生物土壤结皮对荒漠区土壤微生物数量和活性的影响

发布时间：2019-05-29 23:23

【摘要】：生物土壤结皮对荒漠生态系统的维持与改良发挥着重要作用。土壤微生物可敏感地指示土壤质量,是衡量荒漠区生态健康程度的重要生物学特征,而对荒漠区生物土壤结皮与土壤微生物关系知之甚少。本研究设计了两组对比试验。一组以腾格里沙漠东南缘的1956、1964、1981、1991年的植被固沙区结皮下的沙丘土壤为对象,以流沙区和天然植被区为对照。另一组以植被固沙区人为干扰生物土壤结皮下的沙丘土壤为研究对象,以未干扰结皮下的沙丘土壤为对照。结果表明:腾格里沙漠东南缘植被固沙区的藻-地衣和藓类结皮均可显著提高土壤可培养微生物的数量和基础呼吸(P0.05);适度人为干扰生物土壤结皮不会显著影响土壤可培养微生物的数量和基础呼吸,而严重人为干扰结皮可显著降低土壤可培养微生物的数量和基础呼吸,指示严重人为干扰结皮可导致荒漠区土壤质量下降;土壤可培养微生物的数量和基础呼吸也因结皮演替阶段的不同而有所不同,演替晚期的藓类结皮下土壤微生物数量和基础呼吸显著高于演替早期的藻-地衣结皮(P0.05);土壤可培养微生物的数量和土壤基础呼吸与固沙年限均存在显著的正相关关系,随着沙丘固沙年限的增加,结皮层增厚,结皮下土壤微生物数量及基础呼吸显著增加(P0.05);生物土壤结皮下土壤可培养微生物数量和基础呼吸呈现显著的季节变化,表现为夏季秋季和春季冬季。因此,腾格里沙漠东南缘植被固沙区的生物土壤结皮提高了土壤微生物数量和活性,表明生物土壤结皮有利于荒漠区土壤及荒漠生态系统的恢复。
[Abstract]:Biological soil crust plays an important role in the maintenance and improvement of desert ecosystem. Soil microorganisms can sensitively indicate soil quality and are important biological characteristics to measure the degree of ecological health in desert areas, but little is known about the relationship between biological soil crusts and soil microorganisms in desert areas. In this study, two groups of comparative experiments were designed. In one group, the sand dune soil under the crust in the vegetation sand fixation area in 1956, 1964, 1981 and 1991 in the southeast edge of Tenggli Desert was taken as the object, and the flowing sand area and the natural vegetation area were taken as the control. In the other group, the sand dune soil under the crust of biological soil was artificially disturbed by vegetation sand fixation area, and the sand dune soil which did not interfere with the crust was taken as the control group. The results showed that algae lichen and moss crust in the sand fixation area of the southeast margin of Tenggli Desert could significantly increase the number of culturable microorganisms and basic respiration of soil (P 0.05). Moderate artificial disturbance of biological soil crust did not significantly affect the number and basic respiration of culturable microorganisms in soil, while serious human disturbance of crust could significantly reduce the number and basic respiration of culturable microorganisms in soil. It is indicated that serious human interference with crust can lead to the decline of soil quality in desert areas. The number and basic respiration of culturable microorganisms in soil varied with the stage of crust succession. The number of soil microorganisms and basic respiration in the late stage of succession were significantly higher than those in the early stage of succession (P 0.05). There was a significant positive correlation between the number of culturable microorganisms and the number of soil basic respiration and the number of sand fixation years. With the increase of sand fixation years in sand dunes, the crust thickened. The number of soil microorganisms and basic respiration increased significantly (P 0.05). The number of culturable microorganisms and basic respiration in biological soil under crust showed significant seasonal variation, which was summer, autumn and spring and winter. Therefore, the biological soil crust in the sand fixation area of vegetation in the southeast margin of Tenggli Desert increased the number and activity of soil microorganisms, which indicated that biological soil crust was beneficial to the restoration of soil and desert ecosystem in desert area.
【作者单位】：甘肃农业大学草业学院;甘肃林业职业技术学院;天水师范学院生物工程与技术学院甘肃省高校农业微生物重点实验室;中国科学院西北生态环境资源研究院沙坡头沙漠试验研究站;
【基金】：国家自然科学基金项目(41761057) 甘肃省自然科学基金项目(1610RJZE133)
【分类号】：S154.3

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