Apportioning above-and below-ground effects of moss biocrusts on soil detachment by overland flow in a subtropical climate  

作　　者：ZHANG Guan-hua YI Liang DING Wen-feng LEI Xu WANG Yi-ran SUN Bao-yang LI Jian-ming 

机构地区：[1]Soil and Water Conservation Department,Changjiang River Scientific Research Institute,Wuhan 430010,China [2]Research Center on Mountain Torrent&Geologic Disaster Prevention of Ministry of Water Resources,Wuhan 430010,China [3]Central-Southern Safety&Environment Technology Institute Co.,Ltd,Wuhan 430071,China

出　　处：《Journal of Mountain Science》2021年第10期2646-2655,共10页山地科学学报（英文）

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.41877082);the Fundamental Research Funds for Central Public Welfare Research Institutes(Grant No.CKSF2021487/TB,CKSF2021447/TB)。

摘　　要：Biocrusts affect soil detachment through above-ground(top crust’s surface covering)and below-ground(sub-crust’s binding and bonding,B&B)effects,which might vary with biocrust development or coverage.However,these effects in humid climates are still unclear.This study was conducted to apportion and quantify the surface covering and B&B effects of moss biocrusts with five coverage levels(1%–20%,20%–40%,40%–60%,60%–80%,and 80%–100%)on soil detachment by overland flow in a subtropical humid climate.Two treatments with one being intact moss crusts and one removing the aboveground moss tissues were designed for each coverage level,and bare soil was used as the baseline.The results indicated that soil detachment capacity(Dc)and rill erodibility(Kr)decreased with biocrust coverage.After removing the above-ground moss tissues,the impeding effect of biocrusts on soil detachment weakened,but still increasing soil erosion resistance relative to bare soil.For intact crust,Dc was reduced by 50%–95%compared with bare soil,wherein 36%–55%and 14%–40%were attributed to the surface covering and B&B,respectively.The top crust contributed more than sub-crust to the soil detachment reduction,which were related to but not linear with biocrust coverage.When biocrust coverage reached mid-to-higher level(40%–100%),both top crust and sub-crust steadily contributed to soil detachment reduction with 60%and 40%,respectively.The findings advance a better understanding of the influencing mechanism of biocrusts on soil erosion in humid climates and highlight the importance of saving biocrusts as ecosystem functions.

关 键 词：Soil detachment Rill erodibility Effect apportionment Contribution rate Three Gorges 

分 类 号：S157.1[农业科学—土壤学]