In a rapidly changing world, it is critical to understand the environmental and anthropogenic factors that alter global distributions of biological diversity. Trait-based approaches can provide a solution by incorporating relevant ecological characteristics of species, such as physiology and resource acquisition strategies, but fine-scale observational data are required to make use of this approach at the local level. In understudied tropical systems, standardized observational data across sites are difficult to obtain for elusive and low abundance animals, particularly mammals, and so the forces that structure mammal communities remain uncertain. In this study, we leverage observational data from the largest tropical camera trap monitoring network in the world, the Tropical Ecology Assessment and Monitoring Network (TEAM), providing unprecedented fine-scale data on tropical forest mammals collected over a large spatial extent. We seek to answer how energy availability, biotic interactions, historical biogeography and human disturbance affect the functional structure of tropical large mammal communities within protected areas. We model the response of functional richness and functional dispersion to energetic (incoming solar radiation), biotic (species pool), historical (bioregion), and anthropogenic predictors (human density surrounding the protected area, fragmentation occurring around the protected area) using generalized linear modeling and use AIC model selection to identify the top model.
Results/Conclusions
We evaluated mammal communities from 13 TEAM sites in protected areas across the Neotropics, Africa and Asia. Our study finds that increased human disturbance through fragmentation predictably associates with decreases in functional dispersion (p = 0.00568), while delineated size of protected areas predicts functional richness in an area-function relationship (p = 0.00853). This indicates that humans are potentially altering the structure of functional traits in large mammal communities, even in protected area. Degree of disturbance and conservation decisions made by humans appear to be major indicators of multiple aspects of community structure, while we failed to detect a relationship between community structure and environmental or biotic factors. Further work is necessary to fully understand how these disturbances select for or against specific functional traits and species in the community.