The relationship between dung beetle diversity and manure removal in forest and sheep grazed grasslands

The relationships and linkages between biodiversity and ecosystem processes are critical issues in ecology. Manure removal is an ecosystem process related to several ecological functions performed by dung beetles. However, there is little information on manure removal by beetles in temperate ecosystems of Mexico. Using a linear model based on species biomass, here we estimated the amount of manure that can be potentially removed by dung beetle species in temperate forests and grasslands with sheep herding. Then, we related the estimated amount of manure removed with attributes of dung beetle communities: species richness, diversity, evenness and functional diversity in forest and grasslands sites. We compared the amount of manure potentially removed at each habitat by all species of dung beetles and by beetle's food relocation strategies. Also, we used Generalized Additive Models (GAMs) to test the relationships between manure removal and community attributes. Our model estimated that five species remove most of the manure, and tunneler beetles remove higher amounts of manure in grasslands than in forest sites. GAMs revealed that manure removal is related to dung beetle species richness and evenness, but not to functional diversity. Therefore, it is relevant to promote rich dung beetle communities to maintain optimal ecosystem functions, both in native forest and livestock areas.