@article{DePalmaAbrahamczykAizenetal.2016, author = {De Palma, Adriana and Abrahamczyk, Stefan and Aizen, Marcelo A. and Albrecht, Matthias and Basset, Yves and Bates, Adam and Blake, Robin J. and Boutin, C{\´e}line and Bugter, Rob and Connop, Stuart and Cruz-L{\´o}pez, Leopoldo and Cunningham, Saul A. and Darvill, Ben and Diek{\"o}tter, Tim and Dorn, Silvia and Downing, Nicola and Entling, Martin H. and Farwig, Nina and Felicioli, Antonio and Fonte, Steven J. and Fowler, Robert and Franzen, Markus Franz{\´e}n and Goulson, Dave and Grass, Ingo and Hanley, Mick E. and Hendrix, Stephen D. and Herrmann, Farina and Herzog, Felix and Holzschuh, Andrea and Jauker, Birgit and Kessler, Michael and Knight, M. E. and Kruess, Andreas and Lavelle, Patrick and Le F{\´e}on, Violette and Lentini, Pia and Malone, Louise A. and Marshall, Jon and Mart{\´i}nez Pach{\´o}n, Eliana and McFrederick, Quinn S. and Morales, Carolina L. and Mudri-Stojnic, Sonja and Nates-Parra, Guiomar and Nilsson, Sven G. and {\"O}ckinger, Erik and Osgathorpe, Lynne and Parra-H, Alejandro and Peres, Carlos A. and Persson, Anna S. and Petanidou, Theodora and Poveda, Katja and Power, Eileen F. and Quaranta, Marino and Quintero, Carolina and Rader, Romina and Richards, Miriam H. and Roulston, T'ai and Rousseau, Laurent and Sadler, Jonathan P. and Samneg{\aa}rd, Ulrika and Schellhorn, Nancy A. and Sch{\"u}epp, Christof and Schweiger, Oliver and Smith-Pardo, Allan H. and Steffan-Dewenter, Ingolf and Stout, Jane C. and Tonietto, Rebecca K. and Tscharntke, Teja and Tylianakis, Jason M. and Verboven, Hans A. F. and Vergara, Carlos H. and Verhulst, Jort and Westphal, Catrin and Yoon, Hyung Joo and Purvis, Andy}, title = {Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, doi = {10.1038/srep31153}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167642}, pages = {31153}, year = {2016}, abstract = {Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.}, language = {en} } @article{MayrPetersEardleyetal.2020, author = {Mayr, Antonia V. and Peters, Marcell K. and Eardley, Connal D. and Renner, Marion E. and R{\"o}der, Juliane and Steffan-Dewenter, Ingolf}, title = {Climate and food resources shape species richness and trophic interactions of cavity-nesting Hymenoptera}, series = {Journal of Biogeography}, volume = {47}, journal = {Journal of Biogeography}, number = {4}, doi = {10.1111/jbi.13753}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208101}, pages = {854-865}, year = {2020}, abstract = {Aim: Temperature, food resources and top-down regulation by antagonists are considered as major drivers of insect diversity, but their relative importance is poorly understood. Here, we used cavity-nesting communities of bees, wasps and their antagonists to reveal the role of temperature, food resources, parasitism rate and land use as drivers of species richness at different trophic levels along a broad elevational gradient. Location: Mt. Kilimanjaro, Tanzania. Taxon: Cavity-nesting Hymenoptera (Hymenoptera: Apidae, Colletidae, Megachilidae, Crabronidae, Sphecidae, Pompilidae, Vespidae). Methods: We established trap nests on 25 study sites that were distributed over similar large distances in terms of elevation along an elevational gradient from 866 to 1788 m a.s.l., including both natural and disturbed habitats. We quantified species richness and abundance of bees, wasps and antagonists, parasitism rates and flower or arthropod food resources. Data were analysed with generalized linear models within a multi-model inference framework. Results: Elevational species richness patterns changed with trophic level from monotonically declining richness of bees to increasingly humped-shaped patterns for caterpillar-hunting wasps, spider-hunting wasps and antagonists. Parasitism rates generally declined with elevation but were higher for wasps than for bees. Temperature was the most important predictor of both bee and wasp host richness patterns. Antagonist richness patterns were also well predicted by temperature, but in contrast to host richness patterns, additionally by resource abundance and diversity. The conversion of natural habitats through anthropogenic land use, which included biomass removal, agricultural inputs, vegetation structure and percentage of surrounding agricultural habitats, had no significant effects on bee and wasp communities. Main conclusions: Our study underpins the importance of temperature as a main driver of diversity gradients in ectothermic organisms and reveals the increasingly important role of food resources at higher trophic levels. Higher parasitism rates at higher trophic levels and at higher temperatures indicated that the relative importance of bottom-up and top-down drivers of species richness change across trophic levels and may respond differently to future climate change.}, language = {en} }