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Biometric Measures of Carbon Cycling Before, During, and After Selective Logging in Tapajós National Forest

Michela Figueira, CENA, Universidade de Sao Paulo, (Presenting)
Albert Sousa, IBAMA, Manaus, AM,
Augusto Maia, Universidade Federal do Para,
Mary Menton, IPAM, Santarem, PA,
Scott Miller, State University of New York at Albany,
Mike Goulden, University of California at Irvine,
Humberto Rocha, Universidade de Sao Paulo,

Long-term biometric measurements began in 2000 at the km 83 site of the Tapajos Forest that was selectively-logged in Fall 2001, and have continued to present. The measurements were focused in a 600 by 300-m block upwind of the eddy covariance tower, including leaf litterfall measured bi-weekly (30 litter traps), and 800 dendrometer bands (400 before logging and an additional 400 after logging) measured at 6 week intervals. Intensive tree surveys were also conducted before and after the selective logging. Litterfall varied seasonally from September 2000 to September 2001, with comparatively high rates beginning in May and continuing through the dry season. The May leaf drop preceded the beginning of the dry season, implying that it was not a direct result of drought. The May increase coincided with a decline in daytime CO2 uptake measured by eddy covariance, indicating that both LAI and canopy photosynthesis decreased beginning in May. The integrated litterfall observations prior to logging suggest an overall LAI of 5, which agrees with independent assessments of LAI made by fisheye photography during the 2000 wet season. The dendrometer observations prior to the logging are being used to determine the seasonal pattern of stem increment in the absence of disturbance. The dendrometer observations following the logging are being used to gauge the regrowth of the forest, and to determine the relative impact of logging on tree growth in patches of intact forest vs gaps vs the edges of gaps.

Science Theme:  CD (Carbon Dynamics)

Presentation Type:  Poster

Abstract ID: 44

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