Bison-prairie dog-plant interactions in a North American mixed-grass prairie.

摘要: Both bison and prairie dogs have multiple dramatic effects on grassland landscapes both are considered by many to be keystone herbivores. Numerous studies documented their independent or combined impact ecosystem processes, but there been few attempts simultaneously assess the individual interactive of where they co-occur. We began a long-term study in late 1994 Badlands National Park, South Dakota, USA, evaluate ecological consequences presence exclusion dogs, bison, both, upon various aspects plant community dynamics N cycling. Five different treatments were established at three separate mixed-grass sites park: (1) off dog colony with excluded, (2) continued utilization, (3) excluded use, (4) utilization (5) excluded. There differences aboveground biomass species composition between two off-colony among on-colony treatments, even after 3 years treatment imposition. However, was >2 times greater than sites, primarily due near elimination grasses colonies. Off-colony dominated grass species, resulting lower diversity, while several forb species. Net mineralization early growing season 4 colonies all exhibited net immobilization latter half season. The results this indicate distinct properties on- treatments. Whether these patterns represent relatively stable alternate states whether changes will emerge herbivore additional is considerable interest.