Spring and Autumn Phenological Variability across Environmental Gradients of Great Smoky Mountains National Park, USAReport as inadecuate


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


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Southern Research Station, US Forest Service, 200 W.T. Weaver Blvd, Asheville, NC 28804, USA





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Academic Editors: Geoffrey M. Henebry, Forrest M. Hoffman, Jitendra Kumar, Xiaoyang Zhang, Alfredo R. Huete and Prasad Thenkabail

Abstract Mountainous regions experience complex phenological behavior along climatic, vegetational and topographic gradients. In this paper, we use a MODIS time series of the Normalized Difference Vegetation Index NDVI to understand the causes of variations in spring and autumn timing from 2000 to 2015, for a landscape renowned for its biological diversity. By filtering for cover type, topography and disturbance history, we achieved an improved understanding of the effects of seasonal weather variation on land surface phenology LSP. Elevational effects were greatest in spring and were more important than site moisture effects. The spring and autumn NDVI of deciduous forests were found to increase in response to antecedent warm temperatures, with evidence of possible cross-seasonal lag effects, including possible accelerated green-up after cold Januarys and early brown-down following warm springs. Areas that were disturbed by the hemlock woolly adelgid and a severe tornado showed a weaker sensitivity to cross-year temperature and precipitation variation, while low severity wildland fire had no discernable effect. Use of ancillary datasets to filter for disturbance and vegetation type improves our understanding of vegetation’s phenological responsiveness to climate dynamics across complex environmental gradients. View Full-Text

Keywords: land surface phenology; MODIS; NDVI; PhenoCam; monitoring; landscape ecology; chilling degree days; growing degree days; legacy effects; biodiversity land surface phenology; MODIS; NDVI; PhenoCam; monitoring; landscape ecology; chilling degree days; growing degree days; legacy effects; biodiversity





Author: Steven P. Norman * , William W. Hargrove and William M. Christie

Source: http://mdpi.com/



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