Robustness to secondary extinctions: Comparing trait-based sequential deletions in static and dynamic food webs
2011 (English)In: Basic and Applied Ecology, ISSN 1439-1791, Vol. 12, no 7, 571-580 p.Article in journal (Refereed) Published
The loss of species from ecological communities can unleash a cascade of secondary extinctions, the risk and extent ofwhich are likely to depend on the traits of the species that are lost from the community. To identify species traits that have thegreatest impact on food web robustness to species loss we here subject allometrically scaled, dynamical food web models toseveral deletion sequences based on species’ connectivity, generality, vulnerability or body mass. Further, to evaluate the relativeimportance of dynamical to topological effects we compare robustness between dynamical and purely topological models. Thiscomparison reveals that the topological approach overestimates robustness in general and for certain sequences in particular.Top-down directed sequences have no or very low impact on robustness in topological analyses, while the dynamical analysisreveals that they may be as important as high-impact bottom-up directed sequences. Moreover, there are no deletion sequencesthat result, on average, in no or very fewsecondary extinctions in the dynamical approach. Instead, the least detrimental sequencein the dynamical approach yields an average robustness similar to the most detrimental (non-basal) deletion sequence in thetopological approach. Hence, a topological analysis may lead to erroneous conclusions concerning both the relative and theabsolute importance of different species traits for robustness. The dynamical sequential deletion analysis shows that food websare least robust to the loss of species that have many trophic links or that occupy low trophic levels. In contrast to previousstudies we can infer, albeit indirectly, that secondary extinctions were triggered by both bottom-up and top-down cascades.
Place, publisher, year, edition, pages
Elsevier, 2011. Vol. 12, no 7, 571-580 p.
IdentifiersURN: urn:nbn:se:liu:diva-73611DOI: 10.1016/j.baae.2011.09.008ISI: 000299149700003OAI: oai:DiVA.org:liu-73611DiVA: diva2:475021
funding agencies|European Science Foundation||German Research Foundation| BR 2315/11-1 |2012-01-102012-01-102014-07-11