Understanding the processes that regulate the carbon and nitrogen cycles is an essential step in forecasting the effects of climate change. Some of these processes are driven by living organisms, and most research on this biotic component of nutrient cycling has focused on plants and microbes, as these abundant organisms sequester atmospheric carbon. However, theoretical studies have shown that animals may also play an important role in nutrient cycling: in fact, the amount of carbon sequestered or released through animal-mediated processes could be comparable to the CO2 emissions of large industrial nations. The role of animals in facilitating carbon and nutrient cycling may be especially important in nutrient-poor ecosystems with barren vegetation, such as the high-altitude dry steppe of San Guillermo National Park in the Argentine Andes. My research investigates how the activity of pumas, vicu'as, and scavengers impacts carbon and nutrient cycling in San Guillermo. Specifically, I will be studying the effects of carcass deposition (predation) on soil nutrients, and testing whether scavenger activity mediates the flow of nutrients from carcasses to soil. I will also assess the indirect effects of predation on nutrient cycling, investigating how predation risk may influence herbivore movement and territoriality and how these behavioral patterns could be driving the flow of nutrients from hotspots to low productivity sites. Results from this study should inform our understanding of the biotic processes that drive carbon and nutrient cycling in this arid region, illuminating the potential cascading effects of animal species loss on primary productivity and climate change.