This Cooperative Agreement between the National Park Service (NPS) and Syracuse University (SU) sets forth the roles and responsibilities of the parties regarding the collection and analyses of scientific data that replicate previous work conducted by SU to evaluate the effects of ungulates on soil and
plant systems across the northern range of which most of this geographic area is located in Yellowstone National Park (YNP).
The northern range has been described by Houston (1982) and Barmore (2003) in their early studies of ungulate / range relationships.
The NPS and SU recognize the need to continue to monitor the ecological relationships between the ungulate community and the ranges that they occupy.
Biogeochemical effects of predators preying on grazers indirectly influence the plant community by affecting the number of grazers in the system.
Elk populations declined following the wolf reintroduction in 199 5. While at the same time the bison population has increased to all time high levels.
The overall effects of these grazers recycling nutrients by turning plant biomass in to recycled nitrogen and carbon and providing nutrients for the plant communities is a natural function of dynamic systems we refer to as ecosystem processes.
The decline in grazing pressure by elk on the northern range in the late 1990s reduced plant production.
Changes in the ungulate community likely have altered range production and soil nitrogen processes.
Preservation of these natural processes is a fundamental part of the NPS mission.
An important management question that has been raised involves the role bison now play as a significant component of the grazing influence on grassland dynamics across the northern range of Yellowstone.