According to an analysis of 240 independent studies by researchers at the Yale School of Forestry & Environmental Studies, most polluted or damaged ecosystems worldwide can recover within a lifetime if societies commit to their cleanup or restoration. Yale University writes: ” forest ecosystems recovered in 42 years on average, while ocean bottoms recovered in less than 10 years. When examined by disturbance type, ecosystems undergoing multiple, interacting disturbances recovered in 56 years, and those affected by either invasive species, mining, oil spills or trawling recovered in as little as five years. Most ecosystems took longer to recover from human-induced disturbances than from natural events, such as hurricanes.”
However, Yale researchers noted that there was a potential “pitfall”: the ecosystems analyzed may have been in a disturbed state when they were initially examined. “Many ecosystems across the globe that have experienced extinctions and other fundamental changes as a result of human activities, combined with the ongoing effects of climate change and pollution, are far removed from their historical, natural pristine state. Thus ecologists measured recovery on the basis of an ecosystem’s more recent condition. The study points out the need for the development of objective criteria to decide when a system has fully recovered.”
One of the key messages of the study is it will not take centuries or millennia for degraded ecosystems to recover. In turn, an increased effort to restore degraded areas is worthwhile. Oswald Schmitz, an ecology professor at the Yale School of Forestry & Environmental Studies and co-author of the meta-analysis said: “Restoration could become a more important tool in the management portfolio of conservation organizations that are entrusted to protect habitats on landscapes.” Holly Jones, co-author of the research added: “We recognize that humankind has and will continue to actively domesticate nature to meet its own needs. The message of our paper is that recovery is possible and can be rapid for many ecosystems, giving much hope for a transition to sustainable management of global ecosystems.”
The Yale University analysis focuses on seven ecosystem types, including marine, forest, terrestrial, freshwater and brackish. The study also looks at recovery from major “anthropogenic disturbances”: agriculture, deforestation, eutrophication, invasive species, logging, mining, oil spills, overfishing, power plants and trawling, as well as the interactions between these disturbances. Major natural disturbances, including hurricanes and cyclones, are also included.