A High-Resolution Gridded Dataset of Vertically Resolved Fine Root Biomass From 2005 to 2025 Across China

Model evaluation demonstrates the developed models explains approximately 86% and 81% variations in surface FRB densities across woody and herbaceous ecosystems, respectively. Woody plants exhibit deeper root distributions in arid regions, whereas herbaceous species show consistently surface-concentrated rooting patterns across climate zones. The controlling factors of surface FRB density also differ between vegetation types: woody FRB density is primarily influenced by root traits and nutrient availability, while herbaceous FRB is more strongly regulated by climatic conditions.

In contrast, the vertical distribution of woody FRB is mainly governed by species richness and aridity, whereas that of herbaceous FRB is controlled by soil texture, elevation, and temperature. In addition, environmental change over the past two decades has notably altered both the total amount and the vertical distribution patterns of FRB across China. The dataset developed in this study provides a new observationally constrained benchmark for understanding belowground carbon dynamics.</p>