Wed, Aug 04, 2021:On Demand
Background/Question/Methods
Species distributions are shaped in part by biotic interactions with other species, which can affect the extent to which pairs of species occupy the same areas and therefore co-occur. Novel anthropogenic influences may also affect species co-occurrence patterns and thereby alter ecological dynamics. Species with similar functional traits often require similar resources, which can lead to aggregation in locations where resources are available. However, competition for similar resources can lead to the exclusion of one species by another and may result in spatial segregation. The distribution and quantity of resource availability is often associated with environmental characteristics of the system, like primary productivity and habitat heterogeneity, but can also be altered by anthropogenic disturbance. Therefore, differences in anthropogenic disturbance, primary productivity and habitat heterogeneity may influence patterns of segregation and aggregation among mammals through their functional traits. Using a Bayesian framework, we investigated the co-occurrence strength of 1,242 mammal species pairs from 14 tropical forest protected areas as a function of species functional traits (e.g. body size, diet, activity period etc.) and park-level measurements of primary productivity, habitat heterogeneity and human density, while controlling for functional diversity.
Results/Conclusions We found that functionally similar species were more likely to co-occur in parks with high human densities than in parks with low human density. This effect was stronger than the effects of primary productivity and habitat heterogeneity, which were associated with lower species co-occurrence overall and for functionally similar species. Our results indicate that anthropogenic presence may increase the strength of co-occurrence for functionally similar mammal species in protected tropical forests. We suggest further investigation of resource distributions and competition among mammals in tropical forests under anthropogenic disturbance to clarify the ecological processes underlying these patterns.
Results/Conclusions We found that functionally similar species were more likely to co-occur in parks with high human densities than in parks with low human density. This effect was stronger than the effects of primary productivity and habitat heterogeneity, which were associated with lower species co-occurrence overall and for functionally similar species. Our results indicate that anthropogenic presence may increase the strength of co-occurrence for functionally similar mammal species in protected tropical forests. We suggest further investigation of resource distributions and competition among mammals in tropical forests under anthropogenic disturbance to clarify the ecological processes underlying these patterns.