Community-level root trait, environmental data and R codes.xlsx

To uncover the pattern of root trait space at the community-level and their driving factors, we selected two typical grasslands in China, i.e., the Inner Mongolian Plateau (IMP) and the Tibetan Plateau (TP), where plant growth is predominantly limited by water and low temperature, respectively. Ten sampling sites from east to west in each region were set up and nine community-level root quantity and efficiency traits were determined. The root traits were calculated using three alternative upscaling approaches, and were grouped into two datasets, including four root quantity traits and five root foraging and uptake efficiency traits estimated from the pooled-species approach or CWM approach, respectively. Specifically, root quantity traits include total root mass (RM_A), root length (RL_A), root area (RA_A), and root nitrogen content per unit land area (RN_A). Root efficiency traits include the pooled-species values of mean root diameter (RD_M), specific root length (SRL_M), specific root area (SRA_M), root tissue density (RTD_M), root nitrogen concentration (RN_M); and CWM values of root diameter (RD_CWM), specific root length (SRL_CWM), specific root area (SRA_CWM)), root tissue density (RTD_CWM), root nitrogen concentration (RN_CWM). Climatic and soil variables (0–30 cm depth) were used to determine the environmental effects on variation in community-level root traits.