Global aboveground biomass carbon density of crops in the year 2010

This layer represents the aboveground biomass (AGB) carbon (C) density estimates for crops that were used to create the harmonized global AGB C density map of Spawn et al. (2020). It has been scaled by 10 to reduce file size and should by multiplied by 0.1 before analysis to attain units of megagrams C per hectare (MgC/ha). Since crops may coexist with other vegetation types within the extent of a given grid cell, estimates in this layer have been proportionally adjusted to account for the relative spatial extent that crops are assumed to occupy in each grid cell. Grid cells that do not contain crops report a value of zero. As such, taking the pixelwise sum of the accompanying layers for tree, grass, tundra and crop AGB C will produce the harmonized global AGB C density map of Spawn et al. (2020).

本图层呈现了用于构建Spawn等人（2020）所提出的标准化全球地上生物量（aboveground biomass, AGB）碳（C）密度图的作物地上生物量碳密度估算值。为减小文件体积，本数据已按10倍比例缩放，分析前需将其乘以0.1，以得到每公顷兆克碳（MgC/ha）的单位。由于在给定网格单元范围内，作物可能与其他植被类型共存，本图层的估算值已按比例调整，以适配各网格单元中作物假设占据的相对空间占比。不含作物的网格单元数值为0。据此，将树木、草本、苔原与作物的地上生物量碳配套图层进行逐像素求和，即可得到Spawn等人（2020）所提出的标准化全球地上生物量碳密度图。