三江平原小叶章湿地土壤微生物活性特征研究

Microbial activity in soils of Calamagrostis angustifolia wetlands in the Sanjiang Plain

选取三江平原河滨湿地、沼泽湿地和草甸化湿地3种类型小叶章湿地0-20cm土壤,研究了不同类型湿地土壤总有机碳（TOC）、微生物生物量碳（MBC）、微生物生物量氮（MBN）、基础呼吸（BR）、呼吸势（PR）、微生物熵（Cmic/Corg）和代谢熵（qCO2）变化规律.结果表明,不同类型小叶章湿地土壤总有机碳、微生物生物量碳和基础呼吸分别为46.60-75.44g·kg^-1、1106.86-2319.42mg·kg^-1和5.72-10.10mg·kg^-1·h^-1.河滨湿地和沼泽湿地土壤总有机碳、微生物生物量碳、微生物生物量氮、基础呼吸、呼吸势和微生物熵均显著高于草甸化湿地（p〈0.01）,而河滨湿地和沼泽湿地代谢熵明显低于草甸化湿地（p〈0.05）.各土壤微生物活性指标在河滨湿地和沼泽湿地间均无明显差异.因而,相对于河滨湿地和沼泽湿地,草甸化湿地土壤微生物活性处于较低水平,土壤总有机碳和水分含量低是限制草甸化湿地土壤微生物活性的重要因素.

To explore the microbial activity in soils of Calamagrostis angustifolia wetlands in the Sanjiang Plain,the top 0~20 cm soils of riparian,marsh,and meadow wetlands were selected.Total organic carbon（TOC）,microbial biomass carbon（MBC）,microbial biomass nitrogen（MBN）,basal respiration（BR）,potential respiration（PR）,microbial quotient（Cmic/Corg）,and metabolic quotient（qCO2）of soils of the three wetland types were investigated.The results showed that TOC,MBC and BR of soils of the three wetland types ranged over 46.60~75.44 g·kg-1,1106.86~2319.42 mg·kg-1 and 5.72~10.10 mg·kg-1·h-1,respectively.The TOC,MBC,MBN,BR,PR and Cmic/Corg of riparian and marsh soils were higher than those of meadow wetland and significant differences were found at p0.01.The soil metabolic quotient of riparian and marsh was lower than that of meadow wetland and differed significantly at p0.05.No differences were found between TOC,MBC,MBN,BR,PR,Cmic/Corg and qCO2 of riparian and marsh soil.Thus,the soil microbial activities of meadow wetland are low in comparison with those of riparian and marsh,and the microbial activities of meadow wetland are confined to the TOC and water content.