模块沙障对土壤微生物和酶活性变化的影响

Influence of Module Sand Barrier on Soil Microorganisms and Enzyme Activity

按照生态系统组成特征，在流动沙地人工构建了集防风固沙、局部土壤改良和植被恢复3大功能于一体的模块沙障。为掌握模块沙障对局部土壤生物特性的影响程度，测定了土微生物含量和土壤酶活-性，研究设置了5年后的模块沙障内部及其对周边土壤微生物数量和土壤酶活性变化的影响。结果表明，模块沙障内部土壤3大微生物总量比对照样地0～10cm土层高1．91倍，细菌、真菌和放线菌含量分别比对照样地高1．33倍、1_76倍和2．83倍。蔗糖酶和脲酶活性分别比对照样地增加2．47倍和67．64％；模块沙障覆盖下0—10cm土层土壤微生物总量比对照样地0—10cm土层高1．22倍，细菌、真菌和放线菌含量分别增加O．83倍、0．87倍和2．14倍，蔗糖酶和脲酶的活性分别比对照样地增加2．01倍和29．41％。此外。模块沙障及其内部填充基质能够通过降雨淋溶、填充基质扩散等作用有效的改善沙障迎风侧或背风侧70cm范围内土壤微生物含量和蔗糖酶、脲酶活性，实现了“肥岛作用“改善土壤的生物化学特征。

According to the composition characteristics of the ecosystem, a module sand barrier has been artificially constructed on moving sandy dune, which integrates sand fixation, partial soil improvement and vegetation restoration. To understand the influence of the module sand barrier on the biological characteristics of soil, soil microorganism amount and enzyme activity have been measured, and the variation of them inside and around the module sand barrier has been studied after construction for five years. The results show that inside the module sand barrier, the total amount of soil microorganisms was 1.91 times that of the one at 0-10 cm layer in the control plot, the amount of bacteria, fungi and aetinomycetes were 0.83 times, 0.87 times and 2.14 times higher than those in the control plot, and the sucrase and urease activities were increased by 2.01 times and 29.41% than those in the control plot. Moreover, the artificially constructed module sand barrier and its internal filling matrix can improve the soil microorganism amount, sucrase and urease activities during 0 to 70 cm of the windward side or leeward side of the module sand barrier, and the formed fertility island effect can improve the biochemical characteristics of the soil.