草原沙地微生物结皮与固沙作用的研究

Microbial Crust and Its Function on Sand -Fixing in Sandy land

采用野外调查采样、室内分析测定的方法,对内蒙古鄂尔多斯库布齐沙地(带)固定沙丘微生物结皮和流动沙丘表层进行了研究。结果表明,固定沙丘和流动沙丘的植被盖度分别为30%～50%和5%～10%;粒径0.05～0.01mm以下的沙粒分别占38.46%和1.94%;两者之间的微生物数量关系是:细菌24.53∶1;放线菌2.87∶1;真菌35∶1;固定沙丘微生物结皮与细沙粒所占比例、微生物各类群数量和微生物结皮的养分含量均呈正相关关系。

Through site sampling and investig ation,microbial crust in stabilize d sand dunes and surface layer of shifting sand dunes(0-5cm)were studied in the Hobq Desert of Inner Mongolia.The cover degrees of ve getation in stabilized sand dunes wi th mi-crobial crust and in surface layer of shifting sand dunes were 30-50%and 5-10%and the particles smaller than 0.05～0.01mm counted for 38.46%and 1.4%respectively.The microbe number differed i n the stabilized sand dunes and shift ing sand dunes,the bacteria number ratio was 24.53i n the former to 1.00in the latter,ant inomyces 2.87to 1.00and fungi 35.00to 1.00.The positive correlations were found between microbial crust and the proportion of fine sand particles,differe nt microbe number and the nutrient content in microbial crust.The facts stated above suggested th at the microbial crust played an important role in stabilizing the shifting sand dunes,protecting sta bilized sand dunes from the erosion a nd preventing soil against desertif ication and against sand -dust storm.