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Title (Primary) Species associations in a heterogeneous Sri Lankan dipterocarp forest
Author Wiegand, T.; Gunatilleke, S.; Gunatilleke, N.;
Journal American Naturalist
Year 2007
Department OESA;
Volume 170
Issue 4
Language englisch;
Keywords coexistence; habitat association; pair-correlation function; plant-plant interactions; point pattern analysis; tropical forest
Abstract We used point pattern analysis to examine the spatial distribution of 46 common tree species (diameter at breast height >10 cm) in a fully mapped 500×500-m tropical forest plot in Sinharaja, Sri Lanka. We aimed to disentangle the effect of species interactions (second-order effects) and environment (first-order effects) on the species' spatial distributions. To characterize first-order associations (segregation, overlap), we developed a classification scheme based on Ripley's K and nearest-neighbor statistics. We subsequently used heterogeneous Poisson null models, accounting for possible environmental heterogeneity, to reveal significant uni- and bivariate second-order interactions (regularity, aggregation and repulsion, attraction). First-order effects were strong; overall, 53% of all species pairs occupied largely disjoint areas (segregation), 40% showed partial overlap, and 6% overlapped. Only 5% of all species pairs showed significant second-order effects, but about half of the species showed significant intraspecific effects. Significant plant-plant interactions occurred mostly within 24 m and disappeared within 1520 m of the focal plant. While lack of significant species interactions suggests support for the unified neutral theory, species' observed spatial segregation does not support the assumptions of the neutral theory. The strong observed tendency of species to segregate may have supplementary effects on other processes promoting species coexistence.
ID 2424
Persistent UFZ Identifier
Wiegand, T., Gunatilleke, S., Gunatilleke, N. (2007):
Species associations in a heterogeneous Sri Lankan dipterocarp forest
Am. Nat. 170 (4), E77 - E95