TY  - JOUR
A1  - Schneider, Florian D.
A1  - Brose, Ulrich
A1  - Rall, Björn C.
A1  - Guill, Christian
T1  - Animal diversity and ecosystem functioning in dynamic food webs
JF  - Nature Communications
N2  - Species diversity is changing globally and locally, but the complexity of ecological communities hampers a general understanding of the consequences of animal species loss on ecosystem functioning. High animal diversity increases complementarity of herbivores but also increases feeding rates within the consumer guild. Depending on the balance of these counteracting mechanisms, species-rich animal communities may put plants under top-down control or may release them from grazing pressure. Using a dynamic food-web model with body-mass constraints, we simulate ecosystem functions of 20,000 communities of varying animal diversity. We show that diverse animal communities accumulate more biomass and are more exploitative on plants, despite their higher rates of intra-guild predation. However, they do not reduce plant biomass because the communities are composed of larger, and thus energetically more efficient, plant and animal species. This plasticity of community body-size structure reconciles the debate on the consequences of animal species loss for primary productivity.
Y1  - 2016
U6  - https://doi.org/10.1038/ncomms12718
SN  - 2041-1723
VL  - 7
SP  - 3129
EP  - 3138
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Binzer, Amrei
A1  - Guill, Christian
A1  - Rall, Björn C.
A1  - Brose, Ulrich
T1  - Interactive effects of warming, eutrophication and size structure: impacts on biodiversity and food-web structure
JF  - Global change biology
N2  - Warming and eutrophication are two of the most important global change stressors for natural ecosystems, but their interaction is poorly understood. We used a dynamic model of complex, size-structured food webs to assess interactive effects on diversity and network structure. We found antagonistic impacts: Warming increases diversity in eutrophic systems and decreases it in oligotrophic systems. These effects interact with the community size structure: Communities of similarly sized species such as parasitoid-host systems are stabilized by warming and destabilized by eutrophication, whereas the diversity of size-structured predator-prey networks decreases strongly with warming, but decreases only weakly with eutrophication. Nonrandom extinction risks for generalists and specialists lead to higher connectance in networks without size structure and lower connectance in size-structured communities. Overall, our results unravel interactive impacts of warming and eutrophication and suggest that size structure may serve as an important proxy for predicting the community sensitivity to these global change stressors.
KW  - complex food webs
KW  - extinctions
KW  - generalists
KW  - global change
KW  - size structure
KW  - specialists
Y1  - 2016
U6  - https://doi.org/10.1111/gcb.13086
SN  - 1354-1013
SN  - 1365-2486
VL  - 22
SP  - 220
EP  - 227
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Allhoff, Korinna Theresa
A1  - Ritterskamp, Daniel
A1  - Rall, Björn C.
A1  - Drossel, Barbara
A1  - Guill, Christian
T1  - Evolutionary food web model based on body masses gives realistic networks with permanent species turnover
JF  - Scientific reports
N2  - The networks of predator-prey interactions in ecological systems are remarkably complex, but nevertheless surprisingly stable in terms of long term persistence of the system as a whole. In order to understand the mechanism driving the complexity and stability of such food webs, we developed an eco-evolutionary model in which new species emerge as modifications of existing ones and dynamic ecological interactions determine which species are viable. The food-web structure thereby emerges from the dynamical interplay between speciation and trophic interactions. The proposed model is less abstract than earlier evolutionary food web models in the sense that all three evolving traits have a clear biological meaning, namely the average body mass of the individuals, the preferred prey body mass, and the width of their potential prey body mass spectrum. We observed networks with a wide range of sizes and structures and high similarity to natural food webs. The model networks exhibit a continuous species turnover, but massive extinction waves that affect more than 50% of the network are not observed.
Y1  - 2015
U6  - https://doi.org/10.1038/srep10955
SN  - 2045-2322
VL  - 5
PB  - Nature Publ. Group
CY  - London
ER  -