Plot-To-Map: an Open-Source R Workflow For Above-Ground Biomass Independent Validation

Maps of above-ground biomass (AGB) maps derived from Earth Observation (EO) have been increasing as a reflection of their importance in global and national applications such as global climate modelling and carbon accounting, respectively. Here we present Plot-To-Map, a tool to validate the accuracy of AGB maps using plot data from freely available global plot networks or own user data. The tool consists of five main steps starting from quality checking and harmonizing plot data to address the spatial (e.g., forest area) and temporal gaps between plots and maps. Uncertainties of plots are assessed before map comparison so plots with high uncertainty will have less impact on the comparisons. The comparison is initiated at a coarse spatial scale e.g., 10 km to eliminate random errors and enable systematic errors (bias) to be revealed and eventually be modelled. Bias predictions from decision tree-based regression model and other ecological EO products are key for producing bias-reduced maps and estimates of country AGB with associated uncertainties. The tool can be used locally and interactively via https://github.com/arnanaraza/PlotToMap. Its access and use are also possible through the Multi-Mission Algorithm Platform (MAAP), a joint project of ESA and NASA to revolutionize AGB research.