Peer Review #2 of "Dynamics of nitrogen and active nitrogen components across seasons under varying stand densities in a Larix principis-rupprechtii (Pinaceae) plantation (v0.1)"

Changes in the concentration of soil N or its components may directly affect ecosystem functioning in forestry.Thinning of forest stands, a widely used forestry management practice, may transform soil nutrients directly by altering the soil environment, or indirectly by changing above-or belowground plant biomass.The study objectives were to determine how tree stem density affects the soil N pool and what mechanisms drive any potential changes.In this study, N and its active components were measured in the soil of a Larix principis-rupprechtiiplantation across two full growing seasons, in twelve 25*25m plots: LT (low thinning, removal of 15% of the trees, three plot repetitions), MT (35% removal) and HT (50% removal) and CK (no thinning control).Environmental indices, like the light condition, soil reoperation, soil temperatures and prescription, were measured in the plots also.Results indicated that STN (soil total nitrogen) was affected by tree stem density adjustments in the short-term; STN generally increased with decreasing tree stem density, reaching its highest concentration in the MT treatment before decreasing in HT.This pattern was echoed by the DON/STN ratio (DON, dissolve organic nitrogen) under MT.A lower DON/STN was measured across the seasons.MBN (microbial biomass nitrogen) and the SOC/STN (SOC, soil organic carbon) ratio and density treatments influenced MBN concentration and inhibited SOC/STN.MT tended to accumulate more STN, produce lower DON/STN and had a generally higher microbial activity, which may be partly ascribed to the higher MBN value, MBN/STN ratio and lower DON/STN.The water conditions (soil moisture), light and soil temperatures may partly be responsible for the N pool dynamic in the different density treatments.