLoS ONE 03/2014; 9(3):e91748. · 3.53 Impact Factor
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    ABSTRACT: The effectiveness of agri-environment schemes (AES) in enhancing biodiversity in agricultural landscapes is still strongly debated. In the Netherlands, one of the most widely implemented AES is the management of ditch banks to enhance plant species diversity. Previous research has shown that this type of AES has not led to increases in plant diversity. However, this work also showed that the success of this type of AES may depend on the presence of source populations in the surrounding areas. In this study we investigated if species-rich nature reserves can act as seed sources for agricultural ditch banks under AES and whether this function of nature reserves differs among plant species with different dispersal capacities. We used data collected by farmers over a 10 year period to analyse trends in species richness of target plants and in different dispersal groups in ditch banks under AES at different distances from nature reserves. Our results demonstrate that nature reserves can act as species rich sources in agricultural landscapes and that adjacent AES ditch banks can facilitate the colonisation of the surrounding agricultural landscape. However, the suitability of ditch banks as corridors depends on the dispersal capacity of a species. Particularly water-dispersed species clearly spread from nature reserves into the surrounding agricultural landscape along ditches. In contrast, species without adaptations to disperse over long distances do not show these spatiotemporal patterns.
    Biological Conservation 03/2014; 171:91–98. · 4.04 Impact Factor
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    ABSTRACT: Many of the agri-environment schemes (AES) implemented in the Western Peat District of the Netherlands have as their objective the conservation of the diversity of ditch bank plants. We investigated the effects of AES on ditch bank species in this area, using a dataset collected by 377 farmers who managed and monitored ditch banks during a 10-year period. We found that species richness has increased minimally over the last 10 years in ditch banks. Yet, we found no differences in increases in time between ditch banks with and without AES. In both ditch bank types plant species composition changed to species with higher nitrogen tolerance. Furthermore, species that disperse over long distances by water increased, whereas species with no capacity to disperse over long distances declined in both ditch bank types. This indicates that changes in vegetation composition in ditch banks are affected by other factors than AES.ZusammenfassungViele der Naturschutzprogramme für die Agrarlandschaft (AES), die in den westlichen Torfmoorgebieten der Niederlande zum Einsatz kommen, setzen sich zum Ziel, die Diversität der Uferpflanzen in Gräben zu erhalten. Wir untersuchten die Auswirkungen der AES auf die Arten der Ufer von Gräben in diesem Gebiet, und nutzten dafür einen Datensatz, der während einer 10-Jahresperiode von 377 Landwirten gesammelt wurde, welche die Grabenufer managten und erfassten. Wir haben herausgefunden, dass der Artenreichtum an den Grabenufern in den letzten zehn Jahren minimal zunahm. Dennoch fanden wir keinen Unterschied in der Zunahme zwischen den Grabenufern mit und ohne AES. Bei beiden Grabenufertypen veränderte sich die Pflanzenartenzusammensetzung hin zu Arten mit einer höheren Stickstofftoleranz. Darüber hinaus nahmen die Arten zu, die sich über weite Distanzen mit dem Wasser verbreiten, während Arten, denen die Möglichkeit fehlt, sich über weite Distanzen auszubreiten, bei beiden Grabenufertypen abnahmen. Dies zeigt, dass die Veränderungen in der Vegetationszusammensetzung nicht durch die AES sondern durch andere Faktoren beeinflusst werden.
    Basic and Applied Ecology 06/2013; 14:289-297. · 2.39 Impact Factor
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    ABSTRACT: It is generally known that managed, drained peatlands act as carbon sources. In this study we examined how mitigation through the reduction of management and through rewetting may affect the greenhouse gas (GHG) emission and the carbon balance of intensively managed, drained, agricultural peatlands. Carbon and GHG balances were determined for three peatlands in the western part of the Netherlands from 2005 to 2008 by considering spatial and temporal variability of emissions (CO2, CH4 and N2O). One area (Oukoop) is an intensively managed grass-on-peatland, including a dairy farm, with the ground water level at an average annual depth of 0.55 m below the soil surface. The second area (Stein) is an extensively managed grass-on-peatland, formerly intensively managed, with a dynamic ground water level at an average annual depth of 0.45 m below the soil surface. The third area is an (since 1998) rewetted former agricultural peatland (Horstermeer), close to Oukoop and Stein, with the average annual ground water level at a depth of 0.2 m below the soil surface. During the measurement campaigns we found that both agriculturally managed sites acted as carbon and GHG sources but the rewetted agricultural peatland acted as a carbon and GHG sink. The terrestrial GHG source strength was 1.4 kg CO2-eq m-2 yr-1 for the intensively managed area and 1.0 kg CO2-eq m-2 yr-1 for the extensively managed area; the unmanaged area acted as a GHG sink of 0.7 kg CO2-eq m-2 yr-1. Water bodies contributed significantly to the terrestrial GHG balance because of a high release of CH4 and the loss of DOC only played a minor role. Adding the farm-based CO2 and CH4 emissions increased the source strength for the managed sites to 2.7 kg CO2-eq m-2 yr-1 for Oukoop and 2.1 kg CO2-eq m-2 yr-1 for Stein. Shifting from intensively managed to extensively managed grass-on-peat reduced GHG emissions mainly because N2O emission and farm-based CH4 emissions decreased. Overall, this study suggests that managed peatlands are large sources of GHG and carbon, but, if appropriate measures are taken they can be turned back into GHG and carbon sinks within 15 yr of abandonment and rewetting.
