以甘肃酒泉地区种植1~4年的甘草(Glycyrrhiza uralensis Fiach)耕地和裸地(CK)为研究对象,通过测定其地表粗糙度、土壤含水率、风蚀量、地上生物量等指标,探索甘草植被对地表风蚀的影响,以及抗风蚀的内在机理。结果表明:在整个风蚀季节,样地风蚀表现为:秋末冬初风蚀较大、冬季较小,春季又增强的"U"型曲线模式;随着生长年限的增加,甘草地上生物量显著提高,甘草地表粗糙度和表层(0-5cm)土壤含水率分别比裸地提高12~55倍和27%~148%,而其土壤风蚀量较裸地下降10%~78%。甘草植被减少土壤风蚀主要通过甘草地上枯枝落叶覆盖地表,造成地表粗糙度和表层土壤含水率增大,相应地减弱了风对地表的直接吹蚀,提高了地表砂粒的起动风速,从而使得种植甘草耕地的抗风蚀能力显著提高。
Regarded Glycyrrhiza uralensis land and bare land in Jiuquan Gansu province as research objects,and conducted the influences of Glycyrrhizauralensisvegetation on dynamic changes of soil wind erosion and erosion-resistance mechanism through measuring their aerodynamic roughness of soil surface,soil moisture content,soil loss and above ground biomass.The results showed that:During the whole wind erosion season,the amount of soil loss was big in late autumn and beginning winter,then became very small in winter,and once again became higher when spring came,the dynamic curved line of soil wind erosion liked"U"shape.With extension of growing years,the above ground biomass(or amount of dry branches and fallen leaves)of Glycyrrhiza uralensis community had a significant increase,the aerodynamic roughness of soil surface increased by 12~55times,the soil moisture content in soil surface(0-5cm)increased by 27%~148%,soil wind erosion significantly decreased by 10%~78%compared with the bare land.The possible mechanism of wind erosion resistance by planting Glycyrrhiza uralensis was that the above-ground dry branches and fallen leaves of Glycyrrhiza uralensis covered surface of land,which increased roughness of soil surface and topsoil moisture content,reduced the wind speed on soil surface and increased the starting wind speed for soil sand grain.As a result,the erosion-resistance ability of Glycyrrhiza uralensis land was increased significantly.