Author
Christof Schüepp
Other affiliations: University of Koblenz and Landau
Bio: Christof Schüepp is an academic researcher from University of Bern. The author has contributed to research in topics: Biodiversity & Species richness. The author has an hindex of 16, co-authored 22 publications receiving 3256 citations. Previous affiliations of Christof Schüepp include University of Koblenz and Landau.
Papers
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National University of Río Negro1, University of Würzburg2, Rutgers University3, National University of Comahue4, Swedish University of Agricultural Sciences5, Commonwealth Scientific and Industrial Research Organisation6, University of California, Berkeley7, Naturalis8, University of Leeds9, University of Calgary10, Hebrew University of Jerusalem11, ETH Zurich12, Lüneburg University13, National University of Tucumán14, Federal University of Ceará15, Federal University of Bahia16, Plant & Food Research17, Michigan State University18, Agriculture and Agri-Food Canada19, The Nature Conservancy20, University of Göttingen21, University of Queensland22, Cornell University23, University of Reading24, Stockholm University25, University of Vermont26, Lund University27, University of Koblenz and Landau28, University of Bern29, Jagiellonian University30, Universidad de las Américas Puebla31, University of California, Davis32
TL;DR: Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation.
Abstract: The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.
1,881 citations
University of New England (Australia)1, Spanish National Research Council2, National University of Río Negro3, University of Reading4, Plant & Food Research5, Rutgers University6, Commonwealth Scientific and Industrial Research Organisation7, University of Queensland8, Australian Bureau of Agricultural and Resource Economics9, Lund University10, Swedish University of Agricultural Sciences11, University of California, Davis12, University of Lisbon13, University of Brasília14, Naturalis15, National University of Tucumán16, University of Koblenz and Landau17, Federal University of Ceará18, United Nations19, ETH Zurich20, Federal University of Bahia21, University of Giessen22, University of Freiburg23, Wageningen University and Research Centre24, Hebrew University of Jerusalem25, American Museum of Natural History26, University of Bern27, Trinity College, Dublin28, Royal Holloway, University of London29, Jagiellonian University30, University of Agriculture, Faisalabad31, Universidad de las Américas Puebla32
TL;DR: It is shown that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use.
Abstract: Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25–50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.
620 citations
Daniel S. Karp1, Rebecca Chaplin-Kramer2, Timothy D. Meehan3, Emily A. Martin4 +153 more•Institutions (81)
TL;DR: Analysis of the largest pest-control database of its kind shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others.
Abstract: The idea that noncrop habitat enhances pest control and represents a win-win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win-win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
398 citations
University of Würzburg1, Lund University2, Swedish University of Agricultural Sciences3, Commonwealth Scientific and Industrial Research Organisation4, University of Reading5, Wageningen University and Research Centre6, University of Padua7, University of Rennes8, University of Salamanca9, Agrocampus Ouest10, Sant'Anna School of Advanced Studies11, Spanish National Research Council12, Aix-Marseille University13, University of Kiel14, University of Freiburg15, University of Jyväskylä16, University of Koblenz and Landau17, University of Marburg18, Technische Universität München19, University of Natural Resources and Life Sciences, Vienna20, National University of Río Negro21, Instituto Nacional de Biodiversidad22, University of Giessen23, University of Belgrade24, Institut national de la recherche agronomique25, University of Extremadura26, University of Bordeaux27, University of Bern28, CABI29, University of Göttingen30, Pir Mehr Ali Shah Arid Agriculture University31
TL;DR: In landscapes with high edge density, 70% of pollinator and 44% of natural enemy species reached highest abundances and pollination and pest control improved 1.7- and 1.4-fold respectively, suggesting that enhancing edge density in European agroecosystems can promote functional biodiversity and yield-enhancing ecosystem services.
Abstract: Managing agricultural landscapes to support biodiversity and ecosystem services is a key aim of a sustainable agriculture. However, how the spatial arrangement of crop fields and other habitats in landscapes impacts arthropods and their functions is poorly known. Synthesising data from 49 studies (1515 landscapes) across Europe, we examined effects of landscape composition (% habitats) and configuration (edge density) on arthropods in fields and their margins, pest control, pollination and yields. Configuration effects interacted with the proportions of crop and non-crop habitats, and species’ dietary, dispersal and overwintering traits led to contrasting responses to landscape variables. Overall, however, in landscapes with high edge density, 70% of pollinator and 44% of natural enemy species reached highest abundances and pollination and pest control improved 1.7- and 1.4-fold respectively. Arable-dominated landscapes with high edge densities achieved high yields. This suggests that enhancing edge density in European agroecosystems can promote functional biodiversity and yield-enhancing ecosystem services.
321 citations
TL;DR: A new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world is described and assessed.
Abstract: Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species Existing global databases of species’ threat status or population time series are dominated by charismatic species The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines We describe and assess a new database of more than 16 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – wwwpredictsorguk) We make site-level summary data available alongside this article The full database will be publicly available in 2015
196 citations
Cited by
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United Nations Environment Programme1, American Museum of Natural History2, Imperial College London3, Swansea University4, University College London5, National University of Cordoba6, Tel Aviv University7, Max Planck Society8, University of Oldenburg9, Microsoft10, University of Oxford11, University of Wisconsin–Eau Claire12
TL;DR: A terrestrial assemblage database of unprecedented geographic and taxonomic coverage is analysed to quantify local biodiversity responses to land use and related changes and shows that in the worst-affected habitats, pressures reduce within-sample species richness by an average of 76.5%, total abundance by 39.5% and rarefaction-based richness by 40.3%.
