Abiotic niche partitioning and negative density dependence drive tree seedling survival in a tropical forest

• Published in: Proceedings of the Royal Society. B, Biological sciences Vol. 284; no. 1869; p. 20172210
• Main Authors: Johnson, Daniel J., Condit, Richard, Hubbell, Stephen P., Comita, Liza S.
• Format: Journal Article
• Language: English
• Published: England The Royal Society 20.12.2017; The Royal Society Publishing
• Edition: Royal Society (Great Britain)
• Subjects: Annual variations; Biodiversity; Coexistence; Density Dependence; Ecology; Ecosystem; Forests; Habitat Association; Herbivores; Longevity; Niche overlap; Niches; Panama; Performance prediction; Planting density; Population Density; Rainforest; Resource Niche Partitioning; Seedlings; Seedlings - growth & development; Shade; Size Dependence; Species; Species diversity; Survival; Topography; Trees - growth & development; Tropical Climate; Tropical Forest Dynamics; Tropical forests; Water availability; resource niche partitioning; shade; size dependence; tropical forest dynamics; habitat association; density dependence
• ISSN: 0962-8452; 1471-2954; 1471-2954
• DOI: 10.1098/rspb.2017.2210

In tropical tree communities, processes occurring during early life stages play a critical role in shaping forest composition and diversity through differences in species' performance. Predicting the future of tropical forests depends on a solid understanding of the drivers of seedling survival. At the same time, factors determining spatial and temporal patterns of seedling survival can play a large role in permitting species coexistence in diverse communities. Using long-term data on the survival of more than 45 000 seedlings of 238 species in a Neotropical forest, we assessed the relative importance of key abiotic and biotic neighbourhood variables thought to influence individual seedling survival and tested whether species vary significantly in their responses to these variables, consistent with niche differences. At the community level, seedling survival was significantly correlated with plant size, topographic habitat, neighbourhood densities of conspecific seedlings, conspecific and heterospecific trees and annual variation in water availability, in descending order of effect size. Additionally, we found significant variation among species in their sensitivity to light and water availability, as well as in their survival within different topographic habitats, indicating the potential for niche differentiation among species that could allow for species coexistence.