A central goal of the U.S. National Park Service (NPS) is to maintain ecological functioning and native species within National Parks. While the attention of park managers is often on important near-term, in-park challenges, they also face maintaining parks under long-term and broad-scale change in climate and land use in and around parks. Land use in areas adjacent to parks is intensifying and some parks have identified recent losses in biodiversity or increased pressure on ecosystems from outside influences. While climate change may be responsible for degradation of some protected areas, the predominate driver of biodiversity loss is likely human activity on the lands surrounding protected areas. Quantifying the range of recent past change in land use around parks will provide NPS managers with knowledge of which parks are most susceptible to future change and which land use metrics should be monitored. We quantified change in a set of land use variables measured within and around 57 of the largest national parks in the contiguous U.S. between 1900 and 2007. The variables included population density, home density, agricultural land, impervious surface area, land allocation, undeveloped area, and fragmentation metrics of undeveloped land. Results/Conclusions

Preliminary analyses show that, on average, population increased over 3000% and the number of housing units by 400% during this time period. Increases were especially high in the Rocky Mountains and the Pacific West. The amount of undeveloped land or land in very low housing densities decreased by 24% on average, while the area in exurban densities increased by over 1000%. Increases in exurban housing were consistently high across the U.S. The amount of land in agriculture surrounding parks increased on average by over 400% although most eastern regions saw declines in agriculture. The proportion of the landscape around parks covered by impervious surfaces was highest in the Pacific Southwest and around Everglades National Park. Further analyses will clarify trends in fragmentation of landscapes surrounding parks and which land use variables may be most meaningful in explaining trends in biodiversity indices.