Soil available nitrogen, dissolved organic carbon and microbial biomass content along altitudinal gradient of the eastern slope of Gongga Mountain

摘要: Abstract Gongga Mountain is a unique mountain in western China which has not only modern low-latitude glaciers, but also an integrated vertical vegetation distribution from subtropical forests to tundra. Our study aimed understand the soil fertility status of subalpine and alpine ecosystems this region through measuring available nitrogen (SAN), dissolved organic carbon (DOC) microbial biomass (SMB) along eastern slope Mountain. We found that SAN, DOC SMB varied altitudinal gradient, decreased surface subsurface, probably due different return plant residue, decomposition rate, as well temperature moisture elevations. The range NH 4 + −N content was 1.7 mg kg−1 134.2 mg kg−1; NO 3 -  +  2 2.6 mg kg−1 202.0 mg kg−1; 30.6 mg kg−1 610.2 mg kg−1; (SMBC) 41.4 mg kg−1 2538.5 mg kg−1; (SMBN) 0.6 mg kg−1 410.7 mg kg−1. were all significantly related each other, indicating these three indexes are dependent on matter. At last, ratio SMBC SMBN ranged 2.4 65.3, mostly less than 6.0, meant bacteria dominated community our sites.