Journal Article Soil 7440-44-0 Carbon 142M471B3J Alpine grasslands CO2 enrichment Carbon Dioxide N762921K75 Nitrogen Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. alpine grassland alpine meadow belowground carbon input biodiversity and stability canopy tree thinning climate warming community composition grassland biomass production grassland management herbivory microbial necromass carbon nitrogen (N) addition plant traits root trenching soil C-climate feedback soil respiration species diversity temperature sensitivity