A meta-analysis of community response predictability to anthropogenic disturbances.

Disturbances often lead to changes in average values of community properties; however, disturbances can also affect the predictability of a community's response. We performed a meta-analysis to determine how response predictability, defined as among-replicate variance in diversity and community abundance, is affected by species removals, species invasions, nutrient addition, temperature increase, and habitat loss/fragmentation, and we further determined whether response predictability differed according to habitat and trophic role. Species removals and nutrient addition decreased response predictability, while species invasions increased response predictability. In aquatic habitats, disturbances generally led to a decrease in response predictability, whereas terrestrial habitats showed no overall change in response predictability, suggesting that differences in food web and ecosystem structure affect how communities respond to disturbance. Producers were also more likely to show decreases in response predictability, particularly following species removals, highlighting widespread destabilizing effects of species loss at the producer level. Overall, our results show that whether disturbances cause changes in response predictability is highly contingent on disturbance type, habitat, and trophic role. The nature of changes in response predictability--for example, strong decreases following species invasions and increases following species removals--will likely play a major role in how communities recover from disturbance.