干旱和半干旱区生物结皮层及其覆盖土壤的蒸发特征  

Evaporation characteristics of biocrust layer and its covered soil in arid and semi-arid regions

作　　者：郭睿思 刘目兴[2] 易军[1] 张海林[1] 费远航 倪鑫 李琪[1] 李胜龙[1] GUO Ruisi;LIU Muxing;YI Jun;ZHANG Hailin;FEI Yuanhang;NI Xin;LI Qi;LI Shenglong(College of Urban&Environmental Science,Central China Normal University,Wuhan 430079,China;Key Laboratory for Geographical Process Analysis&Simulation,Hubei Province,Central China Normal University,Wuhan 430079,China)

机构地区：[1]华中师范大学城市与环境科学学院,武汉430079 [2]华中师范大学地理过程分析与模拟湖北省重点实验室,武汉430079

出　　处：《农业工程学报》2025年第6期117-127,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(42307414);中国博士后科学基金项目(2023M741309);湖北省自然科学基金项目(2023AFB916)。

摘　　要：生物结皮广泛分布于干旱和半干旱区,其对浅层土壤的水量平衡过程具有重要影响。为探究生物结皮层(0~2 cm)及其覆盖土壤(0~15 cm)的蒸发过程特征,该研究通过室内模拟蒸发和野外定位监测等方法,对黄土高原典型生物结皮(藻结皮和藓结皮)与裸沙土壤的蒸发特征进行对比研究。结果表明:不同类型生物结皮层对土壤蒸发过程的影响差异明显,整体上表现为藻结皮层促进土壤蒸发而藓结皮层抑制蒸发。其中在低蒸发强度(150 W)下,生物结皮层对蒸发具有显著的促进作用,藻结皮层和藓结皮层的平均蒸发速率(0.28和0.30 mm/h)分别较裸沙(0.25 mm/h)提升12.0%和20.0%;在高蒸发强度(275 W)下,藻结皮层的平均蒸发速率与裸沙相似,而藓结皮层(0.54 mm/h)较裸沙(0.62 mm/h)降低12.9%。原状土柱模拟蒸发试验结果显示,生物结皮覆盖土壤在不同含水率条件下蒸发过程差异显著,其中在低含水率(3.5%)条件下生物结皮蒸发速率均高于裸沙;而在高含水率(饱和)条件下,藓结皮表现为先抑制后促进蒸发,其在蒸发第1和2阶段的平均蒸发速率较裸沙降低12.2%,但在第3阶段较裸沙平均增加37.8%。此外,野外不同深度土壤含水量监测结果表明,生物结皮(特别是藓结皮)显著增加地表0~10 cm土壤含水量,但其20 cm处含水量却显著低于裸沙。综上,生物结皮层虽然对蒸发具有抑制作用,但其覆盖的表层土壤蒸发速率整体高于裸沙,从而加速表层土壤水分损失。作为荒漠区地表重要的特殊覆被层,生物结皮的形成改变表层土壤的理化性质,从而影响表层土壤蒸发特征,最终对水分短缺的干旱和半干旱区土壤水量平衡过程产生重要影响。Biocrust(biological soil crust)is one special type of the most important surface layer cover in the arid and semi-arid regions.There is also a strong impact on the water balance of surface soil.The biocrusts can rapidly fill the degraded patches to stabilize on the surface soil.Moreover,the biocrusts can also change the physicochemical properties of the surface soil,such as the bulk density,total porosity,field capacity,and organic matter content.This study aims to clarify the influence of the biocrust layer(0-2 cm)and its covered soil(0-15 cm)on evaporation in the Loess Plateau.A comparison was also made on the evaporation among the bare sand,cyanobacteria crusts(cyano-crusts),and moss crusts.Indoor simulated experiments were carried out to in-situ monitor the soil moisture.The results showed that there was a great variation in the effects of the different types of biocrusts on soil evaporation.The cyano-crust layer promoted evaporation,whereas,the moss crust layer inhibited it.Specifically,the biocrust layer has significantly enhanced the evaporation at the low intensity of evaporation(150 W).The average evaporation rates of the cyano-crust layer(0.28 mm/h)and moss crust layer(0.30 mm/h)were 12.0%and 20.0%higher than those of the bare sand(0.25 mm/h),respectively.Furthermore,the average evaporation rate of the cyano-crust layer was similar to that of the bare sand at high evaporation intensity(275 W).While the moss crust layer(0.54 mm/h)was 12.9%lower than that on the bare sand(0.62 mm/h).On the undisturbed soil columns,the average evaporation rate of cyano-crusts(0.18 mm/h)was 1.2 times higher than that of bare sand(0.15 mm/h)under low soil moisture.While the average evaporation rate of moss crusts(0.19 mm/h)increased by 26.7%,compared with the bare sand(0.15 mm/h).The cyano-crusts(0.25 mm/h)and moss crusts(0.30 mm/h)facilitated the evaporation with an average evaporation rate of 8.7%and 30.4%higher than those of bare sand(0.23 mm/h)under high soil moisture.While the moss crusts shared the significant stage be

关 键 词：生物结皮 土壤含水率 土壤蒸发 模拟蒸发试验 黄土高原 

分 类 号：S152.7[农业科学—土壤学] S157.1[农业科学—农业基础科学]