Spatial and temporal patterns of seed attack and germination in a large-seeded neotropical tree species.

摘要

The effects of canopy openness and parent-offspring distance on the frequency and timing of Chlorocardium rodiei seed attack and germination were studied within a 15-ha plot of Guyanan tropical rain forest. Seeds were artificially dispersed beneathparent trees, in the understorey away from trees and in gaps. Analysing data from an 85-week (from early 1992) period of regular monitoring showed that the main spatial gradients, (canopy openness and distance to nearest adult conspecific) do not lead todifferences in the final number of seeds attacked by infesting scolytid beetles or rodents. The timing of beetle attack, however, varied along the distance gradient and this difference affords seeds at further distances a 'window' in which to germinateand produce a seedling before attack. Canopy openness was not a good predictor of rooting success, but distance was strongly associated with root and shoot formation success and the mean time to shoot formation. There was a strong negative effect of distance on the likelihood of a seed being colonised by scolytid beetles prior to removal by rodents and shoot failure was strongly associated with prior infestation. Results are discussed in relation to patterns and success of recruitment in C. rodiei.