摘要
森林生态系统在全球陆地水循环过程中扮演重要的角色,在保护水资源方面有关键作用。雪岭云杉(Picea schrenkiana)是我国天山森林生态系统的建群种,雪岭云杉的水分来源研究有助于理解植物对干旱区山地环境的适应。采用氧稳定同位素和IsoSource混合模型估算2200 m、1800 m和1450 m 3个海拔雪岭云杉生长季(4—9月)的水分来源并分析其动态变化。结果表明:(1)3个海拔土壤水的^(18)O在4月贫化,5—9月富集,1450 m海拔茎秆水δ^(18)O值在月份之间变化幅度最大,6—9月3个海拔雪岭云杉茎秆水^(18)O逐渐富集;(2)整个生长季0~0.2 m土壤水为3个海拔雪岭云杉贡献一半以上的水源,表层土壤水平均贡献率从高海拔到低海拔依次为61.37%、51.35%和58.42%,在5—6月雪岭云杉倾向平均利用各层土壤水,雪岭云杉生长季的水分吸收层没有明显地转移。雪岭云杉主要吸收0~0.2 m土壤水,在发生降雨时可以快速吸收水分,改善水文状况,减小极端降雨的危害,因此,加强雪岭云杉林的保护与抚育管理,可以有效提高了森林水源涵养能力,充分发挥其生态效益。
Picea schrenkiana is a typical constructive species in the Chinese Tianshan forest ecosystem with important ecological values.In this study,P.schrenkiana at three altitude gradients were selected to study its water sources during the growing season(June to September)in the natural forest conservation area of the northern slope of Tianshan Mountains.The hydrogen-oxygen stable isotope technique was used to determine theδ~(18)O values of xylem water and soil water levels.In addition,the relationships between xylem water or soil waterδ~(18)O values and altitude were analyzed,and the IsoSource model was used to quantify the water sources of P.schrenkiana at different altitudes.The results showed that:(1)theδ~(18)O of soil water at the three elevations were depleted in April and enriched from May to September.Theδ~(18)O values of stem water at 1450 m elevation showed the greatest variation between months,while theδ~(18)O of stem water was gradually enriched at the three elevations from June to September;(2)the 0-0.2 m soil water contributed more than half of the P.schrenkiana water requirement at the three elevations during the growing season,with the surface soil water average contribution rates of 61.37%,51.35%,and 58.42%in the high,middle,and low elevations,respectively.In May and June,P.schrenkiana tended to use soil water in all layers equally,and no significant shift in the plant water uptake was observed during the growing season.In addition,the water absorption of P.schrenkiana mainly occurred at 0-0.2 m soil water level,suggesting that it could rapidly absorb rainfall water,which can improve soil hydrology and reduce the damage caused by extreme rainfall.Therefore,strengthening the protection management of P.schrenkiana forests can effectively improve the water conservation capacity of forests and enhance their ecological benefits.
作者
田胜川
赵善超
郑新军
王玉刚
李彦
TIAN Shengchuan;ZHAO Shanchao;ZHENG Xinjun;WANG Yugang;LI Yan(State Key laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;Fukang Station of Desert Ecology,Chinese Academy of Sciences,Fukang 831505,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China;Natural Forest Protection Center of Xinjiang Uygur Autonomous Region,Urumqi 830001,Xinjiang,China)
出处
《干旱区研究》
CSCD
北大核心
2023年第3期436-444,共9页
Arid Zone Research
基金
国家自然科学基金(U1803342)
中国科学院西部之光项目(XBBS201001)
新疆林草局天然林保护工程项目(E1310102)。
