Impact of cyber-invasive species on a large ecological network
Anna Doizy, Edmund Barter, Jane Memmott, Karen Varnham and Thilo Gross
Sci Rep 8, 13245, 2018
As impacts of introduced species cascade through trophic levels, they can cause indirect and counter-intuitive effects. To investigate the impact of invasive species at the network scale, we use a generalized food web model, capable of propagating changes through networks with a series of ecologically realistic criteria. Using data from a small British offshore island, we quantify the impacts of four virtual invasive species (an insectivore, a herbivore, a carnivore and an omnivore whose diet is based on a rat) and explore which clusters of species react in similar ways. We find that the predictions for the impacts of invasive species are ecologically plausible, even for large networks robust predictions for the impacts of invasive species can be obtained. Species in the same taxonomic group are similarly impacted by a virtual invasive species. However, interesting differences within a given taxonomic group can occur. The results suggest that some native species may be at risk from a wider range of invasives than previously believed. The implications of these results for ecologists and land managers are discussed.
Figure 1: The Flat Holm food web. Species are grouped according to their taxonomy: plant, invertebrate, bird, fungus and reptile. Left: The full system. The dots represent the species. Right: The simplified system. Numbers on nodes/links show the number of species/interactions that are aggregated in the formulation of the simplified system.