Selective logging may best way to preserve tropical forests, finds study; 76% of carbon and 85%-100% of animal, plant species present before selective logging are present afterwards
May 10, 2012
– Harvesting tropical forests for timber may not be the arch-enemy of conservation that it was once assumed to be, according to a new study led by a University of Florida researcher.
Selective logging may be one of the few feasible options left for conserving tropical forests given the huge financial incentives pushing tropical landholders to convert primary forests into cash-generating agricultural plantations.
The report analyzed data from more than 100 studies of tropical forests on three continents that had been harvested for timber. Results suggest that while biodiversity and carbon retention take a hit from selective logging, the losses are survivable and reversible to a degree if the forest is given adequate time to recover. The study appears in the online version of the journal Conservation Letters.
That’s not the case when forests are converted to rubber or palm oil plantations, said the study’s lead author, Jack Putz, a UF professor of biology. Once a forest is gone, it is hard to get it back in any semblance of its former glory.
“We aren’t advocates for logging,” he said. “We’re just acknowledging that it is a reality — and that within that reality, there is a way forward.”
The study found that on average, 85 to 100 percent of the animal and plant species diversity present before an initial harvest remained after the forests were selectively logged. Forests also retained 76 percent of their carbon after an initial harvest.
The authors concede that the reports they analyzed could be overly optimistic portrayals of forest health. They nevertheless maintain that even moderately well-managed forests provide valuable benefits, and that badly managed forests can recover many of their most valuable attributes over time.
The continued existence of indigenous people culturally bound to these forests depends on forest survival, Putz said. Other people benefit from the eco-services that forests provide like soil erosion control, carbon sequestration and habitat for wildlife.
The problem, he said, is that there are powerful economic forces driving developing nations to convert their forests to cash crops and cattle ranches. A forest sustainably managed for timber and biodiversity might earn $2,000 per acre every 20 to 30 years. In contrast, a palm oil plantation can bring in the same amount in less than a year.
But there are ways to tip the balance sheet in favor of conservation, according to the study.
Programs that root out illegal logging operations protect forests by raising the price of legitimately harvested timber, he said. And that makes sustainable logging a more economically viable option for cash-strapped nations. The study also suggests that climate change mitigation programs designed to prevent logging could be modified to include support for environmentally sustainable timber management plans.
Many conservation biologists and ecologists in developed countries north of the equator seem reluctant to get behind these policies in a public way, he said. A chronic lack of oversight has made programs that allow for selective logging a risky ecological proposition in the past. That makes people involved in conservation hesitant to be seen as aligning themselves with timber harvest in any capacity.
But logging is going to happen anyway, Putz said. “Conservationists should be working to make sure it is carried out in the most environmentally and socially responsible ways possible,” he said.