| The resources in the national parks of the United States are increasingly threatened from sources outside their boundaries, yet adequate documentation of the extent of these threats does not exist. Island biogeography theory suggests characteristics of a park may play a role in the extent to which a park is threatened. Because the threats are originating outside park boundaries, the socioeconomic setting of the park may also influence its threat status. The relationship between these external threats, characteristics of the park, and characteristics of park surroundings were assessed using discriminant function analysis. Parks were classified into a general ranked class framework for several categories of threats. Census data and map analysis were used to create variables describing each park and its matrix. Models were created to describe the relationships between the threat groupings and the variables describing each park and its surroundings. The models suggest that towns internal to, and immediately adjacent to park borders as well as the amount of natural area on the perimeter of a park are critical factors deserving further study. |
