Forest resilience refers to the ability of a forest to withstand damage caused by disturbance events and recover to its pre-disturbance state. Highly resilient forests are buffered from degradation due to disturbance which helps to promote conservation of species, however, little is known about the specific factors which control resiliency in forests across the globe. Understanding these factors is essential for quantifying forest ecosystem services and overall forest health. In order to estimate the effect that different disturbances have on forest resilience, we conducted a meta-analysis of 164 articles that used a variety of different resilience metrics in response to an equally diverse set of disturbances across all types of biomes. We conducted a Web of Science search with the keywords “forests” and “resilience”, and removed papers that did not mention a specific study area, type of disturbance, or explicitly compare resilience metrics taken between a control site and a manipulated treatment site independent of the disturbance. From these papers we extracted geographic and climatic information of the study area, type of disturbance, treatment conditions, and the type and magnitude of resilience. Resilience was estimated as the difference in effect size between control and manipulated treatments.
Results/Conclusions
We gathered 730 different measures of resilience from the 164 articles, spanning a range of disturbances, treatments, measures of resilience, taxa, and biomes. The most common disturbance investigated was fire, with clear-cutting also pervasive in the literature. In general, areas that were more productive and had greater levels of moisture were more resilient to disturbance events than drier, less productive systems. Periodic stand level management of forests (thinning) around the world also conferred increased resiliency to disturbances, primarily fire and drought. Despite theory that suggests older primary forests with greater overall species diversity are more resilient to a variety of disturbance types, our meta-analysis did not find many studies that investigated the role of diversity on resilience. These results not only point out critical gaps in our understanding of forest ecosystem resilience, but also highlight the factors most likely influence forest integrity in the future. This may be valuable knowledge to help conserve and manage forests in a future where climate change is likely to increase the frequency and magnitude of disturbance events.