Abstract ID: 166

Effects of selective logging on tropical forest carbon, water, and energy cycles

We used biometric and micrometerological measurements to track changes in carbon stocks and fluxes following selective logging in a tropical rainforest of the Brazilian Amazon as part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). Measurements were made at the km 67 and km 83 LBA-ECO sites in Tapajos National Forest, Para. Measurements at both sites began before logging to establish the pre-logging baseline carbon balance. In 2001, the area including the km 83 study site was selectively logged using reduced-impact techniques such as careful planning and pre-harvest cutting of vines. The km 67 site was not logged and provided the experiment control. Measurements at both sites continued for at least 30 months after logging. The logging removed ~3.5 trees ha-1 containing about 10% of the above ground biomass and left 15 Mg ha-1 of slash on the forest floor to decompose. The logging destroyed 10-15% of the canopy, increasing the area of forest gaps by a factor of 3 over nearby undisturbed forest. Gross Primary Production (GPP) and respiration (R) declined at the logged site roughly in proportion to the fraction of canopy removed logging, whereas wood production (wood NPP) increased at the logged site relative to the unlogged site. The combined changes in GPP and wood NPP indicate that the logged forest allocated more carbon to growth compared to respiration than the unlogged forest, which would provide a mechanism for the forest to regain lost biomass.

Session:  Carbon - What has been learned and what further can be learned from a network of eddy covariance towers in Amazonia?.

Presentation Type:  Oral