The original data of China’s National Forest Continuous Inventory in the fourth phase of Hainan Island (in 2003, 2008, 2013 and 2018)

1. Original Data of Permanent Sample Plots in Hainan Province: The original data of 393 forest permanent sample plots in Hainan Island during the fourth phase of China’s National Forest Continuous Inventory (in 2003, 2008, 2013, and 2018), including Name of Arbor Groups, DBH, Altitude(m), Slope Direction, Slope Position, Slope Gradient(°), Soil Name, Soil Texture, Thickness of the Overburden Soil Layer(CM), Humus Thickness(cm), grain Thickness(cm), Vegetation Types, Shrub Coverage(%), Average Height of Shrubs(m), Herbage Coverage(%), Average Height of Herbage(m), Total Vegetation Coverage(%), Land Ownership, Forest Ownership, Power Level, Protection Level, Business Level.
2. Forest Stand Density in Hainan Island: The dominant arbor groups in 393 forest permanent sample plots, including DBH range, mean DBH and forest stand density, were investigated in four periods of China’s National Forest Continuous Inventory in Hainan Island (in 2003, 2008，2013 and 2018).

1. 海南省永久样地原始数据集：收录海南岛393个森林永久样地的中国第四次全国森林资源连续清查原始数据（调查年份为2003、2008、2013、2018年），涵盖以下调查指标：乔木组名称、胸径（DBH）、海拔（m）、坡向、坡位、坡度(°)、土壤名称、土壤质地、覆盖土层厚度（CM）、腐殖质层厚度（cm）、颗粒层厚度（cm）、植被类型、灌木盖度(%)、灌木平均高度(m)、草本盖度(%)、草本平均高度(m)、植被总盖度(%)、土地所有权、林木所有权、立地等级、保护等级、经营等级。
2. 海南岛林分密度数据集：针对海南岛393个森林永久样地内的优势乔木组，于中国第四次全国森林资源连续清查的四个调查周期（2003、2008、2013、2018年）开展调查，数据包含胸径范围、平均胸径及林分密度。