Numerous human activities, such as logging, fishing, pollution and the introduction of exotic species negatively impact ecosystems around the world. These negative impacts mean ecosystems lose species diversity, biomass production, carbon storage, and nutrient uptake. An important question is, how long does it take for ecosystems to recover from perturbations. The answer to this question can inform conservation policy and strategies and could help focus management resources.
In a recent PLoS ONE paper, Jones and Schmitz attempt to answer this question by reviewing 240 published studies that examine post-disturbance ecosystem diversity and function. While they report that many ecosystems recover on the order of decades and that this is likely more rapid than previously thought, there are some important caveats. First, is that only about half of the 240 studies report a recovered state and either they were not carried out long enough or there are certain types of disturbances or systems where recovery takes much longer. Second is that there are important differences among habitat types. For example benthic algal recovery to hurricanes or oil spills may take 2-10 years, while the recovery of tree diversity to logging may take 20 to 100 years (or more). Thirdly, different measures of ecosystems general resulted in differing recovery times. For example, bird populations may recover quite quickly to logging (likely because they are migratory), whereas soil microbial communities and processes may take many decades due to changes in the soil environment. Finally, the nature of the disturbance can be an important determinant of time to recovery. Logging and agriculture require the greatest recovery time, while large storms and oil spills appear to require relative little time.
While these results may give us a general picture of ecosystem recovery, the data they use highlight the importance of knowing how disturbance type affect recovery and how different ecosystem measures can alter recovery time estimates.
Jones, H., & Schmitz, O. (2009). Rapid Recovery of Damaged Ecosystems PLoS ONE, 4 (5) DOI: 10.1371/journal.pone.0005653