Frank et al. examined the effects of variable site condition and herbivory on net N mineralization, nitrification, denitrification and inorganic N, leaching inside and adjacent to 33-year or older exclosures, on the northern winter range in Yellowstone National Park, Wyoming. Significantly, greater net N mineralization and nitrification occurred per unit area on grazed sites and, simultaneously, grazing also reduced N loss from the soil. The authors suggest that this later result most likely stems from grazer promotion of microbial productivity. These soil 15N results suggest that ungulates inhibited N loss at the seven study sites. Such documented evidence for consumer control of N availability to plants, microbial productivity, and N retention in Yellowstone Park is further testimony for the widespread regulation of grassland processes by large herbivores.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.