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The Synergism of Fire,
Forest Fragmentation and Selective Logging in the
Brazilian Amazon
Principle Investigator: Mark A. Cochrane
Human beings are changing the face of the globe at
unprecedented rates. This trend is especially clear
in the tropics where forests are being cleared at
the greatest absolute rate in history. However, the
actual impacts to tropical forests are being
underestimated since the impacts of such
disturbances as edge-related fragmentation effects,
selective logging and forest fires are poorly
quantified and largely overlooked in most
assessments.
Although frequently appearing innocuous, rainforest
fires are growing in size and frequency across the
tropics. These fires continually erode fragmented
forest edges. Such fires are unintended ecological
disturbances that transcend deforestation to degrade
vast regions of standing forest, diminishing
ecosystem services and economic potential of these
natural resources. Impacting the health of millions,
net tropical forest fire emissions may have released
carbon equivalent to 41% of world-wide fossil fuel
use in 1997-98. Episodically more severe during El
Niņo events, pan-tropical forest fires will increase
as more damaged, less fire-resistant, forests cover
the landscape. In the Brazilian Amazon, tropical
forest fires are a problem of rapidly growing
importance. Anthropogenic fire-use is now the
dominant forest disturbance in many regions of the
Amazon basin. Both forest fragmentation and
selective logging exacerbate the probability and
impact of these forest fires. The resultant changes
in the fire regime of these forests can create a
positive feedback in which successive fires become
both more likely and more severe. The consequences
of this altered disturbance regime may be the
irreversible eradication of many currently forested
areas with extreme repercussions upon regional
climate, biodiversity and socioeconomic
opportunities. Despite the importance of
uncontrolled forest fires, there is no basin-wide
knowledge of how much forest has burned in the
Amazon.
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The Center for Global Change & Earth Observations, Michigan
State University
218 Manly Miles Building, 1405 S. Harrison Road, East
Lansing, Michigan 48823, Phone: (517) 432-7774 |
