北方农牧交错带沙地生物结皮研究

The Study on Ecological Meaning of the Microbiotic Soil Crust in Agriculture Animal Husbandry of the Northwest China

为了解我国北方农牧交错带生物结皮的生态意义,本文以宁夏盐池为例,采用样线调查法进行结皮及植被调查,并在有结皮和无结皮覆盖两种情况下进行入渗试验。研究表明:北方半干旱区生物结皮对植物生长存在先促进、后抑制的过程。在风蚀环境条件和不稳定的土壤条件下,生物结皮的出现可创造适合植物生长的微环境,为植物的生长提供了条件。方差分析显示有结皮时的植被盖度明显高于无结皮覆盖的植被盖度。当环境条件改善时,结皮开始抑制植物的生长,两者存在一种显著的线性负相关关系。研究区从封育边缘到核心,结皮盖度为核心>边缘,植被盖度正好相反,两者的相关系数高达-0.920;生物结皮对入渗具有明显的阻碍作用,结皮盖度与入渗深度之间呈线性负相关,相关系数为-0.765,说明结皮的存在使土壤水分呈现浅层化趋势。

In order to understand the ecological meaning of the microbiotic soil crust in agriculture and animal husbandry of the North interlocks and takes, this research took Yanchi of Ningxia as an example to carry on the survey of soil crust and vegetation, and go on the test of infiltration with crust and no curst. The results showed, the microbiotic soil crust inhibited the growth of the plant after promoting it in Northern semi - arid region. The microbiotic soil crust could create the microenvironment that was suitable for plant growth on the abominable environmental condition and unstable soil. Variance analysis revealed that the vegetation covery with crust covers was obviously higher than that not having it. As the environment improved, the crust covers began to inhibit the growth of plant. From the edge to the core in the study area, the covering degree of crust cover was shown as core 〉 edge, but the vegetation covery was opposite. The coefficient correlation of the two was more than 0. 920 ; the microbiotic soil crust had the obvious hindrance function in rain infiltration. It was showed that the existence of crust made soil moisture appeared shallow.