November 17, 2009
Reducing Emissions from Deforestation and Degradation [REDD] programs that include landowners will conserve more habitat and ensure greater ecosystem services function than programs that focus solely on protected areas, report researchers from the Woods Hole Research Center (WHRC), the Instituto de Pesquisa Ambiental da Amazônia (IPAM), and the Universidade Federal de Minas Gerais (UFMG).
REDD, a proposed climate change mitigation mechanism that would compensate developing countries for keeping their forests standing, has emerged from relative obscurity to become a focal point of climate change negotiations over the past four years. But in rising to prominence, REDD has also become increasingly controversial. Among the concerns is that REDD will bias conservation activities towards high-carbon landscapes, leaving low-carbon ecosystems open to development, to the detriment of biodiversity and other ecosystem services.
The authors, led by Claudia Stickler of WHRC, examined the potential of REDD to conserve ecosystems in the Xingu basin, an area of rainforest and dry tropical woodland known as cerrado in the southern Brazilian Amazon. While the cerrado stores less carbon than the adjacent rainforest — making it less of a candidate for REDD — it nonetheless plays an important role in watershed maintenance, serving as the source several major Amazon tributaries, including the Xingu river. The cerrado further supports a wealth of endemic plant and animal species.
But the cerrado is also suitable for intensive agriculture and cattle ranching. As such, the ecosystem is being lost at more than twice the rate of the Amazon rainforest, resulting in significant carbon dioxide emissions and harming its watershed functions, potentially undermining the very system that supplies water to farmers and ranchers in the region.
Modeling carbon stocks, river discharge, annual evapotranspiration, habitat quality, and water quality under under three legislation scenarios, Stickler and colleagues found that a carbon program which compensates avoided deforestation and forest restoration on private land would sequester more carbon (more than 200 times the avoided emissions) and provide better water services than a program that focuses on protected areas, riparian zones, and indigenous territories alone. Including private landowners in a REDD program would keep more forest standing — across a wider range of habitats — than a program that excluded them.
"We have demonstrated for a large-scale Amazon landscape that REDD could foster improved watershed function, and increase habitat quality and quantity (e.g., through increased forest connectivity and reduced edge effects)," the authors write. "The Xingu headwaters case study demonstrates that the ecological cobenefits of REDD are sensitive not only to the quantity of forests and woodlands remaining on the landscape, but also to their spatial distribution."
"These results also provide further support to a shift in conservation theory that posits that landscape level conservation approaches are likely to secure ecosystem integrity better than those focused solely on protected or 'core' areas."
The paper also includes a broader evaluation of co-benefits afforded by REDD. The authors found in most cases that REDD programs will boost carbon stocks and provide "substantial ecological cobenefits," especially in schemes that focus on slowing destruction and degradation of old growth forests. The notable exception came in programs that seek carbon stock enhancement through tree plantations.
"We need a balanced approach to REDD as we get into the details of how this mechanism will work," said co-author Dan Nepstad of WHRC in a statement. "Images of rainforests being razed for Eucalyptus plantations in the name of carbon are simply not helpful."
"There are reasons to be concerned about possible ecological damages that could be caused by REDD, and to make sure that those damages are kept to a minimum, but the overwhelming evidence points to enormous ecological benefits overall, especially if REDD programs are well-planned," added Stickler.