Wed, Aug 04, 2021:On Demand
Background/Question/Methods
The tropics host the greatest diversity of species on the planet, yet face grave threats from habitat destruction and environmental degradation. Protected areas have long been considered bastions for biodiversity, but cross-boundary human activities and tropical species’ high sensitivity could force species to concentrate in core areas causing changes in the spatial distribution of ecosystem functions. We investigated how tropical species’ distributions responded to three types of edges: 1) forest, 2) park boundary, and 3) road, while simultaneously assessing the influence of species’ distance to range edge and environmental gradients. We obtained occurrence data of camera-trapped ground-dwelling mammals and birds from 14 protected areas monitored by the Tropical Ecology Assessment and Monitoring (TEAM) Network. We employed a multi-species occupancy model to estimate each species’ occupancy as a function of camera-trap specific covariates for each protected area. We investigated variation in drivers of species richness among protected areas by plotting community-level effect sizes of each covariate as a function of TEAM site-level characteristics. Lastly, we assessed the relationships between population-specific edge effects and species attributes.
Results/Conclusions We found that forest protected areas experiencing greater hunting pressure and greater fragmentation showed stronger and more consistent forest edge effects in which species richness declined near forest edges. Individual populations tended to avoid forest and road edges, but preferred park boundary edges. Preference for park boundaries was particularly notable in protected areas surrounded by continuous forest rather than agricultural or patchily forested landscapes. Among species attributes, both ground-foraging birds and mammals were more sensitive to road edges compared to those foraging in other strata. Elevation was also a significant predictor of species richness. Species richness peaked at intermediate elevations and protected areas with larger elevational gradients showed stronger associations. We therefore demonstrated how anthropogenic threats may act on the spatial distribution of species richness in tropical forest protected areas and identified differential responses to anthropogenic edge types of tropical birds and mammals based on species attributes.
Results/Conclusions We found that forest protected areas experiencing greater hunting pressure and greater fragmentation showed stronger and more consistent forest edge effects in which species richness declined near forest edges. Individual populations tended to avoid forest and road edges, but preferred park boundary edges. Preference for park boundaries was particularly notable in protected areas surrounded by continuous forest rather than agricultural or patchily forested landscapes. Among species attributes, both ground-foraging birds and mammals were more sensitive to road edges compared to those foraging in other strata. Elevation was also a significant predictor of species richness. Species richness peaked at intermediate elevations and protected areas with larger elevational gradients showed stronger associations. We therefore demonstrated how anthropogenic threats may act on the spatial distribution of species richness in tropical forest protected areas and identified differential responses to anthropogenic edge types of tropical birds and mammals based on species attributes.