Journal Article Soil 7440-44-0 Carbon Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. N762921K75 Nitrogen grasslands 142M471B3J Carbon Dioxide Comment K50XQU1029 Nitrous Oxide SPRUCE experiment aboveground net primary production aboveground net primary production (ANPP) aboveground net primary productivity acclimation across-model spread altered precipitation anthropogenic perturbation belowground net primary production (BNPP) belowground net primary productivity big data assimilation biomass allocation biotic competition biotic responses carbon modeling carbon residence time