Linking dung beetle diversity and its ecological function in a gradient of livestock intensification management in the Neotropical region

In the coming decades, the rapid expansion of livestock production in highly biodiverse regions is likely to increase deforestation, threatening biodiversity and disrupting key ecological functions. However, the relationship between biodiversity and ecosystem function in tropical livestock-dominated landscapes is still poorly understood and empirically under-explored. We evaluated how livestock intensification affects different attributes of the dung beetle community (species richness, number of individuals, and biomass) and their impact to dung removal. The study was done in twenty 1-km(2) sites in the Yucatan Peninsula, Mexico. These sites were located within a heterogeneous region representing five different land management types ranging from tropical dry forest to high-yield cattle ranches, including traditional and silvopastoral systems. The most plausible diversity-function relationship was based on biomass, while species richness and number of individuals were less supported and had similarly shaped diversity-function relationships. We found that intensification of livestock management drastically reduced dung beetle biomass which affected the rate of dung removal. Our results also show that the loss of larger-sized dung beetle species following forest loss has an effect on the rate of dung removal. Nonetheless, the remarkable increase in abundance of small-sized species seems to compensate for potential losses of function in low-yield cattle farms, as in the case of traditional and silvopastoral systems. Although low- and medium-yield livestock landscapes harbour high species richness and similar dung removal rate versus forested sites, other community attributes such as biomass provide additional information in understanding the effects of management practices in the livestock-dominated landscape.