Secondary foest age of China (SFAC)

A national distribution of secondary forest age (SFA) is essential for understanding the forest ecosystem and carbon stock in China. While past studies have mainly used various change detection algorithms to detecting forest disturbance, which cannot adequately characterize the entire forest landscape. This study developed a data-driven approach for improving performances of the Vegetation Change Tracker (VCT) and Continuous Change Detection and Classification (CCDC) algorithms for detecting the establishment of forest stands. An ensemble method for mapping national-scale SFA by determining the establishment time of secondary forest stands using change detection algorithms and dense Landsat time series is proposed. A dataset of national secondary forest age for China (SFAC) for 1987 to 2020 and with a 30-m spatial resolution was produced from the optimal ensemble model. This dataset provides national, continuous spatial SFA information and can improve understanding of secondary forests and the estimation of forest carbon storage in China. The dataset presents the Secondary forest age (sfa) in china in 2020.The data includes 20 files named ‘’sfa_china_2020’’with tiff format in an zip. Values from 1 to 34 in the “Age” band represent the age of the forest, where values of 36 and 0 indicates a forest age > 34 (not a specific pixel-scale age) and non-forest, respectively. At the same time, the age of 34 to 1 prensents the year of forest regrowth ranged 1987 to 2020. The spatial extent of the dataset includes mainland China and Taiwan, but excludes the South China Sea islands. The map is defined in the WGS84 projection, has a 30-m spatial resolution.