A new research has determined that tropical forest that has regrown after clear-cutting can become almost as biodiverse as untouched forest, and are worth conserving.
According to a report in Nature News, by comparing preserved and regrown forest in Costa Rica, a team led by ecologist Robin Chazdon of the University of Connecticut in Storrs has found that 90 percent of tree species from the original landscape can also be found in secondary forest.
The results, presented at a tropical biodiversity symposium in Washington DC, suggest these regrown areas may be worthy of conservation, even though they were once cleared.
"You really need to be looking at this entire spectrum and trying to manage it all, not just focusing on the pristine biodiverse gems," said Thomas Lovejoy, biodiversity chair of the Heinz Center in Washington, DC.
The symposium, hosted by the Smithsonian Institution, brought together biologists, policymakers, and environmental organization representatives to address controversy arising from a 2006 paper.
In that, Joseph Wright of the Smithsonian Tropical Research Institute (STRI) in Balboa, Panama, and Helene Muller-Landau of the University of Minnesota in St Paul suggested that tropical extinctions may not be as dire as predicted.
As farmers migrate to cities, the study argues, forests may have a chance to recover from agricultural clearing.
One key question is whether these abandoned areas will be able to reassemble the same richness of species as the old primary forest.
Chazdon and her colleagues assessed tree biodiversity changes in northeastern Costa Rica by surveying 18 hectares of preserved old-growth forest and 11 hectares of secondary forest, which ranged from 10 to 45 years old.
When they looked for trees with a diameter greater than 10 centimeters, they found only 59 percent of the old-growth tree species in the regrown areas.
But, when they extended their search to seedlings and saplings, the number rose to 90 percent.