Abstract: Human activities, especially conversion and degradation of habitats, are causing global biodiversity declines. How local ecological assemblages are responding is less clear--a concern given their importance for many ecosystem functions and services. We analysed a terrestrial assemblage database of unprecedented geographic and taxonomic coverage to quantify local biodiversity responses to land use and related changes. Here we show that in the worst-affected habitats, these pressures reduce within-sample species richness by an average of 76.5%, total abundance by 39.5% and rarefaction-based richness by 40.3%. We estimate that, globally, these pressures have already slightly reduced average within-sample richness (by 13.6%), total abundance (10.7%) and rarefaction-based richness (8.1%), with changes showing marked spatial variation. Rapid further losses are predicted under a business-as-usual land-use scenario; within-sample richness is projected to fall by a further 3.4% globally by 2100, with losses concentrated in biodiverse but economically poor countries. Strong mitigation can deliver much more positive biodiversity changes (up to a 1.9% average increase) that are less strongly related to countries' socioeconomic status.
2,532 citations
TL;DR: The stresses bees are experiencing from climate change, infectious diseases, and insecticides are reviewed, with concern that the authors may be nearing a “pollination crisis” in which crop yields begin to fall.
Abstract: Bees are subject to numerous pressures in the modern world. The abundance and diversity of flowers has declined, bees are chronically exposed to cocktails of agrochemicals, and they are simultaneously exposed to novel parasites accidentally spread by humans. Climate change is likely to exacerbate these problems in the future. Stressors do not act in isolation; for example pesticide exposure can impair both detoxification mechanisms and immune responses, rendering bees more susceptible to parasites. It seems certain that chronic exposure to multiple, interacting stressors is driving honey bee colony losses and declines of wild pollinators, but such interactions are not addressed by current regulatory procedures and studying these interactions experimentally poses a major challenge. In the meantime, taking steps to reduce stress on bees would seem prudent; incorporating flower-rich habitat into farmland, reducing pesticide use through adopting more sustainable farming methods, and enforcing effective quarantine measures on bee movements are all practical measures that should be adopted. Effective monitoring of wild pollinator populations is urgently needed to inform management strategies into the future.
2,526 citations
National University of Río Negro1, University of Würzburg2, Rutgers University3, National University of Comahue4, Swedish University of Agricultural Sciences5, Commonwealth Scientific and Industrial Research Organisation6, University of California, Berkeley7, University of Leeds8, Naturalis9, University of Calgary10, Hebrew University of Jerusalem11, Lüneburg University12, ETH Zurich13, National University of Tucumán14, Federal University of Ceará15, Federal University of Bahia16, Plant & Food Research17, Michigan State University18, Agriculture and Agri-Food Canada19, The Nature Conservancy20, University of Göttingen21, University of Queensland22, Cornell University23, University of Reading24, Stockholm University25, University of Vermont26, Lund University27, University of Koblenz and Landau28, University of Bern29, Jagiellonian University30, Universidad de las Américas Puebla31, University of California, Davis32
TL;DR: Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation.
Abstract: The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.
1,881 citations
TL;DR: There are well-documented declines in some wild and managed pollinators in several regions of the world, however, many effective policy and management responses can be implemented to safeguard pollinators and sustain pollination services.
Abstract: Wild and managed pollinators provide a wide range of benefits to society in terms of contributions to food security, farmer and beekeeper livelihoods, social and cultural values, as well as the maintenance of wider biodiversity and ecosystem stability. Pollinators face numerous threats, including changes in land-use and management intensity, climate change, pesticides and genetically modified crops, pollinator management and pathogens, and invasive alien species. There are well-documented declines in some wild and managed pollinators in several regions of the world. However, many effective policy and management responses can be implemented to safeguard pollinators and sustain pollination services.
1,121 citations
TL;DR: A simpler view of the relationship between habitat distribution and species richness, the ‘habitat amount hypothesis’, is proposed, which replaces two predictor variables, patch size and isolation, with a single predictor variable, habitat amount, when species richness is analysed for equal-sized sample sites rather than for unequal-sized habitat patches.
Abstract: I challenge (1) the assumption that habitat patches are natural units of measurement for species richness, and (2) the assumption of distinct effects of habitat patch size and isolation on species richness. I propose a simpler view of the relationship between habitat distribution and species richness, the ‘habitat amount hypothesis’, and I suggest ways of testing it. The habitat amount hypothesis posits that, for habitat patches in a matrix of non-habitat, the patch size effect and the patch isolation effect are driven mainly by a single underlying process, the sample area effect. The hypothesis predicts that species richness in equal-sized sample sites should increase with the total amount of habitat in the ‘local landscape’ of the sample site, where the local landscape is the area within an appropriate distance of the sample site. It also predicts that species richness in a sample site is independent of the area of the particular patch in which the sample site is located (its ‘local patch’), except insofar as the area of that patch contributes to the amount of habitat in the local landscape of the sample site. The habitat amount hypothesis replaces two predictor variables, patch size and isolation, with a single predictor variable, habitat amount, when species richness is analysed for equal-sized sample sites rather than for unequal-sized habitat patches. Studies to test the hypothesis should ensure that ‘habitat’ is correctly defined, and the spatial extent of the local landscape is appropriate, for the species group under consideration. If supported, the habitat amount hypothesis would mean that to predict the relationship between habitat distribution and species richness: (1) distinguishing between patch-scale and landscape-scale habitat effects is unnecessary; (2) distinguishing between patch size effects and patch isolation effects is unnecessary; (3) considering habitat configuration independent of habitat amount is unnecessary; and (4) delineating discrete habitat patches is unnecessary.
882 citations