Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (9): 996-1005.DOI: 10.17521/cjpe.2021.0113

Special Issue: 青藏高原植物生态学:植物-土壤-微生物

• Research Articles • Previous Articles     Next Articles

Soil microbial biomass carbon, nitrogen, phosphorus and their stoichiometric characteristics in alpine wetlands in the Three Rivers Sources Region

NIE Xiu-Qing1,2, WANG Dong1,2,*(), ZHOU Guo-Ying3, XIONG Feng3, DU Yan-Gong3   

  1. 1Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Institute of Forest Ecology, Environment and Nature Conservation, Chinese Academy of Forestry, Beijing 100091, China
    2Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
    3Northwest Institute of Plateau Biology, Chinese Academy of Science, Xining 810008, China
  • Received:2021-03-26 Accepted:2021-07-03 Online:2021-09-20 Published:2021-08-26
  • Contact: WANG Dong
  • Supported by:
    National Key R&D Program of China(2018YFC0507305-2);National Natural Science Foundation of China(32001216);Second Tibetan Plateau Scientific Expedition and Research (STEP) Program(2019QZKK0302);National Key R&D Program of China(2019YFC0507404);Natural Science Foundation of Qinghai(2019-ZJ-910);Qinghai Province International Exchange and Cooperation Project(2019-HZ-807)

Abstract:

Aims Microbial biomass and their stoichiometric characteristics not only are important parameters of soil nutrient cycling, but also can contribute to prediction of climate changes, improvement of model accuracy, and understanding of terrestrial nutrient cycling. Our objective was to investigate microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) concentrations and their stoichiometric characteristics in alpine wetlands in the Three Rivers Sources Region.

Methods Using data from 50 sites, we explored MBC, MBN, MBP, their stoichiometry and their relationships with the controlling factors of alpine wetlands in the Three Rivers Source Region.

Important findings Our results showed that 1) MBC, MBN, MBP concentrations were 105.11, 3.79, 0.78 mmol·kg-1, respectively, and MBC:MBN, MBC:MBP, MBN:MBP, MBC:MBN:MBP were 50.56, 184.89, 5.42, 275:5:1, respectively. 2) Soil physical and chemical properties could significantly affect MBC, MBN and MBP concentration. Soil moisture had significantly negative effects on both MBC:MBN and MBC:MBP, while soil density had positive effects on both MBC:MBN and MBC:MBP. Soil total nitrogen content had negative relationship with MBC:MBP, while having weak effects on MBC:MBN. Soil physical and chemical properties also had weak effects on MBN:MBP. 3) Generally, soil microbial community composition had significant effects on MBC, MBN and MBP concentration. Soil microbial community composition had similar effects on MBC:MBN and MBC:MBP. Total phospholipid fatty acid (PLFA) content, gram-positive bacteria, gram-negative bacteria, bacteria, actinomycete, arbuscular mycorrhizal fungi concentration, and other PLFA content had negative effects on MBC:MBN and MBC:MBP, while fungi:bacteria had positive effects on both MBC:MBN and MBC:MBP, but fungi had weak relationships with both MBC:MBN and MBC:MBP. Except for arbuscular mycorrhizal fungi, MBN:MBP had weak relationships with soil microbial community composition. Soil physical and chemical properties, and soil microbial community composition had significant effects on soil microbial biomass and their stoichiometric characteristics in Three Rivers Sources Regions in the alpine wetlands, which are greatly helpful for deeply understanding of terrestrial high altitude nutrient cycling.

Key words: Qingzang Plateau, alpine wetlands, microbial biomass, stoichiometric characteristic, microbial community structure