Development of an ecological model for the Riding Mountain National Park elk population
The state of ecological integrity can be determined by assessing the viability of a species that is considered vital to the ecosystem (Woodley 1993). This study involved modeling the Riding Mountain National Park elk population and components, which influenced and impacted the viability of the elk population, thereby indicating the state of ecological integrity within RMNP. Main components included in the model were wolves, human harvest, bear predation and winter severity. The development of the model utilized the STELLA software. As well, data were gathered from RMNP, the Manitoba Department of Conservation and various studies. The data was used to build the formulae that were placed in the model and then run. Sensitivity runs were conducted by varying the values of human harvest rate on elk, bear predation rate of elk calves, the adult and yearling birth rate of elk, and the wolf population. As well, additional runs were also carried out to test the elk population. The results of the run with the initial values showed an elk population that is beginning to decline. As well, the sensitivity runs indicated that the elk population was sensitive to changes in the human harvest rate on elk, the bear predation rate on calves and the adult birth rate. The model results also indicated that elk population was not that sensitive to changes in the wolf population. As well, the effect of winter severity on the elk population was minimal. The sensitivity of the elk population to the human harvest rate component indicates that the viability of the elk population could be significantly influenced by increases in the harvest rate. Because this is the a component of the model that RMNP managers can influence because RMNP managers are involved in setting the regulated harvest rates outside RMNP, the results of the model runs are beneficial for developing management practices that will help manage this component to prevent it from compromising the viability of the elk and possibly the ecological integrity of RMNP.