TREE DAMAGE AND ANNUAL MORTALITY IN A MONTANE FOREST IN MONTEVERDE, COSTA-RICA

In four hectares of primary montane wet forest in Monteverde, Costa Ri ca, 1403 live trees (>10 cm diameter at breast height) were censused f or major damage and mortality during a four-year period. Overall tree damage and mortality after four years was 15.9 trees ha(-1) yr(-1), wi th over 80 percent due to snapping of trunks and uprooting of whole tr ees. Of the 73 stems that snapped during the study interval, 20 regene rated live foliage from their broken seems. This resulted in an actual mortality rate of 12.7 trees ha(-1) yr(-1), or 2.2 percent, which is in the mid-range of annual tree mortality reported for other forests. Tree death occurred during all seasons of the year, but rates were hig hest during the wet season. Individuals of gap-colonizing species died at a higher rate than expected from their representation in the popul ation. This study suggests chat although montane sites are subject to high winds and unstable soils, overall rates and types of mortality ar e similar to lowland forest sites.