Droughts are intensifying across the globe1,2, with potentially devastating implications for freshwater ecosystems3,4. We used new network science approaches to investigate drought impacts on stream food webs and explored potential consequences for web robustness to future perturbations. The substructure of the webs was characterized by a core of richly connected species5 surrounded by poorly connected peripheral species. Although drought caused the partial collapse of the food webs6, the loss of the most extinction-prone peripheral species triggered a substantial rewiring of interactions within the networks’ cores. These shifts in species interactions in the core conserved the underlying core/periphery substructure and stability of the drought-impacted webs. When we subsequently perturbed the webs by simulating species loss in silico, the rewired drought webs were as robust as the larger, undisturbed webs. Our research unearths previously unknown compensatory dynamics arising from within the core that could underpin food web stability in the face of environmental perturbations.
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X.L. and C.G. were supported by Queen Mary University of London. X.L. was additionally supported by the Chinese Scholarship Council and C.G. was additionally supported by the Freshwater Biological Association. This paper is a contribution to Imperial College’s Grand Challenges in Ecosystems and the Environment initiative. The project was supported by a FBA/Natural Environmental Research Council (NERC) postdoctoral fellowship to M.E.L. and NERC grants NER/B/S/2002/00215 and NE/J02256X/1. We would like to thank P. Armitage, F. K. Edwards and R. Harris for their contribution to the original experimental project and J. M. Olesen for his comments on the manuscript.
The authors declare no competing financial interests.
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Lu, X., Gray, C., Brown, L. et al. Drought rewires the cores of food webs. Nature Clim Change 6, 875–878 (2016). https://doi.org/10.1038/nclimate3002
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