Effects of elk and bison carcasses on soil microbial communities and ecosystem functions in Yellowstone, USA

Carrion is long recognized as important to scavengers. How carrion may affect soil microbial biodiversity and ecosystem processes in natural systems is comparatively unknown, but is important for the intersection of vertebrate food webs, below-ground processes and ecological heterogeneity. We assessed in situ soil and plant responses to wolf-killed mammal carrion in Yellowstone National Park, USA. Bison and elk carcasses increased soil respiration and vegetation nutrient concentration and the carcasses contain altered bacterial and fungal communities compared to control plots. The 'fingerprints' of soil microbial taxa associated with bison compared to elk carcasses differed considerably and taxa are found dependent upon abiotic gradients and soil properties. We found evidence that soil microbial community changes associated with carcasses may not be as generalizable as previously thought, which is important for a mechanistic understanding of the links between carrion and soil heterogeneity and potentially for applications in forensic science. This work demonstrates the importance of carrion studies in natural systems. Our findings show that carrion creates distinct ecological patterns that contribute to both above- and below-ground biological heterogeneity, linking carrion distribution dynamics with soil microbial biodiversity and ecosystem functions.