Global belowground biomass carbon density of crops in the year 2010 – uncertainty

This layer represents the uncertainty of the belowground biomass (BGB) carbon (C) density estimates for crops that were used to create the harmonized global BGB 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 root sum of the squared accompanying layers for tree, grass, tundra and crop BGB C will produce the uncertainty layer of the harmonized global BGB C density map of Spawn et al. (2020).