@article{RyserHaeusslerStarketal.2019,
  author    = {Ryser, Remo and H{\"a}ussler, Johanna and Stark, Markus and Brose, Ulrich and Rall, Bj{\"o}rn C. and Guill, Christian},
  title     = {The biggest losers: habitat isolation deconsructs complex food webs from top to bottom},
  series = {Proceedings of the Royal Society of London : B, Biological sciences},
  volume    = {286},
  journal   = {Proceedings of the Royal Society of London : B, Biological sciences},
  number    = {1908},
  publisher = {Royal Society},
  address   = {London},
  issn      = {0962-8452},
  doi       = {10.1098/rspb.2019.1177},
  pages     = {8},
  year      = {2019},
  abstract  = {Habitat fragmentation threatens global biodiversity. To date, there is only limited understanding of how the different aspects of habitat fragmentation (habitat loss, number of fragments and isolation) affect species diversity within complex ecological networks such as food webs. Here, we present a dynamic and spatially explicit food web model which integrates complex food web dynamics at the local scale and species-specific dispersal dynamics at the landscape scale, allowing us to study the interplay of local and spatial processes in metacommunities. We here explore how the number of habitat patches, i.e. the number of fragments, and an increase of habitat isolation affect the species diversity patterns of complex food webs (alpha-,beta-,gamma-, diversities). We specifically test whether there is a trophic dependency in the effect of these two factors on species diversity. In our model, habitat isolation is the main driver causing species loss and diversity decline. Our results emphasize that large-bodied consumer species at high trophic positions go extinct faster than smaller species at lower trophic levels, despite being superior dispersers that connect fragmented landscapes better. We attribute the loss of top species to a combined effect of higher biomass loss during dispersal with increasing habitat isolation in general, and the associated energy limitation in highly fragmented landscapes, preventing higher trophic levels to persist. To maintain trophic-complex and species-rich communities calls for effective conservation planning which considers the interdependence of trophic and spatial dynamics as well as the spatial context of a landscape and its energy availability.},
  language  = {en}
}
@article{CeulemansGaedkeKlauschiesetal.2019,
  author    = {Ceulemans, Ruben and Gaedke, Ursula and Klauschies, Toni and Guill, Christian},
  title     = {The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system},
  series = {Scientific Reports},
  volume    = {9},
  journal   = {Scientific Reports},
  publisher = {Macmillan Publishers Limited},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-019-43974-1},
  pages     = {16},
  year      = {2019},
  abstract  = {Diverse communities can adjust their trait composition to altered environmental conditions, which may strongly influence their dynamics. Previous studies of trait-based models mainly considered only one or two trophic levels, whereas most natural system are at least tritrophic. Therefore, we investigated how the addition of trait variation to each trophic level influences population and community dynamics in a tritrophic model. Examining the phase relationships between species of adjacent trophic levels informs about the strength of top-down or bottom-up control in non-steadystate situations. Phase relationships within a trophic level highlight compensatory dynamical patterns between functionally different species, which are responsible for dampening the community temporal variability. Furthermore, even without trait variation, our tritrophic model always exhibits regions with two alternative states with either weak or strong nutrient exploitation, and correspondingly low or high biomass production at the top level. However, adding trait variation increased the basin of attraction of the high-production state, and decreased the likelihood of a critical transition from the high- to the lowproduction state with no apparent early warning signals. Hence, our study shows that trait variation enhances resource use efficiency, production, stability, and resilience of entire food webs.},
  language  = {en}
}