A July 2009 article in the Christian Science Monitor (going through my old Delicious bookmarks, folks) noted that ecosystems may respond to restoration faster than previously thought.
Surveying 240 studies, scientists at the Yale School of Forestry & Environmental Studies found that the speed of recovery depended upon the type of ecosystem and the growth rate of the organisms within it. Forests recovered within 42 years, but ocean floors in less than a decade. Polluted ecosystems–those plagued by oil spills, mining, trawling, or invasive species–could recover in just five years. Only 15 percent were deemed beyond recovery.
The findings seem to contradict the popular notion that ecosystems take centuries or even millenniums to recover–boosting the rationale for proactive conservation. (from “Ecosystems Respond Well to Restoration” by Moises Velaquez-Manoff, Christian Science Monitor, July 13, 2009)
Of course, we don’t know what definition of restoration was used in the study, which was published in the journal PLos ONE.