TY - JOUR A1 - Seifert, Linda I. A1 - Weithoff, Guntram A1 - Gaedke, Ursula A1 - Vos, Matthijs T1 - Warming-induced changes in predation, extinction and invasion in an ectotherm food web JF - Oecologia N2 - Climate change will alter the forces of predation and competition in temperate ectotherm food webs. This may increase local extinction rates, change the fate of invasions and impede species reintroductions into communities. Invasion success could be modulated by traits (e.g., defenses) and adaptations to climate. We studied how different temperatures affect the time until extinction of species, using bitrophic and tritrophic planktonic food webs to evaluate the relative importance of predatory overexploitation and competitive exclusion, at 15 and 25 A degrees C. In addition, we tested how inclusion of a subtropical as opposed to a temperate strain in this model food web affects times until extinction. Further, we studied the invasion success of the temperate rotifer Brachionus calyciflorus into the planktonic food web at 15 and 25 A degrees C on five consecutive introduction dates, during which the relative forces of predation and competition differed. A higher temperature dramatically shortened times until extinction of all herbivore species due to carnivorous overexploitation in tritrophic systems. Surprisingly, warming did not increase rates of competitive exclusion among the tested herbivore species in bitrophic communities. Including a subtropical herbivore strain reduced top-down control by the carnivore at high temperature. Invasion attempts of temperate B. calyciflorus into the food web always succeeded at 15 A degrees C, but consistently failed at 25 A degrees C due to voracious overexploitation by the carnivore. Pre-induction of defenses (spines) in B. calyciflorus before the invasion attempt did not change its invasion success at the high temperature. We conclude that high temperatures may promote local extinctions in temperate ectotherms and reduce their chances of successful recovery. KW - Community dynamics KW - Freshwater ecosystem KW - Global warming KW - Species range shift KW - Trophic interactions Y1 - 2015 U6 - https://doi.org/10.1007/s00442-014-3211-4 SN - 0029-8549 SN - 1432-1939 VL - 178 IS - 2 SP - 485 EP - 496 PB - Springer CY - New York 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 -