Forest structure drives global diversity of primates

Area of Science:

• Ecology
• Biodiversity Science
• Conservation Biology

Background:

• Primate species richness gradients are traditionally linked to forest productivity and precipitation.
• Previous global-scale analyses examining these drivers comprehensively are lacking.
• Alternative hypotheses regarding habitat structure have not been fully tested globally.

Purpose of the Study:

• To test the roles of precipitation, biomass production, and forest vertical structure in determining global primate species richness.
• To propose and evaluate forest canopy height as a key predictor of primate diversity.
• To investigate the direct and indirect relationships among these factors using a path framework.

Main Methods:

• Structural equation modeling was employed to analyze causal relationships.
• Global and continental-scale data on primate species richness, precipitation, biomass production, and forest canopy height were used.
• Spatial autocorrelation and biogeographical region differences were accounted for.

Main Results:

• Forest canopy height was a stronger predictor of primate species richness than precipitation or productivity globally and continentally.
• Precipitation was the dominant factor only in Asia, independent of productivity or structure.
• The influence of spatial processes varied significantly across biogeographical regions.

Conclusions:

• Forest vertical structure, indicated by canopy height, is a primary driver of primate species richness, surpassing traditional precipitation-based explanations.
• This challenges the rainfall-centric viewpoint, emphasizing habitat complexity and structure.
• Findings inform predictions regarding the impact of deforestation on primate diversity.