Ecological determinism in plant community structure across a tropical forest landscape

• Published in: Ecology (Durham) Vol. 85; no. 9; pp. 2526 - 2538
• Main Authors: Svenning, J.C, Kinner, D.A, Stallard, R.F, Engelbrecht, B.M.J, Wright, S.J
• Format: Journal Article
• Language: English
• Published: Washington, DC Ecology Society of America 01-09-2004; Ecological Society of America
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Barro Colorado Island; Biodiversity; Biological and medical sciences; dispersal limitation; Ecology; Flowers & plants; Fundamental and applied biological sciences. Psychology; General aspects; Hydrology; mesoscale plant distributions; niche differences; oligarchy hypothesis; partial RDA; plant community assembly; Rainforests; redundancy analysis; shade tolerance; spatial autocorrelation; tropical forest; variance decomposition; United States; North America; Colorado; America; Barro Colorado Island; Panama; Community structure; redundancy analysis; Landscape; Plant community; Redundancy; niche differences; Tolerance; partial RDA; spatial autocorrelation; Ecology; Tropical forest; shade tolerance; Island; Dispersion; mesoscale plant distributions; Plant; Mesoscale; dispersal limitation; Barro Colorado Island; Ecological niche; oligarchy hypothesis; plant community assembly; Autocorrelation; variance decomposition
• ISSN: 0012-9658; 1939-9170
• DOI: 10.1890/03-0396

The ecological mechanisms hypothesized to structure species-rich communities range from strict local determinism to neutral ecological drift. We assessed the degree of ecological determinism in tropical plant community structure by analyses of published demographic data; a broad range of spatial, historical, and environmental variables; and the distributions of 33 herbaceous species (plot size = 0.02 ha) and 61 woody species (plot size = 0.09 ha) among 350 plots in a 16-km2forest landscape (Barro Colorado Island, Panamá). We found a strong degree of cross-landscape dominance by a subset of species whose identities were predictable from sapling survivorship rates under shade. Using canonical ordination we found that spatial and environmental-historical factors were of comparable importance for controlling within-landscape variability in species composition. Past land use had a strong impact on species composition despite ceasing 100-200 years ago. Furthermore, edaphic-hydrological factors, treefall gaps, and an edge effect all had unique impacts on species composition. Hence, ecological determinism was evident in terms of both cross-landscape dominance and within-landscape variability in species composition. However, at the latter scale, the large portion of the explained variance in species composition among plots uniquely attributed to spatial location pointed to an equally important role for neutral processes.