TY - JOUR A1 - Simons, Nadja K. A1 - Lewinsohn, Thomas A1 - Bluethgen, Nico A1 - Buscot, Francois A1 - Boch, Steffen A1 - Daniel, Rolf A1 - Gossner, Martin M. A1 - Jung, Kirsten A1 - Kaiser, Kristin A1 - Müller, Jörg A1 - Prati, Daniel A1 - Renner, Swen C. A1 - Socher, Stephanie A. A1 - Sonnemann, Ilja A1 - Weiner, Christiane N. A1 - Werner, Michael A1 - Wubet, Tesfaye A1 - Wurst, Susanne A1 - Weisser, Wolfgang W. T1 - Contrasting effects of grassland management modes on species-abundance distributions of multiple groups JF - Agriculture, ecosystems & environment : an international journal for scientific research on the relationship of agriculture and food production to the biosphere N2 - Intensive land use is a major cause of biodiversity loss, but most studies comparing the response of multiple taxa rely on simple diversity measures while analyses of other community attributes are only recently gaining attention. Species-abundance distributions (SADs) are a community attribute that can be used to study changes in the overall abundance structure of species groups, and whether these changes are driven by abundant or rare species. We evaluated the effect of grassland management intensity for three land-use modes (fertilization, mowing, grazing) and their combination on species richness and SADs for three belowground (arbuscular mycorrhizal fungi, prokaryotes and insect larvae) and seven aboveground groups (vascular plants, bryophytes and lichens; arthropod herbivores; arthropod pollinators; bats and birds). Three descriptors of SADs were evaluated: general shape (abundance decay rate), proportion of rare species (rarity) and proportional abundance of the commonest species (dominance). Across groups, taxonomic richness was largely unaffected by land-use intensity and only decreased with increasing mowing intensity. Of the three SAD descriptors, abundance decay rate became steeper with increasing combined land-use intensity across groups. This reflected a decrease in rarity among plants, herbivores and vertebrates. Effects of fertilization on the three descriptors were similar to the combined land-use intensity effects. Mowing intensity only affected the SAD descriptors of insect larvae and vertebrates, while grazing intensity produced a range of effects on different descriptors in distinct groups. Overall, belowground groups had more even abundance distribtitions than aboveground groups. Strong differences among aboveground groups and between above- and belowground groups indicate that no single taxonomic group can serve as an indicator for effects in other groups. In the past, the use of SADs has been hampered by concerns over theoretical models underlying specific forms of SADs. Our study shows that SAD descriptors that are not connected to a particular model are suitable to assess the effect of land use on community structure. KW - Biodiversity KW - Cutting frequency KW - Management intensity KW - Rank-abundance KW - Species loss KW - Rarity Y1 - 2017 U6 - https://doi.org/10.1016/j.agee.2016.12.022 SN - 0167-8809 SN - 1873-2305 VL - 237 SP - 143 EP - 153 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Curtsdotter, Alva A1 - Binzer, Amrei A1 - Brose, Ulrich A1 - de Castro, Francisco A1 - Ebenman, Bo A1 - Ekloef, Anna A1 - Riede, Jens O. A1 - Thierry, Aaron A1 - Rall, Bjoern C. T1 - Robustness to secondary extinctions comparing trait-based sequential deletions in static and dynamic food webs JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - The loss of species from ecological communities can unleash a cascade of secondary extinctions, the risk and extent of which are likely to depend on the traits of the species that are lost from the community. To identify species traits that have the greatest impact on food web robustness to species loss we here subject allometrically scaled, dynamical food web models to several deletion sequences based on species' connectivity, generality, vulnerability or body mass. Further, to evaluate the relative importance of dynamical to topological effects we compare robustness between dynamical and purely topological models. This comparison reveals that the topological approach overestimates robustness in general and for certain sequences in particular. Top-down directed sequences have no or very low impact on robustness in topological analyses, while the dynamical analysis reveals that they may be as important as high-impact bottom-up directed sequences. Moreover, there are no deletion sequences that result, on average, in no or very few secondary extinctions in the dynamical approach. Instead, the least detrimental sequence in the dynamical approach yields an average robustness similar to the most detrimental (non-basal) deletion sequence in the topological approach. Hence, a topological analysis may lead to erroneous conclusions concerning both the relative and the absolute importance of different species traits for robustness. The dynamical sequential deletion analysis shows that food webs are least robust to the loss of species that have many trophic links or that occupy low trophic levels. In contrast to previous studies we can infer, albeit indirectly, that secondary extinctions were triggered by both bottom-up and top-down cascades. KW - Species loss KW - Extinction cascades KW - Top-down effect KW - Bottom-up effect KW - Stability KW - Body size KW - Trophic interactions KW - Vulnerability KW - Generality KW - Keystone species Y1 - 2011 U6 - https://doi.org/10.1016/j.baae.2011.09.008 SN - 1439-1791 VL - 12 IS - 7 SP - 571 EP - 580 PB - Elsevier CY - Jena ER -