POST-LOGGING TREE MORTALITY AND MAJOR BRANCH LOSSES IN KIBALE FOREST, UGANDA

This study was undertaken to establish whether selective felling and the existence of large forest gaps influence the dynamics of tree and branch falls. Censuses of fallen trees and large branch falls in uncut, lightly cut and heavily cut forest tracts were conducted for 20 months. Dead-standing trees in the study compartments were enumerated only three times at 6-month intervals. In lightly cut forest, the densities of live and dead tree and branch falls were similar but monthly tree snaps were more than uproots. However, for heavily cut forest, total tree falls (snap + uproot) involved more live than dead trees. There were more live than dead tree snaps and the rate of tree uproots was low. in contrast to the above, the density of tree snaps and uproots in uncut mature forest was similar. For total tree falls and live tree or large branch falls, the heavily selectively cut forest exhibited higher rates than uncut and lightly cut forest tracts. The annual rates of live tree falls ha-1 were 1.30 for lightly cut, 3.30 for heavily cut and 1.74 for uncut mature forest. It appears that heavy logging increases tree mortality rates through falls where more live tree snaps than uproots are involved.