title: Contrasting water use pattern of introduced and native plants in an alpine desert ecosystem, Northeast Qinghai-Tibet Plateau, China.
abstract: Plant water use patterns reflect the complex interactions between different functional types and environmental conditions in water-limited ecosystems. However, the mechanisms underlying the water use patterns of plants in the alpine desert of the Qinghai-Tibet Plateau remain poorly understood. This study investigated seasonal variations in the water sources of herbs (Carex moorcroftii, Astragalus adsurgens) and shrubs (Artemisia oxycephala, Hippophae rhamnoides) using stable oxygen-18 isotope methods. The results indicated that the native herbs (C. moorcroftii, A. adsurgens) and one of the shrubs (A. oxycephala) mainly relied on water from the shallow layer (0-30 cm) throughout the growing season, while the introduced shrub (H. rhamnoides) showed plasticity in switching between water from shallow and deep soil layers depending on soil water availability. All studied plants primarily depended on water from shallow soil layers early in the season. The differences of water use patterns between the introduced and native plants are closely linked with the range of active root zones when competing for water. Our findings will facilitate the mechanistic understanding of plant-soil-water relations in alpine desert ecosystems and provide information for screening introduced species for sand fixation.
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China. Electronic address: wuhuawu416@163.com.
authors.forename: Huawu
authors.initials: H
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China. Electronic address: xyli@bnu.edu.cn.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Li
authors.affiliation: College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Huiying
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Cicheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Xiong
authors.initials: X
authors.lastname: Xiao
mesh_terms: D002681:China; D003889:Desert Climate; D017753:Ecosystem; D058865:Introduced Species; D018521:Plant Physiological Phenomena; D010944:Plants / Q000145:classification*; D058438:Water Cycle
keywords: IsoSource mixing model; Qinghai Lake; Root distribution; Sand fixation; Shrub–herb; Stable isotopes