欢迎访问《生态学杂志》官方网站,今天是 分享到:

生态学杂志

• 研究报告 • 上一篇    下一篇

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

李茜倩1,2,张元明1*   

  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

摘要: 藓类结皮是荒漠地表生物土壤结皮的主要类型之一,能影响荒漠地表稳定、土壤水分与养分以及种子植物生长等。自然状态下,藓类结皮通常呈现出典型的斑块状分布特征。本研究以新疆北部古尔班通古特沙漠藓类结皮为对象,在斑块尺度上,将藓类结皮斑块从中心至边缘划分3个圈层,分析了藓类结皮斑块中心到边缘不同圈层土壤理化性质、酶活性及微生物生物量的变化特征。结果表明:土壤有机质、全氮、全钾显著受边缘效应影响,中心圈层含量显著高于边缘圈层,其他土壤指标在3个圈层无显著差异;边缘圈层处脲酶和过氧化氢酶活性显著低于内部2个圈层,而蔗糖酶及碱性磷酸酶活性在3个圈层均无显著差异;微生物生物量碳(SMBC)、微生物生物量氮(SMBN)从中心向边缘圈层均呈降低的趋势,且边缘圈层显著低于内部2个圈层;同时,各土壤理化性质、酶活性和微生物生物量在斑块内部2个圈层均无显著差异;通径分析表明,影响脲酶活性的直接因素和主要因素均为有机质;过氧化氢酶活性与SMBC更易受边缘效应的影响,各因素中距离对二者的直接通径系数最高,分别达到-1.108及-1.224;有机质、pH值、速效K以及全K对SMBN直接通径系数均较大,但各因素通过有机质对SMBN的间接通径系数也较大,SMBN受土壤理化性质及距离多个因素的直接及间接影响;此外,过氧化氢酶活性及SMBC的剩余项的通径系数均较大,表明受其他未被考虑因素的较大影响。

关键词: 空间关联, 空间分布, 檵木, 岩溶石山, Ripley K函数

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.

Key words: karst hill, Loropetalum chinense, spatial association, Ripley K(r) function, spatial distribution