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MEDIA ADVISORY: Small-scale Logging Leads to Clear-cutting in Brazilian Amazon
David Sims
Science Writer
Institute for the Study of Earth, Oceans, and Space
(603) 862-5369

July 31, 2006

DURHAM, N.H. -- A team of scientists, led by Greg Asner of the Carnegie Institution’s Department of Global Ecology, and including Michael Keller of the USDA Forest Service and the University of New Hampshire, has discovered an important indicator of rain forest vulnerability to clear-cutting in Brazil. Their five-year study is the first to quantify the relationship between selective logging, where loggers extract individual trees from the rain forest, and complete deforestation, or clear-cutting. They found that 16 percent of rain forests, which had been selectively logged, were completely clear-cut within one year and 32 percent of logged areas were completely cleared within four years.

The results will be published during the week of July 31, 2006 in the on-line early edition of The Proceedings of the National Academy of Sciences (PNAS)* and comes on the heels of recent Brazilian legislation to regulate logging for better sustainability and the announcement by the Brazilian National Space Research Institute (INPE) to develop a remote sensing system to monitor logging in collaboration with the Brazilian non-governmental organization, IMAZON. The on-going work of the Carnegie-led team could bolster the long-term timber management goals and monitoring efforts of the government.

Says co-author Keller, an affiliate professor at the UNH Institute for the Study of Earth, Oceans, and Space, “We were surprised to find how rapidly selective logging led to complete deforestation. Hopefully, new satellite monitoring and a new enforcement structure currently being instituted in Brazil will change the pattern of land use.”

*“Condition and fate of logged forests in the Brazilian Amazon,” by Gregory P. Asner, Eben N. Broadbent, Paulo J. C. Oliveira, Michael Keller, David E. Knapp, and José N. M. Silva. This research was funded by NASA.

Contact Michael Keller by cell phone at +55-19-8124-3250, office +55-19-3429-4062, or by e-mail Contact Greg Asner at,, or by phone at 650-380-2828.