Tree Diversity in Tropical Rain Forests: A Validation of the Intermediate Disturbance Hypothesis

• Published in: Science (American Association for the Advancement of Science) Vol. 294; no. 5547; pp. 1702 - 1704
• Main Authors: Molino, Jean-François, Sabatier, Daniel
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 23.11.2001; American Association for the Advancement of Science; The American Association for the Advancement of Science; American Association for the Advancement of Science (AAAS)
• Subjects: Analysis; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biodiversity; Biological and medical sciences; Biological diversity; Community Relations; Ecosystem; Environmental Sciences; Forest canopy; Forest regeneration; Forest trees; Forestry; French Guiana; Fundamental and applied biological sciences. Psychology; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Germination; Independent Study; Light; Models, Biological; Muscular atrophy; Rain forest ecology; Rain forests; Rainforests; Reproducibility of Results; Seasons; Seeds - physiology; Soil; Species diversity; Stems; Sunlight; Synecology; Terrestrial ecosystems; Time Factors; Trees; Trees - growth & development; Trees - physiology; Tropical Climate; Tropical forests; Tropical rain forests; South America; French Guiana; America; Species diversity; Light effect; Silviculture; Tropical zone; Tropical rain forest; Canopy gap; Species richness; Disturbed ecosystem; Guyane Francaise; French Guiana; Gaps; Neotropical forests
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1060284

The "intermediate disturbance hypothesis," which postulates maximum diversity at intermediate regimes of disturbance, has never been clearly proved to apply to species-rich tropical forest tree communities and to local-scale canopy disturbances that modify light environments. This hypothesis was tested on a sample of 17,000 trees in a Guianan forest, 10 years after a silvicultural experiment that added to natural treefall gaps a wide range of disturbance intensities. Species richness, standardized to eliminate density effects, peaked at intermediate disturbance levels, particularly when disturbance intensity was estimated through the percentage of stems of strongly light-dependent species.