    Biogeosciences Discussions 06/2013; 10(6):9697-9738.
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    ABSTRACT: Management of ditch banks of agricultural fields is considered to be a promising and multifunctional application of agri-environment schemes (AES) on farmland. Our previous esearch has shown that in the Netherlands, there is a small increase in the number of target plant species of AES in ditch banks. However, the productivity and Ellenberg indicator value or nitrogen also increased. This suggests a change in species composition towards more competitive species. This is important, because management mainly focuses on restoring disturbance tolerant species that used to be common in meadows, rather than competitive dominants. In this study we use a large scale dataset of target species composition in ditch banks of nature reserves and ditch banks with and without AES over 10 years to monitor esults of functional plant species groups under these different management regimes. Our analyses show that plant functional type composition in ditch banks of agricultural fields ndeed shifted towards more competitive species over the last 10 years, independent of AES. In nature reserves, a similar increase in competitive species was observed. The shift owards more competitive species was reflected in the increase of the average height of he vegetation and the increase in species with a leafy canopy structure, whereas species with a semi-basal canopy structure were decreasing. We conclude that current AES does not increase the number of targeted disturbance tolerant species and that more disturbance such as more frequent mowing is required to obtain these species.
    Aspects of Applied Biology; 04/2013
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    ABSTRACT: Agri-environment schemes have been established in many European countries to counteract the ongoing decline of farmland birds. In this study, the selection of foraging habitat by breeding skylarks was examined in relation to agri-environmental management on Dutch farmland. Field margin use was quantified and, based on the observed flight distances, the appropriateness of the current spatial arrangement of field margins in the study landscape was evaluated. Skylarks preferred field margins for foraging over all other habitat types relative to their surface area within the territories. The visiting rate of field margins decreased with increasing distance to the nest, and especially dropped markedly when the distance between the nest and a field margin exceeded 100 m. Analysis of the current spatial arrangement of field margins in the landscape suggested that the area of skylark breeding habitat within 100 m of a field margin could be increased by 46%. This was due to the placement of field margins alongside unsuitable breeding habitat and to the positioning of field margins at short distances from each other. The efficiency of agri-environmental management for skylarks can likely be improved by a more careful spatial arrangement of field margins in the landscape.
    Agriculture Ecosystems & Environment 04/2013; 170:10–15. · 3.20 Impact Factor
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    ABSTRACT: As biodiversity is declining at an unprecedented rate, an important current scientific challenge is to understand and predict the consequences of biodiversity loss. Here, we develop a theory that predicts the temporal variability of community biomass from the properties of individual component species in monoculture. Our theory shows that biodiversity stabilises ecosystems through three main mechanisms: (1) asynchrony in species' responses to environmental fluctuations, (2) reduced demographic stochasticity due to overyielding in species mixtures and (3) reduced observation error (including spatial and sampling variability). Parameterised with empirical data from four long-term grassland biodiversity experiments, our prediction explained 22-75% of the observed variability, and captured much of the effect of species richness. Richness stabilised communities mainly by increasing community biomass and reducing the strength of demographic stochasticity. Our approach calls for a re-evaluation of the mechanisms explaining the effects of biodiversity on ecosystem stability.
    Ecology Letters 02/2013; · 13.04 Impact Factor
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    ABSTRACT: To comprehend the potential consequences of biodiversity loss on the leaf litter decomposition process, a better understanding of its underlying mechanisms is necessary. Here, we hypothesize that positive litter mixture effects occur via complementary resource use, when litter species complement each other in terms of resource quality for detritivores. To investigate this, monocultures and mixtures of two leaf litter species varying in quality were allowed to decompose with and without a single macro-detritivore species (the terrestrial woodlice Oniscus asellus). Resource quality of the mixture was assessed by the mean concentration, the dissimilarity in absolute and relative concentrations, and the covariance between nitrogen (N), phosphorus (P) and calcium (Ca) supply. Our results clearly show that litter mixing effects were driven by differences in their resource quality for detritivores. In particular, complementary supply of N and P was a major driver of litter mixing effects. Interestingly, litter mixing effects caused by the addition of woodlice were predominantly driven by N dissimilarity, whereas in their absence, increased P concentration was the main driver of litter mixing effects. These results show that ultimately, litter diversity effects on decomposition may be driven by complementary resource use of the whole decomposer community (i.e., microbes and macro-detritivores).
