甘南草地土壤微生物与理化特性

在甘肃省甘南州境内，土壤微生物呼吸强度在不同草地类型草地上由大到小的顺序：0~15 cm深度为沼泽化草甸>高寒灌丛草甸>高寒草甸>亚高寒草甸>山地草原，15~30 cm深度为沼泽化草甸>亚高寒草甸>山地草原>高寒灌丛草甸>高寒草甸，30~60 cm深度为沼泽化草甸>山地草原>亚高寒草甸>高寒草甸>高寒灌丛草甸；微生物碳在不同草地类型草地上由大到小的顺序：0~15 cm与15~30 cm深度均为沼泽化草甸>高寒灌丛草甸>高寒草甸>亚高寒草甸>山地草原，30~60 cm深度为沼泽化草甸>亚高寒草甸>高寒灌丛草甸>高寒草甸>山地草原。同一草地类型的土壤呼吸强度、微生物碳都在各自土壤深度下随深度增加而减小，代谢熵的变化趋势刚好相反，微生物商的变化趋势不明显。土壤呼吸强度、微生物碳均分别与土壤含水量、有机碳、全氮呈极显著正相关（P<0.01），而代谢熵与之呈极显著负相关（P<0.01），微生物商与含水量、全氮呈极显著正相关（P<0.01），而与有机碳呈极显著负相关（P<0.01）。

Soil properties associated with microbe in different types of Gannan grassland

In Gannan region of Gansu province, the numerical sizes of respiration rates of different grassland type soils are: swamping meadow>alpine shrub meadow>alpine meadow>sub alpine meadow>upland meadow (0-15 cm), swamping meadow>sub alpine meadow>upland meadow>alpine shrub meadow>alpine meadow (15-30 cm), and swamping meadow>upland meadow>sub alpine meadow>alpine meadow>alpine shrub meadow (30-60 cm). The numerical sizes of soil microbial biomass carbon of different grassland type soils are: swamping meadow>alpine shrub meadow>alpine meadow>sub alpine meadow>upland meadow (0-15, 15-30 cm), and swamping meadow>sub alpine meadow>alpine shrub meadow>alpine meadow>upland meadow (30-60 cm). Respiration and microbial biomass carbon of different grassland type soils decreased with soil depth, while respiratory quotient increased and microbial quotient has no significant change. There was a significant positive correlation (P<0.01) between respiration, microbial biomass carbon and soil moisture, total organic carbon, total nitrogen, and a significant negative correlation (P<0.01) between respiratory quotient and soil moisture, total organic carbon, total nitrogen. A significant positive correlation (P<0.01) exists between microbial quotient and soil moisture, total nitrogen, while a significant negative correlation (P<0.01) exists between microbial quotient and total organic carbon.