Abstract ID: 309

Ecological Effects of Disturbance and Recovery Processes in Central Amazon Forests

Tree mortality and damage from natural disturbance in the Amazon varies from the slow standing death of a single tree, to the instant razing of patches larger than 100 ha from microburst blowdowns. Canopy recovery in the disturbed patches is dependent on the size, intensity, and return frequency of disturbance events. Changes in ecophysiological processes as a forest patch recovers from early to late successional stages is poorly understood. Studies carried out in the Central Amazon near Manaus have shed new light on a number of these ecological processes. First, using a combination of extensive forest inventory plots, satellite remote sensing analyses, and new field studies, we have developed tree mortality probability distributions functions including variability in disturbance size, intensity, and return frequency for a Central Amazon landscape. Ecological attributes of trees filling canopy gaps varied with the size of the disturbance, with the largest gaps exhibiting significant shifts in species composition, average wood density, and biomass density. Carbon cycling within individual trees also varied with patch disturbance state. Trees in mature patches (biomass steady-state) exhibited significantly lower woody biomass production efficiencies than trees recovering in recently disturbed sites that were aggrading in biomass. Results demonstrate interesting landscape-scale mosaics of forest structure and ecosystem processes.

Session:  Carbon - Forest dynamics, natural disturbance, and recovery. (A)

Presentation Type:  Oral