Disturbance hypothesis.

Abstract

The disturbance hypothesis posits that the invasion success of non-native species is higher in highly disturbed than in relatively undisturbed ecosystems. A synonymous formulation is that highly disturbed ecosystems show lower resistance against nonnative species than relatively undisturbed ecosystems. On the basis of a systematic literature search, we identified 126 studies addressing the disturbance hypothesis. Applying the hierarchy-of-hypotheses approach, we classified these studies according to: (i) the cause of disturbance (direct anthropogenic vs indirect or non-anthropogenic disturbances); (ii) the type of disturbance; and (iii) the measure of invasion success. The majority of studies reported evidence supporting the disturbance hypothesis (59%, with 21% of the studies questioning the hypothesis and another 21% being undecided). Most subhypotheses were supported as well, only studies focusing on conservation management or fire as disturbances frequently reported questioning evidence. There was also consistent support for the hypothesis across taxonomic groups and terrestrial as well as aquatic systems. However, experimental field studies showed a lower level of support than observational or laboratory studies. Overall, this hypothesis is relatively well, but not very strongly supported by currently available studies. Given that human disturbances will further increase in the foreseeable future, we can predict that these will tend to further promote biological invasion…