RT Journal Article
SR Electronic
T1 Landscape heterogeneity buffers biodiversity of meta-food-webs under global change through rescue and drainage effects
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.06.03.131425
DO 10.1101/2020.06.03.131425
A1 Remo Ryser
A1 Myriam R. Hirt
A1 Johanna Häussler
A1 Dominique Gravel
A1 Ulrich Brose
YR 2020
UL http://biorxiv.org/content/early/2020/06/04/2020.06.03.131425.abstract
AB The impacts of habitat fragmentation and eutrophication on biodiversity have been studied in different scientific realms. Metacommunity research1–5 has shown that reduction in landscape connectivity may cause biodiversity loss in fragmentated landscapes. Food-web research addressed how eutrophication increases biomass accumulations at high trophic levels causing the breakdown of local biodiversity 6–9. However, there is very limited understanding of their cumulative impacts as they could amplify or cancel each other. Here, we show with simulations of meta-food-webs that landscape heterogeneity provides a buffering capacity against increasing nutrient eutrophication. An interaction between eutrophication and landscape homogenization precipitates the decline of biodiversity. We attribute our results to two complementary mechanisms related to source and sink dynamics. First, the “rescue effect” maintains local biodiversity by rapid recolonization after a local crash in population densities. Second, the “drainage effect” allows a more uniform spreading of biomass across the landscape, reducing overall interaction strengths and therefore stabilizing dynamics. In complex food webs on large spatial networks of habitat patches, these effects yield systematically higher biodiversity in heterogeneous than in homogeneous landscapes. Our meta-food-web approach reveals a strong interaction between habitat fragmentation and eutrophication and provides a mechanistic explanation of how landscape heterogeneity promotes biodiversity.Competing Interest StatementThe authors have declared no competing interest.