County-scale biomass map comparison: a case study for Sonoma, California

ABSTRACTThe amount of carbon stored in forests affects a wide range of regional- to global-scale climate change processes. However, current maps often show large differences in carbon accounting. In this study, we present a framework to evaluate and compare multiple recent biomassmaps at the county scale (4119 km2). We first compare the differences in the forest and non-forest areas at the pixel and county levels from multiple maps. Map-based estimates of county-level mean and total biomassare compared to the United States ForestService (USFS) sample-based estimates. Comparison of raster-based biomassproducts shows differences in mean and total biomassat both pixel- and county-levels. Despite all the maps using USFS's plot data for model training, only the three active sensor derived products compare well to USFS's estimates of total biomass(within 10%), while the three passive sensor derived map products underestimated total biomassby as much as 47%. Our evaluation demonstrates that the biomassma...