Land-Cover Changes within and Adjacent to the National Parks of the Northeast Temperate Network.

摘要

The Northeast Temperate Network (NETN) was established by the United States National Park Service (NPS) to monitor ecological conditions in 12 park units with diverse cultural and natural resources in Maine, New Hampshire, Vermont, Massachusetts, Connecticut, New York, and New Jersey. The NETN is also coordinating activities of the NPS Inventory and Monitoring (I&M) program for the Appalachian National Scenic Trail (A.T.). The NETN, together with many other I&M networks, has identified landscape dynamics as a high-priority vital sign. Suburban sprawl, timber harvests and increasingly fragmented natural habitats are just a few of the factors outside of park boundaries that impact the ecosystems within the parks. Knowledge of historical trends of land-cover change, not only how much has changed but also where and when changes have occurred, can help resource managers establish a landscape context for the parks and a better understanding of how park ecosystems fit into the broader landscape, identify key resources and ecosystem stressors, as well as prioritize resource management efforts. The goal of this study was to provide essential baseline data to document how the landscape has changed in the vicinity of the selected NETN park units. The generalized land cover categories included urban, herbaceous vegetation, deciduous forest, coniferous forest, mixed forest, water, wetlands, regrowth forest and barren lands/bare rockface. The three primary objectives of this project were: 1. to document general land-cover types within and surrounding selected NETN National Parks for 3 time periods: the early 1970's, mid-1980's, and 2002; and 2. to quantify land-cover change within and adjacent to NETN parks using selected buffer areas for the three time periods. We employed Landsat remote sensing data to derive the land cover data for each of the time period.