论文部分内容阅读
为探明生物土壤结皮在半干旱沙地生态系统有限降水资源再分配过程中所扮演的重要角色,对毛乌素沙地南缘沙丘生物土壤结皮表面径流进行了实验观测.结果表明在观测期间的6次降雨事件中产生径流2次.不同类型生物土壤结皮的径流量差异较大,径流量由小到大依次为浅色藻类结皮、深色藻类结皮、苔藓结皮,显示径流量随生物土壤结皮的发育呈增加的趋势.径流在次降雨量中所占的百分比由浅色藻类结皮经深色藻类结皮至苔藓结皮依次增加,显示不同类型生物土壤结皮对降水的再分配比例有差异.生物土壤结皮表面径流受降雨量、降雨强度、雨前结皮表面的水分饱和程度及生物土壤结皮发育程度的共同影响.生物土壤结皮在沙丘表面的发育改变了半干旱沙地生态系统水分的空间分布,加大了水分和养分等资源的异质性.因此,暴雨季节对生物土壤结皮进行适当的人为干扰活动有益于半干旱沙地生态系统的资源均衡.
In order to find out the important role of biological soil crusts in the redistribution of limited precipitation resources in semi-arid sandy ecosystems, the surface runoff of biological soil crusts in the dunes in the southern margin of the Mu Us desert was observed experimentally.The results show that during the observation period Of the six rainfall events runoff 2. Different types of biological soil crust runoff large differences in order of runoff from light to coarse algae crusts, dark algal crusts, moss crust, showing runoff With the development of biological soil crusts showed an increasing trend.The percentage of runoff in the secondary rainfall from the dark-colored algae skin crusts to the moss crust increased in turn, indicating that different types of biological soil crust precipitation Redistribution ratio of biological soil crusts.The surface runoff of biological soil crusts was affected by rainfall, rainfall intensity, the degree of water saturation on the skin surface before rain and the degree of development of biological soil crusts.The development of biological soil crusts on the dune surface changed The spatial distribution of water in semi-arid sandy ecosystems increases the heterogeneity of resources such as water and nutrients, therefore, the biological soil crust Anthropogenic interference with the activities of beneficial resource leveling semi-arid sandy grassland ecosystem.