Using Model Simulation to Quantify the Role of Dung Beetle in Dung C and N Decomposition.

We attempted to use the DCDN and DK C&N models to get quantitative understanding of the role of dung beetles in the processes of carbon and nitrogen decomposition, including production of greenhouse gases, of dungs from grazing animals. The field experiment was set up in a meadow in Nebraska Sandhills with a semi-arid climate. The grazing treatment includes high stocking density, low sticking density and haying. Major field measurements include locations and mass production of dungs by grazing animals, amount and activities of dung beetles, carbon and nitrogen mineralization and production of greenhouse gases from dungs, soil moisture, temperature and Eh at different depths, and daily weather data. We will report results of simulations using the DNDC and the DK C&N models on carbon and nitrogen decomposition and their comparison with observed data and discuss the roles of beetles in those processes.