Productivity of U.S. Rangelands, Annual Data lbs/acre (Image Service)

Production data were generated using the Normalized Difference Vegetation Index (NDVI) from the Thematic Mapper Suite from 1984 to 2023 at 250 m resolution. The NDVI is converted to production estimates using two regression formulas depending on the level of the NDVI; there is one equation for lower values (and thus lower production values) and one for higher values. This raster dataset yields estimates of annual production of rangeland vegetation and should be useful for understanding trends and variability in forage resources. This raw lbs/acre data that the Z-scores were derived from as well as the Z-scores dataset can be downloaded from: https://data.fs.usda.gov/geodata/rastergateway/rangelands/index.php.本数据集的生产数据采用1984年至2023年期间、分辨率为250米的专题制图仪套件（Thematic Mapper Suite）所获取的归一化差分植被指数（Normalized Difference Vegetation Index，NDVI）生成。研究人员依据NDVI的数值区间，采用两套回归公式将其转换为植被生产估算值：一套针对低指数值（对应较低的植被生产水平），另一套针对高指数值。本栅格数据集可输出牧场植被的年度生产估算结果，有助于解析饲草资源的变化趋势与波动特征。用于生成Z分数的原始磅/英亩单位数据，以及该Z分数数据集，均可通过以下链接下载：https://data.fs.usda.gov/geodata/rastergateway/rangelands/index.php。