• 研究报告 •

荒漠藓类结皮斑块中土壤理化性质、酶活性及微生物生物量分布的边缘效应

1. (1中国科学院新疆生态与地理研究所， 中国科学院干旱区生物地理与生物资源重点实验室， 乌鲁木齐 830011；2中国科学院大学， 北京 100049)
• 出版日期:2018-07-10 发布日期:2018-07-10

The horizontal distribution of soil physicochemical properties, soil enzyme activities, and microbial biomass in moss crust patch in a temperate desert.

LI Xi-qian1,2, ZHANG Yuan-ming

1. (1Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; 2University of Chinese Academy of Sciences, Beijing 100049, China).
• Online:2018-07-10 Published:2018-07-10

Abstract: Moss crust, one of the main types of biological soil crust in deserts, influences sand surface stability, soil water and nutrition distribution, and the growth of vascular plants. In natural conditions, moss crusts mainly occur in patches with different sizes. However, the horizontal distribution pattern and edge effect of the patches remain unclear. In this study, three circles with different distances (r=3.5, 7, and 10 cm, respectively) from the center to the edge of the moss crust patch (about r=10 cm) were settled, and soil physicochemical properties, enzyme activities, and microbial biomass were analyzed. The results showed that: (1) Soil organic matter, total nitrogen and total potassium concentrations were significantly influenced by the edge effect, being higher in the inner and middle circles and lower in the outer circle. There was no significant difference of other soil indicators in the three circles. (2) The activities of urease and catalase in the outer circle were significantly lower than that in the middle and inner circles, while the activities of sucrase and alkaline phosphatase had no significant difference among the three circles. Soil microbial biomass carbon (SMBC) and nitrogen (SMBN) significantly decreased from inner to outer circle, while there was no significant difference between the inner and middle circles. (3) Results from the path analysis showed that soil organic matter concentration was the direct and main factor influencing urease activity. Catalase activity and SMBC were more sensitive to the edge effect, with the direct path coefficient of distance to these two variables being higher than other direct path coefficients (-1.108 and -1.224, respectively). The soil organic matter concentration, pH, and available and total K concentrations had high direct path coefficients for SMBN, with high indirect path coefficients for SMBN via organic matter concentration. Therefore, SMBN was affected by multiple physical and chemical factors and distance. In addition, the residual path coefficients of catalase activity and SMBC were relatively high, implying that other factors being not considered had strong influence on the two variables.