Robustness of food webs whose structures have been shaped by extinctions in the past

• Extinctions of species might lead to changes in the trophic structure of food webs with consequences for the robustness of the webs. Using a theoretical approach we here investigate 1) how ‘natural’ extinctions of species in a variable environment affect the trophic structure of food webs and 2) which consequences these structural changes will have for the topological and dynamical robustness of the webs to further, future disturbances. We show that food webs whose structure have been shaped by extinctions in the past (disassembled webs) are structurally different and more robust to disturbances (species deletion and exposure to high levels of environmental variability) than food webs of equal size (number of species) that have not gone through a phase of disassembly. The increased robustness of the disassembled webs is due to the preservation of certain link structures, structures that have been found to promote topological and dynamical stability. Thus, our results suggest that ‘natural’ extinctions lead to changes in the trophic structure of food webs which make them more resistant to future perturbations.

Nyckelord

Extinction risks; food-web; stability; robustness; topology; network structure; disassembly

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vet (ämneskategori)

ovr (ämneskategori)