黄土丘陵区草本植物覆盖下生物结皮对坡面径流流速的削减作用  

Reduction of flow velocity by biological soil crust of revegetated grassland in the hilly Loess Plateau,China

作　　者：郭雅丽 赵允格 高丽倩 杨凯[1,2] 孙会 谷康民 GUO Ya-li;ZHAO Yun-ge;GAO Li-qian;YANG Kai;SUN Hui;GU Kang-min(College of Resources and Environment,Northwest A&F University,Yangling 712100,Shaanxi China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shaanxi,China;College of Forestry,Northwest A&F University,Yangling 712100,Shaanxi China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]西北农林科技大学林学院,陕西杨凌712100

出　　处：《应用生态学报》2022年第7期1871-1877,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41830758,41907056,41571268);中国科学院“西部之光”交叉团队项目-重点实验室合作研究专项(2019)资助。

摘　　要：生物结皮是干旱半干旱地区的常见地被物,与植物共同影响坡面径流及流速。迄今鲜有研究关注植物和生物结皮共同覆盖对流速的影响,是干旱半干旱地区坡面侵蚀驱动因素研究的薄弱环节。本研究以黄土丘陵区退耕草地为对象,通过野外模拟降雨试验,研究草本植物覆盖下有无生物结皮及不同组成生物结皮(多藻少藓、多藓少藻和藓)对径流流速的影响。结果表明:植物和植物+生物结皮覆盖显著降低了流速,植物覆盖较裸土降低70.7%,植物+生物结皮覆盖较裸土降低83.1%;植物和生物结皮共同覆盖下,植物和生物结皮对径流流速的削减效益分别为70.7%和12.4%。植物覆盖下生物结皮对流速的影响程度与其组成有关,多藻少藓结皮、多藓少藻结皮和藓结皮对流速的削减效益分别为11.5%、12.4%和19.4%。流速与藓盖度呈显著负相关,与藻盖度呈显著正相关,藓结皮盖度(x)与流速(y)的关系式为:y=-2.081x+0.03(R^(2)=0.469)。当植物盖度一定时(40%±10%),生物结皮组成中藓盖度是影响共同覆盖坡面流速的关键因子。综上,草本植物覆盖下生物结皮有显著减缓流速的作用,且作用程度与其组成有关。表明在研究退耕草地坡面侵蚀动力机制时,生物结皮的作用应予以考虑。Biological soil crusts(biocrusts)are the common cover in arid and semiarid areas.Together with plants,biocrusts affect runoff and flow velocity.However,few studies have focused on the effects of the co-covering of plant and biocrust(plant+biocrust)on the flow velocity,with a knowledge gap in the study of driving factors for slope erosion in arid and semiarid areas.In this study,simulated rainfall experiments were used to investigate the effects of biocrust and three types of biocrusts(more cyanobacteria less moss,more moss less cyanobacteria,and moss)on the flow velocity of revegetated grassland in the hilly Loess Plateau.The results showed that plant and plant+biocrust significantly reduced flow velocity,with that of plants and plant+biocrust being 70.7%and 83.1%lower than bare soil.The reduction benefits of plant and biocrust on flow velocity were 70.7%and 12.4%,respectively,when they were co-covered.Biocrust composition under plant cover affected flow velocity.The reduction benefits of more cyanobacteria less moss,more moss less cyanobacteria,and moss crust on flow velocity were 11.5%,12.4%,and 19.4%,respectively.There was a significant negative correlation between flow velocity and moss coverage and a significant positive correlation between flow velocity and cyanobacteria coverage.The relationship between moss cove-rage(x)and flow velocity(y)was y=-2.081x+0.03(R^(2)=0.469).The moss coverage was a key factor affecting the flow velocity of co-covering of plant and biocrust slope with similar plant coverage(40%±10%).In conclusion,biocrusts under plant cover significantly slowed flow velocity,and the effect magnitude was related to its composition,implying that the role of biocrusts should be considered in understanding the mechanism underlying slope erosion in revegetated grassland.

关 键 词：生物结皮组成 退耕草地 径流流速 流速削减效益 

分 类 号：S157.1[农业科学—土壤学]