黄土高原水蚀风蚀交错区生物结皮对灌草生态系统水分耗散的影响  

Effects of Biocrusts on Water Evapotranspiration of Shrub-Grass Ecosystem in Water-Wind Erosion Crisscross Region of Loess Plateau

作　　者：张旭东 杨光 赵允格 澹台彧 刘宁 鱼舜尧 ZHANG Xudong;YANG Guang;ZHAO Yunge;TAN Taiyu;LIU Ning;YU Shunyao(College of Natural Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;Wuqi Meteorological Bureau,Yan’an,Shaanxi 717600,China)

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]西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]吴起县气象局,陕西延安717600

出　　处：《水土保持学报》2024年第5期184-191,202,共9页Journal of Soil and Water Conservation

基　　金：国家重点研发计划项目(2022YFF1300802);国家自然科学基金项目(41830758,42377357)。

摘　　要：[目的]为研究生物结皮对灌草生态系统水分耗散的影响。[方法]采用原状土柱试验,以裸土为对照,设置灌草(单株灌木-20%盖度草本)、灌草-30%生物结皮和灌草-50%生物结皮3个处理,研究生物结皮对灌草生态系统水分耗散的影响。[结果]模拟30 mm降水12 h后,灌草-生物结皮处理0-20 cm土层水分含量较裸土处理平均提高15.4%,较灌草处理平均提高12.8%。与裸土相比,灌草及灌草与2个盖度生物结皮处理显著增加土壤水分耗散,其中灌草处理较裸土增加120.3%,灌草-生物结皮较裸土平均增加116.5%。生物结皮降低灌草生态系统的水分耗散。与灌草处理相比,灌草-生物结皮水分耗散平均降低1.7%,降低程度与生物结皮盖度、时段及土层深度有关。其中,灌草-50%生物结皮的水分耗散量较灌草-30%生物结皮处理降低13.4%。生物结皮对灌草生态系统水分耗散的降低作用在雨后1~4天表现明显。生物结皮对灌草生态系统水分耗散的降低主要取决于20-45 cm土层耗散的降低。与灌草处理相比,灌草-生物结皮的0-20 cm土层水分蒸散损耗平均提高14.4%,而20 cm以下土层水分耗散平均降低15.5%。[结论]30 mm降雨量条件下生物结皮降低灌草生态系统的水分耗散,有利于缓解风蚀水蚀交错区灌草植被的水分亏缺。研究结果揭示生物结皮对灌草生态系统水分耗散影响,可为旱区生态恢复提供理论依据。[Objective]To determine the effect of biological soil crusts(biocrusts)on water evapotranspiration of the shrub-grass ecosystem.[Methods]The effect of biocrusts on water evapotranspiration of the shrub-grass ecosystem in water-wind erosion crisscross region of Loess Plateau was investigated by using original soil columns of field condition.In the study,the bare soil column was used as control,and three treatments were set up.The three treatments were shrub-grass(single plant shrub-20%grass),shrub-grass-30%biocrusts and shrub-grass-50%biocrusts.[Results]The results showed that after 12 hours of simulated 30 mm precipitation infiltration,water content of 0-20 cm soil layer in the shrub-grass-biotic crust treatment was 15.4%higher than that in the bare soil treatment and 12.8%higher than that in the shrub-grass treatment.Compared with bare soil,soil water evapotranspiration of shrub-grass and shrub-grass with two level of biocrusts’coverage significantly increased.Among them,soil water evapotranspiration of shrub-grass treatment increased by 120.3%compared to bare soil,while shrub-grass-biocrusts increased by 116.5%on average.Biocrusts reduced soil water evapotranspiration of the shrub-grass ecosystem.Compared with the shrub-grass treatment,soil water evapotranspiration of the shrub-grass-biocrusts decreased by 1.7%on average.The degree of reduction of evapotranspiration was related to the coverage of biocrusts,period and soil depth.Among them,the water evapotranspiration of shrub-grass-50%biocrusts was 13.4%lower than that of shrub-grass-30%biocrusts.The reduction of water evapotranspiration of shrub-grass ecosystem caused by biocrusts was obvious during the first 1~4 days after rain.The reduction of water evapotranspiration of shrub-grass ecosystem caused by biocrusts mainly related to the evapotranspiration of 20-45 cm soil layer.Compared with the shrub-grass treatment,the water evapotranspiration loss of the 0-20 cm soil layer of the shrub-grass-biocrust treatment increased by 14.4%on average,while the water d

关 键 词：生物结皮 灌草生态系统 水分分布 蒸散发 土壤水分 

分 类 号：S157[农业科学—土壤学]