    Oecologia 01/2013; · 3.25 Impact Factor
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    ABSTRACT: In recent decades, Skylark (Alauda arvensis) populations in Europe have declined sharply due to agricultural intensification. Insufficient reproduction rates are one reason. Increased winter mortality may also be important, but studies outside the breeding season are scarce and mostly limited to the UK. We studied habitat selection of wintering Skylarks in an agricultural area in the Netherlands. We monitored Skylarks between November 2008 and March 2009 on 10 survey plots including 77 different arable fields and permanent grasslands and covering in total 480 ha. We simultaneously measured food availability, vegetation structure and field boundary characteristics. We also analysed 158 faecal pellets collected on potato and cereal stubble fields to relate Skylark diet to seasonal changes in food availability and foraging habitat. We show that cereal stubble fields larger than 4.3 ha, surrounded by no or low boundary vegetation and a density of dietary seeds of more than 860 seeds m−2, were most suitable for wintering Skylarks. Skylark group densities were low on permanent grasslands and on maize stubble fields. Densities of dietary seeds were highest in soils of potato stubble fields followed by cereal stubble fields, grasslands and maize stubble fields. Skylarks showed a strong preference for cereal grains, but their proportion in the diet fell sharply at the end of November, indicating that cereal grains were depleted and birds had to switch to less profitable food sources, such as weed seeds and leaves. We conclude that Skylarks wintering in agricultural landscapes possibly suffer from a lack of energy-rich food sources and only a few fields provide sufficient food. Conservation measures should strive to improve the wintering situation by creating food-rich habitats such as over-winter stubble with a rich layer of weeds on large fields and localised in open areas.
    Journal of Ornithology. 01/2013;
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    ABSTRACT: Background/Question/Methods Nocturnal illumination leads to a permanent disturbance of natural habitats and there is accumulating evidence for – often negative – impact of artificial light in an increasing number of species. However, most of these studies are correlative and only include immediate or short-term effects of artificial light at the level of the individual while long-term consequences are still largely unknown. The current, worldwide change to LED outdoor lighting allows for custom-built spectra which can therefore be designed to minimize the negative impacts on flora and fauna. In order to experimentally assess short-term and long-term effects of artificial light with different spectra on the presence and the population density of species we have set up a large-scale monitoring experiment. We have put up 120 light posts at forest edges to illuminate natural habitats from sunset to sunrise with three different spectra: white light, and light with either reduced short or long wavelengths. The effect of the light is monitored for three years following a control year without light (2011); data are compared with control sites (dark) present throughout the experiment. Breeding birds, bats, other mammals, moths and vegetation are carefully monitored by specialized field biologists according to rigid protocols. In parallel, we experimentally test for effects of artificial light on the life history of birds and insects (moths) in separate in-depth studies. Changes in daily and seasonal timing, such as changes in onset of dawn chorus and laying date in birds are studied, and the effect of light on the herbivory and development of moth caterpillars. Results/Conclusions Artificial illumination of nest boxes with breeding great tits (Parus major) induces strong changes in chick provisioning behavior, which may be related to interference of nocturnal light with the assessment of time of year. The development of moth caterpillars (Mamestra brassicae) is profoundly affected by illumination at night. Our unprecedented monitoring experiment will provide key insights in how nocturnal illumination affects flora and fauna and how light spectra can be designed to minimize the negative effects.
    97th ESA Annual Convention 2012; 08/2012
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    ABSTRACT: European farmland bird populations have decreased dramatically in recent decades and agricultural intensification has been identified as the main cause contributing to these declines. Identifying which specific intensification pressures are driving those population trends seems vital for bird conservation in European farmland. We investigated the response of ground-nesting farmland birds to the multivariate process of agricultural intensification in six European countries covering a bio-geographical and intensification gradient. Supported by PCA analysis, two groups of factors, related to field management and landscape modification, were considered, seeking to discriminate the relative importance of the effects of these main intensification components. Variance partition analysis showed that landscape factors accounted for most of the variation of ground-nesting farmland bird individual and breeding pair densities, as well as Skylark (i.e. our single model species) individual densities. In the case of Skylark breeders, field factors were found to be more important to explain their density. Our results suggest that in general farmland bird densities as well as Skylark densities are higher in simple landscapes dominated by agriculture, but with smaller fields and more different crops on the farms. In addition, high yields were negatively related to bird densities. We conclude that while management actions aimed at farmland bird conservation taken at landscape level may exert a strong positive effect on overall bird densities, those taken at field level are also relevant, particularly for breeders and, therefore, may potentially influence the persistence of these species’ populations.
    Biological Conservation 04/2012; · 4.04 Impact Factor

Publication Stats

6k Citations
804.66 Total Impact Points

Institutions

  • 1995–2014
    • Wageningen University
      • • Department of Nature Conservation and Plant Ecology
      • • Nature Conservation and Plant Ecology Group
      Wageningen, Gelderland, Netherlands
  • 2011
    • VU University Amsterdam
      • Department of Ecological Science
      Amsterdamo, North Holland, Netherlands
    • Georg-August-Universität Göttingen
      • Department of Crop Sciences
      Göttingen, Lower Saxony, Germany
  • 2009
    • University of Zurich
      Zürich, Zurich, Switzerland
  • 1981–2000
    • Utrecht University
      • Division of Plant Ecophysiology
      Utrecht, Utrecht, Netherlands
  • 1999
    • University of Groningen
      • Laboratory of Plant Physiology
      Groningen, Province of Groningen, Netherlands