Spring and Autumn Phenological Variability across Environmental Gradients of Great Smoky Mountains National Park, USA

Mountainous regions exhibit complex phenological behavior influenced by climatic, vegetational, and topographic gradients. A study analyzing the Great Smoky Mountains National Park from 2000 to 2015 revealed that elevational effects significantly impact spring phenology more than moisture effects, with deciduous forests showing increased sensitivity to antecedent warm temperatures. The research used MODIS time series data of the Normalized Difference Vegetation Index (NDVI) and filtered for cover type, topography, and disturbance history to improve understanding of land surface phenology (LSP). Findings suggest possible cross-seasonal lag effects, such as accelerated green-up after cold Januarys and early brown-down following warm springs. Disturbances like hemlock woolly adelgid infestations and severe tornadoes weakened sensitivity to temperature and precipitation variations, while low-severity wildland fires had no discernable effect.

Norman, S., Hargrove, W., & Christie, W. (2017). Spring and Autumn Phenological Variability across Environmental Gradients of Great Smoky Mountains National Park, USA. Remote Sensing, 9(5), 407. https://doi.org/10.3390/rs9050407