移除和沙埋对沙土生物结皮土壤蒸发的影响  

Effects of Biological Crust Removal and Sand Mulching on Soil Evaporation in a Sandy Soil

作　　者：孟杰[1] 卜崇峰[1,2] 张兴昌[1,2] 孙占锋 

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]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]<中国水土保持>杂志社,河南郑州450003

出　　处：《水土保持通报》2011年第1期58-62,159,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"黄土水蚀风蚀交错区土壤结皮的时空发育特征及其土壤水文与侵蚀效应研究"(40701096);中国科学院西部之光项目"毛乌素沙地生物结皮的发育过程及其风蚀效应研究"(B28013200);陕西省自然科学基金项目"黄土风水蚀交错区土壤结皮的发育及其侵蚀效应"(SJ08D07)

摘　　要：干旱半干旱地区水分是植被恢复和演替的限制性生态因子,沙土生物结皮能降低水分入渗,造成土壤水分浅层化和加剧土壤水分时空分异,因此有必要采取措施进行适度干扰,以促进生态恢复和重建。土壤蒸发是天然降水无效损失的一个重要途径,研究生物结皮对土壤蒸发的影响十分必要。以陕北水蚀风蚀交错区沙土生物结皮为研究对象,分析了移除生物结皮和沙埋2种干扰下生物结皮类土壤水分蒸发特性。结果表明,移除生物结皮并不能起到显著地抑制土壤蒸发的作用(p>0.05),而沙埋对土壤蒸发具有显著地抑制作用(p<0.01),且随沙埋厚度的增加,蒸发抑制率提高。20mm沙埋的抑制蒸发作用最大,蒸发抑制率达到了58.15%。5mm和10mm沙埋的蒸发抑制率则分别为25.20%和28.29%,二者之间的差异未达到显著水平(p>0.05)。可见,沙埋对于改善土壤水分状况具有极积意义,但应控制沙埋的厚度。Soil water is one of limiting ecological factors for vegetation restoration and succession in arid and semiarid regions.The presence of biological crust on sandy soils limits water infiltration depth and reduces water availability for deep-rooted plants;meanwhile,the biological cover can affect greatly the spatial variability and redistribution of soil water.It is therefore necessary to apply proper disturbance on the crust to promote ecological restoration and rehabilitation.It may also be important to address the influences of biological crust on soil evaporation,which is a major part of soil water loss after natural rainfalls.In this study,soil evaporation features were studied after removal disturbance and sand burial disturbance on biological crust in a sandy soil of the Loess Plateau,China,which experiences severe crisscrossing water and wind erosion.The results show that removal of the crust did not effectively reduce soil moisture evaporation compared with control（p0.05）,while sand burial significantly decreased soil evaporation（p0.01）.Soil evaporation was increasingly reduced with the sand bed thickness.The sand burial depth of 20mm had the greatest inhibitive effect on soil evaporation reduction,and the cumulative evaporation was reduced by 58.15% at the end of the experiment.There was no significant difference between 5mm and 10mm sand burial depths（p0.05）,which reduced soil evaporation by 25.20% and 28.29%,respectively.The findings show that sand burial disturbance has positive effects on conserving soil water in the study area.

关 键 词：生物结皮 土壤蒸发 沙埋 水蚀风蚀交错区 

分 类 号：S152.7[农业科学—土壤学]