黄土高原沟壑区藻类结皮的水土保持效应

从降雨径流、水分蒸发两方面探讨黄土高原沟壑区藻类结皮的水土保持效应。结果表明:①藻类结皮可显著增加0-10cm土层内土壤孔隙度,最大增加幅度总孔隙度为7.4%,毛管孔隙度为14.2%;对更深土层的土壤孔隙度无显著影响。②荒草坡、樟子松林和油松林3种植被类型下,有藻类结皮试验区径流量与无结皮对照区有显著差异,径流量分别减少了28.1%～32.5%、34.4%～43.1%和30.8%～31.6%。③3种植被类型下,藻类结皮的土壤侵蚀量与无结皮对照土壤侵蚀量有显著差异,分别比无结皮区土壤侵蚀量减少了58.8%～70.6%,48.9%～62.6%和38.3%～57.1%。④通过逐步回归分析,建立了不同植被类型下藻类结皮的径流量、土壤侵蚀量与降雨因子的回归方程。⑤藻类结皮对土壤水分变化的影响土层为20-60cm,在该范围内藻类结皮的土壤含水量显著高于无结皮区。

Effects of Soil and Water Conservation of Algae Crust in Hilly and Gully Regions on Loess Plateau

The effect of soil and water conservation of algae crust widespread in hilly and gully regions on Loess Plateau had been researched from two aspects which were rainfall infiltration-runoff and evaporation of soil water.The results were as follows: ①Algae crust could increase the 0-10 cm depth soil porosity.The maximum increase of total porosity was 7.4%,and the capillary was 14.2%.Algae crust had no significant effect on the soil porosity of the deeper layer.②In wasterland,mongolian scotch pine and Chinese pine forest,the runoff between the algae crust and non-crust had a significant difference.Compared with the runoff of non-crust,the runoff of algae crust in the three types of vegetation reduced by 28.1%～32.5%,34.4%～43.1% and 30.8%～31.6%.③In the three types vegetation,the amount of soil erosion between algae crust and non-crust had a significant difference.Compared with the amount of soil erosion of non-crust,the amount of soil erosion of algae crust in the three types of vegetation reduced by 58.8%～70.6%,48.9%～62.6% and 38.3%～57.1%.④By stepwise regression analysis,the different regression equations between runoff,soil erosion of algae crust and rainfall factor in different vegetation types could be obtained.⑤The soil moisture of 20-60 cm depth could be affect by algae crust.In this depth the soil moisture of algae crust was significantly higher than non-crust zone.