不同利用方式下草地土壤微生物及土壤呼吸特性

摘要

通过对呼伦贝尔羊草(Leymus chinensis)草甸草原土壤呼吸特性及土壤微生物的测定,研究了3种不同利用方式(围封、放牧和刈割)对天然草地土壤呼吸特性及土壤微生物的影响,为草甸草原土壤呼吸研究提供基础理论依据.结果表明:不同利用方式下土壤呼吸速率、土壤微生物量碳含量与土壤酶活性(除脲酶)均表现为草地围封比放牧和刈割呼吸速率高(含量高、活性强)；土壤微生物量氮含量、脲酶活性和微生物数量表现为草地放牧和刈割比围封的含量高(活性强、数量多)；土壤微生物量碳、氮含量、土壤酶活性(除脲酶)和土壤微生物数量均以表层(0～10 cm)最高(活性最强、数量最多),随着土层深度增加而降低(活性下降、数量减少).土壤呼吸速率与微生物量碳、土壤酶活性(除过氧化氢酶)成正相关,与微生物量氮、过氧化氢酶和微生物数量成负相关,其中只与微生物量氮相关性显著,而其余之间均不显著.%Effects of three different use patterns of grassland (exclosure,grazing,mowing)on soil respiration and soil microorganism were studied at the Leymus chinensis meadow steppe of Hulunber in this paper. Results were that soil respiration rate, soil microbial biomass carbon and soil enzyme activities (except ure-ase)in enclosed grassland were higher (both contents and activities) than that in grazing and mowing grassland under different use patterns. Soil microbial biomass nitrogen, urease activity and microbial biomass were higher (both activity and quantity) under grazing and mowing patterns than under enclosed pattern. The contents of microbial biomass carbon, soil enzyme activities (except urease) and soil microbial biomass were highest in surface soil (0~10 cm) then decreased (both activity and number) in deeper soil depths. Soil respiration rate had a positive correlation with soil microbial biomass carbon and soil enzyme activity (except catalase), but a negative correlation with the soil microbial biomass nitrogen, catalase and the soil microorganism quantities.