When it comes to maintaining tropical biodiversity, there is no substitute for primary forests

Primary forests are irreplaceable for sustaining tropical biodiversity

Luke Gibson, Tien Ming Lee, Lian Pin Koh, Barry W. Brook, Toby A. Gardner, Jos Barlow,Carlos A. Peres, Corey J. A. Bradshaw, William F. Laurance, Thomas E. Lovejoy & Navjot S. Sodhi

Nature (2011) published online 14 September 2011

This new study conclusively proves that there is no substitute for primary forests when it comes to maintaining tropical biodiversity. Conversion of tropical forests for agriculture, timber production and other uses has produced vast, human-dominated landscapes which do not augur well for the future of tropical forests.

The researchers provide a global assessment of the impact of disturbance and land conversion on biodiversity in tropical forests. They used a meta-analysis of 138 studies. Under scanner were 2,220 pairwise comparisons of biodiversity values in primary forests (with little or no human disturbance) and disturbed forests. They found that biodiversity values were substantially lower in degraded forests. This varied considerably by geographic region, taxonomic group, ecological metric and disturbance type.

 Even after partly accounting for confounding colonization and succession effects due to the composition of surrounding habitats, isolation and time since disturbance, the researchers found  that most forms of forest degradation have an overwhelmingly detrimental effect on tropical biodiversity. The researchers conclude that their results clearly indicate that when it comes to maintaining tropical biodiversity, there is no substitute for primary forests.