Active Forest Management in the Southeastern United States, 1987-2019 (0.25 degree)

This dataset shows the amount of land (percent area) in the southeastern United States where both clear cuts and forest thins occurred at the same location but on different dates. This type of forest management is characteristic of industrial forest plantations for loblolly pine (Pinus taeda) in the region. Clear cuts and thins were identified according to the algorithm published in Thomas et al. (2021), which was applied to 30 m Landsat multitemporal data (all images, with cloud masks applied) for every three years from 1987-2019 and summarized according to 0.25 degree grid cells as the percent of the total area. Areas are considered to be actively managed plantations if they were classified by the National Landcover Database (NLCD) products (2016 release) as evergreen, mixed forest, or woody wetlands prior to the harvest year and exhibit both of these harvest types. Results should be interpreted such that actively-managed plantations have occurred at that location at some point during the time period, but not necessarily the entire period, depending on land use transitions.  
Note that for 1987-2001, the VCT-based NACP North American Forest Dynamics Project: Forest Disturbance and Regrowth Data (Goward et al. 2012) (change year) was used as a predictor variable in place of the Global Forest Change product (Hansen et al. 2013) (loss year).

本数据集展示了美国东南部地区在特定地点因不同时间进行砍伐和森林疏伐而发生的土地面积（百分比面积）变化。此类森林管理方式是该地区以松树（Pinus taeda）为栽植对象的工业林场的典型特征。砍伐和疏伐的识别依据托马斯等人在2021年发表的算法，该算法应用于1987年至2019年每三年一次的30米Landsat多时相数据（所有图像，已应用云掩膜），并以0.25度网格单元为基准，总结为总面积的百分比。若在收获年份之前，该区域已被国家土地覆盖数据库（NLCD）产品（2016年版）归类为常绿林、混合林或木本湿地，且同时表现出这两种收获类型，则被视为积极管理的林场。结果应解读为，在特定时间段内，该地点曾发生积极管理的林场，但并非整个时间段，具体取决于土地利用转型。请注意，对于1987年至2001年，使用基于VCT的北美森林动态项目：森林干扰与再生长数据（戈沃德等，2012年）（变化年份）作为预测变量，代替全球森林变化产品（汉森等，2013年）（损失年份）。