![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Abstract
Due to the close relationship between climate and plant phenology, changes in plant phenological patterns have been used as a surrogate of climate change. We analysed Moderate Resolution Imaging Spectroradiometer (MODIS) images to investigate the onset, offset and length of growing season, as well as spatial and inter-annual patterns of Normalized Difference Vegetation Index (NDVI) across six types of vegetation/land use in Taiwan. Regression models indicate that temperature was moderately to strongly related to NDVI for each of the six vegetation/land-use types (coefficients of determination (R 2) = 0.45–0.86). There was a 1–2 month lag time between changes in temperature and NDVI in the forests that are distributed in mid- to high-elevation areas, but not in low-elevation unirrigated fields, paddy fields and urban areas. The relationship between precipitation and changes in NDVI was only significant for unirrigated fields and urban areas (R 2 = 0.37–0.43). Growing season ended considerably earlier at low elevations than at high elevations, possibly because of the earlier start and more severe dry period in low-elevation areas, such that the length of the growing season was longer in the forests than in the unirrigated fields, paddy fields and urban areas.
Acknowledgements
This research was supported in part by grants from the National Science Council of Taiwan (NSC 96-2313-B-133-001). We thank Dr Jihn-Fa Jan for comments on earlier versions of the manuscript.