Gap Partitioning among Tropical Rainforest Trees

作者：JULIE SLOAN DENSLOW · 发表于：Biotropica · 年份：1980 · DOI：10.2307/2388156 · 被引用次数：910 · 研究领域：Ecology and Vegetation Dynamics Studies、Animal Ecology and Behavior Studies、Wildlife Ecology and Conservation

Published observations on adaptations for seed disperal and seedling establishment are consistent with the hypothesis that rainforest trees partition forest clearings as establishment sites for offspring. Gaps vary importantly in two ways. The size of the opening affects the microclimate of the gap and therefore the conditions for seedling establishment. For any individual tree, the frequency of occurrence of gaps of a particular size range affects the probability that its propagules will reach a gap of suitable size for germination and establishment. In most rainforests large gaps (involving the death of several trees) are probably more rare than small gaps (involving single trees or branches). Interspecific competition for establishment sites has resulted in adaptive compromises in the regeneration strategies of each species. Traits that increase the probability of establishing seedlings in gaps of a particular size range appear to lower establishment in gaps outside this size range. I suggest that the coexistence of many rainforest tree species is at least partially due to their partitioning of canopy gaps by size. Therefore the size-class frequercy distribution of gaps peculiar to a given rainforest is expected to influence the types and diversity of species present. Examination of vegetation data from New and Old World rainforests reveals many patterns consistent with this hypothesis. This framework provides a mechanism for predictive and experimental studies of competit...