Tree Diversity in Tropical Rain Forests: A Validation of the Intermediate Disturbance Hypothesis
Jean-François Molino,*
Daniel Sabatier
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.
Institut de Recherche pour le Développement, c/o
Cirad-forêt, Campus International de Baillarguet, TA10/D, 34398 Montpellier Cedex 5, France.
*
To whom correspondence should be addressed. E-mail:
molino{at}mpl.ird.fr
