An international collaboration of researchers compiled data from over 100 studies comparing the biodiversity of primary forests (forests subjected to little or no human disturbance) with that of forests that are regenerating following degradation by agriculture, logging, and other human activities.
Their conclusion: forest degradation is detrimental to biodiversity.
“Some scientists have recently argued that degraded tropical forests support high levels of biodiversity,” said study lead-author Luke Gibson, researcher at the National University of Singapore, in a press release.
“Our study demonstrates that this is rarely the case.”
Worldwide, few primary forests remain unaltered by humans. In particular, Southeast Asia has suffered the highest rates of deforestation and the greatest loss in biodiversity as a result of population growth, and the change of land-use to favor plantations of oil palms and exotic plants.
“Southeast Asia emerged as a conservation hotspot and must be one of our top priority regions,” said study co-author Tien Ming Lee from the University of California, San Diego in the release.
The team found that forest land converted for agricultural use exhibited the most detrimental changes in biodiversity.
Secondary forests (forests that have rebounded after major disturbances) were also found to have notably lower biodiversity values than primary forests.
“There’s no substitute for primary forests,” said Gibson. “All major forms of disturbance invariably reduce biodiversity in tropical forests.”
“It is therefore essential to limit the reach of humans and to preserve the world’s remaining old-growth rainforests while they still exist. The future of tropical biodiversity depends on it.”
The study is called “Primary forests are irreplaceable for sustaining tropical biodiversity,” and was published online on Sept. 14 in the journal Nature.
