摘要
多枝柽柳(Tamarix ramosissima)灌丛是石羊河下游防风固沙林的重要组成,对绿洲免受风沙灾害侵袭发挥着关键作用。由于区域水文环境的恶化,多枝柽柳灌丛大面积退化死亡,亟需人工恢复,但其季节水分来源尚不清楚。为此,基于氢氧稳定同位素示踪技术,运用IsoSource模型,定量分析了不同衰退程度多枝柽柳灌丛的水分利用策略。结果表明:2016年石羊河下游降雨以小于5 mm小降雨事件为主,降雨氧稳定同位素值(δO)的季节效应明显。降水线方程为氢稳定同位素氘值δD=6.46δO-5.11,R^(2)=0.87。整体上,不同衰退程度多枝柽柳灌丛土壤水分在夏季较低,秋季略为恢复。由于衰退程度越严重蒸腾耗水越低,生长季多枝柽柳灌丛土壤水分大小排序为重度(3.48%)>极重度(2.69%)>中度(1.97%)>轻度(1.87%)。降雨与土壤水δD的变化关系分析表明,6—10月降雨对衰退多枝柽柳灌丛土壤水补给贡献较大。土壤水、降水、地下水是不同退化程度多枝柽柳灌丛的潜在水源。受春季蒸发损失小,冠层截留少,以及土壤生物结皮的综合影响,不同衰退阶段多枝柽柳春季对降水的平均利用比例达40.63%,大小排序为重度衰退(58.5%)>中度衰退(41.7%)>轻度衰退(39.3%)>极重度衰退(23%)。春季到秋季衰退多枝柽柳灌丛趋向于利用可靠的深层地下水。随生境水分可获得性的变化,不同衰退程度多枝柽柳选择性利用降雨、土壤水、地下水。虽然能勉强维持生存,但石羊河下游衰退多枝柽柳灌丛有被红砂(Reaumuria soongarica)等超耐旱小灌木替代的趋势。建议干旱区人工植被建设应以水定绿,灌草结合,少选择乔木、大灌木等高耗水植物种作为固沙造林树种。
T.ramosissima nebkhas is an important component of wind-proof and sand-fixing forest in the lower reaches of Shiyang River,which plays a key role in protecting the oasis from sand disaster.Due to the deterioration of regional hydrological environment,a large area of T.ramosissima nebkhas has been degraded and died,which is in urgent need of artificial restoration,but its seasonal water source is not clear yet.In this paper,IsoSource model was used to quantitatively analyze water use strategies of Tamarix ramosissima shrub with different decline degrees based on hydrogen and oxygen stable isotope tracer technique.The results showed that the precipitation line equation in the lower reaches of Shiyang River in 2016 wasδD=6.46δO-5.11,R^(2)=0.87.Rainfall is mainly small rainfall events less than 5 mm,and the seasonal effect of rainfallδO is obvious.Soil moisture of T.ramosissima nebkhas with different degrees of decline was lower in summer and slightly recovered in autumn.The more severe the recession,the lower the water consumption.In the growing season,the order of soil moisture in T.ramosissima nebkhas was severe(3.48%)>extremely severe(2.69%)>moderate(1.97%)>mild(1.87%).The relationship between rainfall and soil moistureδD showed that rainfall from June to October contributed significantly to soil water supply in T.ramosissima nebkhas.Soil water,precipitation,groundwater were the potential sources of T.ramosissima nebkhas with different degrees of degradation.Due to the low evaporation loss,less canopy interception and soil biological crusts,the average proportion of precipitation utilization by T.ramosissima nebkhas in spring was 40.63%,and the order was severe recession(58.5%)>moderate recession(41.7%)>mild recession(39.3%)>very severe recession(23%).The decline of T.ramosissima nebkhas from spring to autumn tended to utilize reliable deep groundwater.Along with the water availability of habitat,T.ramosissima nebkhas in different degrees of decline selectively used rainfall,soil water and groundwater,which r
作者
赵鹏
徐先英
姜生秀
徐高兴
柴成武
张逸君
马玉莲
戚福俊
高德才
张国平
ZHAO Peng;XU Xianying;JIANG Shengxiu;XU Gaoxing;CHAI Chengwu;ZHANG Yijun;MA Yulian;QI Fujun;GAO Decai;ZHANG Guoping(State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating,Gansu Desert Control Research Institute,Lanzhou 730070,China;Key Laboratory of Desert and Desertification,Northwest Institute of Eco-environment and Resources,Chinese Academy of Science,Lanzhou 730010,China;Collaborative Innovation Center for Western Ecological Safety,Lanzhou University,Lanzhou 730010,China;Gulang County Haizitan forest field,Gulang 733100,China)
出处
《生态学报》
CAS
CSCD
北大核心
2022年第17期7187-7197,共11页
Acta Ecologica Sinica
基金
甘肃省科技重大专项社会发展领域项目(21ZD4FA010)
中国科学院沙漠化与沙漠化重点实验室开放课题项目(KLDD-2020-017)
甘肃省科技计划项目(20JR5RA091,20YF3FA008)。
关键词
多枝柽柳灌丛
土壤水
降水
地下水
水分来源
稳定氢氧同位素
Tamarix ramosissima nebkhas
soil water
precipitation
groundwater
water source
stable hydrogen and oxygen isotopes
