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为了解接种蓝藻对荒漠地区表土持水特性的改善作用,对库布齐沙漠东缘达拉特旗地区人工接种蓝藻后形成的生物结皮进行了发育演替及持水特性研究.结果表明,在人工接种荒漠蓝藻之后,藻结皮能够很快形成,并在一些微环境下藻结皮直接演替为藓结皮(接种2~3 a后).随着结皮的发育演替,表土生物量、多糖含量、厚度以及孔隙度增加,而土壤容重减小;同时,形成结皮之后表土质地也发生了明显的变化,其中沙粒含量逐渐减少,粉粒、黏粒含量增加.实验还发现随着结皮的发育演替,表土含水量与饱和持水量都呈增加的趋势,即:藓结皮>藻结皮>流沙,藻结皮中的含水量(饱和持水量)为流沙中的1.1~1.3倍,藓结皮中的含水量(饱和持水量)为流沙中的1.8~2.2倍.相关分析表明表土含水量及饱和持水量与表土生物量、多糖含量、厚度、容重、粉粒和黏粒含量呈正相关,与表土孔隙度和沙粒含量呈负相关.通过逐步回归分析发现影响含水量的主要因素为表土黏粒的含量,而影响饱和持水量的主要因素为表土孔隙度.
In order to understand the role of cyanobacteria in improving the water-holding capacity of surface soil in desert areas, the developmental succession and water-holding characteristics of the biological crusts formed after artificial inoculation with cyanobacteria in Dalate Banner on the eastern edge of the Kubuqi Desert were studied. After artificial inoculation of desert cyanobacteria, the algal crusts could form rapidly, and in some micro-environments, the algal crusts directly succeeded to moss crusts (after 2-3 days of inoculation) .With the development of crusts, topsoil The content of biomass, polysaccharide, thickness and porosity increased while the bulk density of soil decreased. At the same time, the topsoil texture also changed significantly after crust formation, in which the content of sand grains decreased and the content of silt and clay increased It was found that with the development of the crust, the water content and saturated water content of topsoil tended to increase, ie moss crust> algal crust> quicksand, the water content (saturated water content) in algal crust was 1.1 ~ 1.3 times higher than that of the control group.The water content in the moss crust (saturated water holding capacity) was 1.8 ~ 2.2 times that in quicksand.Correlation analysis showed that the topsoil water content, saturated water content and topsoil biomass, polysaccharide content, thickness, bulk density, Grain and clay content was positively correlated with surface porosity And sand content was negatively correlated. By stepwise regression analysis showed that the main factors affecting the moisture content of topsoil clay content, and the saturation of water is the main factor holding topsoil porosity.