Any assessment of the persistence and viability of species of conservation concern on military installations requires models that can project the demographic consequences for those populations in response to military training or other land use. For our purposes here, we define a population model as any model which describes the changes over time of a population occupying a single installation and it's immediate surroundings (see Metapopulation models for regional models that address Managing species across multiple installations ). Military use of the land (e.g., tracked vehicle training) often alters the quantity, quality, and spatial distribution of habitat used by threatened and endangered species or other species of conservation concern. Thus is it necessary that the population model translate spatial and temporal variability in habitat quantity and quality into changes in the number of individuals or population density. Population density alone can be a misleading indicator of habitat quality and population viability, and the relationship between habitat quality and simple population density may have weak predictive power (Van Horne 1983, Maurer 1986). Therefore, it is also desirable that the translation between habitat and population dynamics occur through the relationship between habitat and demographic parameters like fecundity, dispersal success, breeding success, survivorship, etc., which in turn determine population dynamics and persistence or extinction. Finally, because of the spatially distributed and spatially heterogeneous nature of training activity on what are generally large spatially heterogeneous installations, it is important that the population models include an explicit consideration of the effects of spatial structure and landscape pattern on population dynamics.
We have developed a population model of this type for territorial migrant bird species, and we have implemented the model for two species of conservation concern: Henslow's sparrow (Ammodramus henslowii) at Fort Knox, Kentucky and Fort Riley, Kansas, and cerulean warbler (Dendroica cerulea) at the Department of Energy's Oak Ridge Reservation, Oak Ridge, Tennessee.
Maurer, B. A. 1986. Predicting habitat quality for grassland birds using density habitat correlations. J. Wildl. Manage. 50:556566.
Van Horne, B. 1983. Density as a misleading indicator of habitat quality. J. Wildl. Manage. 47:893901.
Return to the Model Categories page
Return to the Web Site Map
Return to Ecological Modeling home page