科尔沁沙地植物萌动期不同类型沙丘土壤微生物区系特征

Characteristics of Microbe Flora in Different Dunes During Plant Germination Period in Horqin Sandland

通过对科尔沁沙地植物萌动期不同类型沙丘中0-50cm土壤层微生物组成及其与生态因子的关系研究表明:微生物的活动强弱程度是:固定沙丘>半固定沙丘>半流动沙丘>流动沙丘,每种沙丘类型中不同微生物类群数量分别是:细菌>放线菌>真菌。微生物数量在垂直分布上表现为:流动沙丘表层最少,30—40cm层活动相对强烈;半流动沙丘和半固定沙丘在垂直分布上变化相对较小;固定沙丘表层最多,表层以下变化不大。各类群微生物数量与电导率、植被盖度、凋落物量和沙丘固定程度都呈显著正相关(P≤0.01);pH值对放线菌的影响最大,其次为细菌,而对真菌的影响较小。微生物活动与地温的相关性不高,与土壤水分含量呈负相关。影响科尔沁沙地土壤微生物的主要生态因子是植被盖度和土壤可溶性无机盐含量。

The research is about the characteristics of microbe flora in 0-50 cm soil layers and their relationship with ecological factors in different dunes during plant germination period in Horqin Sandland. The results show that the microbe activity in fixed dune〉that in semi-fixed dune〉that in semi-mobile dune 〉 that in mobile dune; the amount of microbe in any dunes is that the amount of bacteria〉the amount of actinomyces〉the amount of fungi. The vertical distribution of microbe numbers shows： the least in the upper layer and the most at the 30-40 cm layer in the mobile dune; relatively less variant in every soil layer in both the semi-mobile dune and the semi-fixed dune; the most in the surface layer and less variant in below surface layers in the fixed dune. The microbe number has positive relationship with electronic conductance, with plant coverage density, with litter content and with dune stabilized degree （P≤0.01）. The soil pH value has the most influence on actinomyces, the second on bacteria, and the least on fungi. The ground temperature has little effect on soil microbe activity in early May, whereas soil moisture has an obviously negative relationship with the activity of microbe. The main ecological factors that play important role on soil microbe activity include plant coverage density and soluble inorganic salinity during the plant germination period in Horqin Sandland.