The Variation of Land Surface Phenology From 1982 to 2006 Along the Appalachian Trail

The gradients of the Appalachian Trail (A.T.) in elevations and latitudes provide a megatransect to study environmental variations in the eastern United States. This paper reveals patterns and trends of land surface phenology (LSP) in association with climatic variables within a corridor area along the A. T. We employed time-series data from Global Inventory Modeling and Mapping Studies and the Surface Observation and Gridding System between 1982 and 2006 to extract spatial and temporal variation patterns of LSP metrics and the correlations with meteorological parameters. The derived trends in LSP metrics indicate that the extended length of season mainly resulted from delayed end of season (EOS) across the study area. More significant change occurred in the northern segment than in the southern segment, which reflects latitudinal effects. We analyzed the relationship between LSP and longitude, latitude, elevation, local climatic variables, and large-scale climate oscillations. Delayed start of season in 1989 and advanced EOS in 1988 were observed responding to the La Nina episode during 1988-1989. This paper provides information about the effects of climate and topography on LSP along the Appalachian Mountain ridges.