Similarities and Differences of Development and Ecological Functions of Biological Soil Crusts between Loessland and Sandy Land
Biological soil crusts play an important role in arid and semiarid ecosystems.Based on the available research achievements of our team,the experimental areas with the similar climatic conditions and different soil textures in the wind-water erosion region on the Loess Plateau were selected to study the similarities and differences of development and ecological functions of biological soil crusts between loessland and Mu Us sandy land.The results are as follows:① The main biological soil crust species in both loessland land and sandy land were moss crusts.The species composition of moss crusts were Bryum argenteum Hedw.,B.caepititicium Hedw.and B.algovicum Sendt.in loessland,but the B.pallescens,B.recurvulum and B.argenteum in sandy land.The highest coverage of biological soil crusts under arbor-shrub vegetation was 77.5％ in sandy land,and the lowest one under perennial herbs was 50.5％ in loessland.In sandy land the thickest biological soil crust under annual herbs was 11.8 mm,and the thinnest one under perennial herbs was 9.5 mm;the highest shear strength of biological soil crusts under perennial herbs in loessland was 26.5 kPa,and the lowest one under perennial herbs in sandy land was 3.5 kPa;the highest density of biological soil crusts under annual herbs in sandy land was 1.9 g · cm-3,and the lowest one under perennial herbs in loessland was 1.1 g · cm-3;② When the values of precipitation in loessland and sandy land were 8.0 mm and 40.5 mm respectively,the soil infiltration rate in loessland was significantly higher than that in sandy land,but for the total infiltration (sum of increased soil moisture),there was no significant difference between loessland and sandy land;③ The average increase of soil moisture content at 0-200 cm soil profile in loessland was 1.4％ and 1.9％ higher than that in sandy land;④ Whether there were herbs or not,biological soil crusts had positive effects on soil loss reduction in both loessland and sandy land,and the highest contribution of biological soil crusts to soil loss reduction in sandy land was 90.6％,and the lowest one in loessland was only 0.3％.
loesslandsandy landbiological soil crustsoil moisture contentsoil erosionefficiency of soil loss reductionShaanxi
国家科技期刊平台
NSTL
万方数据
维普
