Fragmented Rainforests Hold 40% Less Biomass

by David DeFranza, www.treehugger.com, December 10, 2009

Image credit: World Resources Institute Staff/Flickr

Deforestation, we know, contributes a significant amount of carbon to the atmosphere. Stopping deforestation and forest degradation is a major goal of the REDD program, to be discussed at COP15 and beyond.

New research, however, based on extensive computer modeling of Brazil's Atlantic Forest, shows that protecting remnants of rainforest may not be enough.

Forest fragments, the models found, have a higher mortality rate for trees, especially older, large, trees, which can reduce the forest's biomass by as much as 40%. This is a direct result of the unbalanced ratio between vulnerable forest edge and forest center that leads to thinning and slow degradation.

It's important to note that this is not a completely novel realization. A similar study, conducted by Stanford University, reached the same conclusions about the fragility of such forest compositions in August 2009.

However, this latest research poses some intimidating challenges for conservationists looking to preserve the islands of rainforest that remain. In the report, researchers explain that "it is important to be clear about the fact that we are losing more than just the deforested areas." They went on to say that:

It is a mistake to think only in terms of total area. We have to start thinking in terms of the spatial configuration of the remaining forest fragments as well.

There are, of course, many questions raised by these results, which must be verified with empirical evidence before they are confirmed. However, one thing is clear: Forest fragments do not perform in the same way continuous forest does.

Read more about deforestation:
Carbon Emissions From Amazon Deforestation Increase as Older Forest Cleared
Greenhouse Gas Emissions from Deforestation & Forest Degradation Overestimated by IPCC
10 Countries With the Highest Deforestation Rates in the World
New Google Earth Layer Shows Global Deforestation

Link:  http://www.treehugger.com/files/2009/12/fragmented-rainforests-hold-40-percent-less-biom