Nonrandom Processes Maintain Diversity in Tropical Forests

• Published in: Science (American Association for the Advancement of Science) Vol. 311; no. 5760; pp. 527 - 531
• Main Authors: Wills, Christopher, Harms, Kyle E., Condit, Richard, King, David, Thompson, Jill, He, Fangliang, Muller-Landau, Helene C., Ashton, Peter, Losos, Elizabeth, Comita, Liza, Hubbell, Stephen, LaFrankie, James, Bunyavejchewin, Sarayudh, Dattaraja, H. S., Davies, Stuart, Esufali, Shameema, Foster, Robin, Gunatilleke, Nimal, Gunatilleke, Savitri, Hall, Pamela, Itoh, Akira, John, Robert, Kiratiprayoon, Somboon, de Lao, Suzanne Loo, Massa, Marie, Nath, Cheryl, Md. Nur Supardi Noor, Kassim, Abdul Rahman, Sukumar, Raman, Suresh, Hebbalalu Satyanarayana, I-Fang Sun, Tan, Sylvester, Yamakura, Takuo, Zimmerman, Jess
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 27-01-2006; The American Association for the Advancement of Science
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biodiversity; Biological and medical sciences; Degrees of freedom; Ecosystem; Ecosystems; Forest ecology; Forestry research; Fundamental and applied biological sciences. Psychology; Mortality; Pathogens; Plant populations; Population Density; Population Dynamics; Rainforests; Species; Species diversity; Survival analysis; Synecology; Terrestrial ecosystems; Trees; Trees - growth & development; Tropical Climate; Tropical forests; Species diversity; Population regulation; Size; Hardwood forest tree; Tropical forest; Biodiversity; Survival; Rare species
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1117715

An ecological community's species diversity tends to erode through time as a result of stochastic extinction, competitive exclusion, and unstable host-enemy dynamics. This erosion of diversity can be prevented over the short term if recruits are highly diverse as a result of preferential recruitment of rare species or, alternatively, if rare species survive preferentially, which increases diversity as the ages of the individuals increase. Here, we present census data from seven New and Old World tropical forest dynamics plots that all show the latter pattern. Within local areas, the trees that survived were as a group more diverse than those that were recruited or those that died. The larger (and therefore on average older) survivors were more diverse within local areas than the smaller survivors. When species were rare in a local area, they had a higher survival rate than when they were common, resulting in enrichment for rare species and increasing diversity with age and size class in these complex ecosystems.