生物多样性 ›› 2018, Vol. 26 ›› Issue (6): 564-571.DOI: 10.17520/biods.2017342

• 研究报告 • 上一篇    下一篇

基于稳定同位素技术的塔里木河下游不同林龄胡杨的水分利用来源

张江1, 李桂芳1, 贺亚玲2, 穆雨迪3, 庄丽1,*(), 刘红玲4,*()   

  1. 1 石河子大学生命科学学院新疆植物药资源利用教育部重点实验室, 新疆石河子 832003
    2 石河子大学医学院, 新疆石河子 832003
    3 华东师范大学生命科学学院, 上海 200241
    4 成都师范学院化学与生命科学学院, 成都 610101
  • 收稿日期:2017-12-31 接受日期:2018-05-03 出版日期:2018-06-20 发布日期:2018-09-11
  • 通讯作者: 庄丽,刘红玲
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    国家自然科学基金(31560177)

Water utilization sources of Populus euphratica trees of different ages in the lower reaches of Tarim River

Jiang Zhang1, Guifang Li1, Yaling He2, Yudi Mu3, Li Zhuang1,*(), Hongling Liu4,*()   

  1. 1 Key Laboratory of Xinjiang Phytomedicine Resource Utilization of Ministry of Education, College of Life Sciences, Shihezi University, Shihezi, Xinjiang 832003
    2 Faculty of Medicine, Shihezi University, Shihezi, Xinjiang 832003
    3 College of Life Sciences, East China Normal University, Shanghai 200241
    4 College of Chemistry and Life Science, Chengdu Normal University, Chengdu 610101
  • Received:2017-12-31 Accepted:2018-05-03 Online:2018-06-20 Published:2018-09-11
  • Contact: Zhuang Li,Liu Hongling
  • About author:

    # Co-first authors

摘要:

水分是制约很多陆地生态系统植物生长和繁殖的重要因素, 在干旱地区尤为明显。利用稳定同位素技术探究塔里木河下游不同林龄胡杨(Populus euphratica)的水分来源情况, 了解生态输水背景下荒漠河岸林的水分利用循环与利用策略, 可为生态输水提供科学依据, 同时也可对同类地区的生态恢复提供借鉴。本研究通过测定塔里木河下游胡杨茎干水和各潜在水源(土壤水、地下水)的稳定氢氧同位素值(δD、δ18O), 应用多源线性混合模型(IsoSource)分析了各潜在水源对不同林龄胡杨的贡献比例, 并结合3种林龄胡杨不同土壤深度含水量的变化, 分析了胡杨的主要吸水层位。结果表明: (1)不同林龄胡杨样地的不同深度区间上的土壤水δ18O值存在显著差异(P < 0.05): 胡杨幼龄木、成熟木、过熟木木质部δ18O分别为-7.83 ± 0.07‰、-8.53 ± 0.11‰、-9.36 ± 0.21‰; 而δD值不存在显著差异(P > 0.05)。可据此来推断胡杨的主要吸水层位。(2)总体上, 三种林龄胡杨土壤水δ18O值随土壤深度增加而减小, 并趋于接近地下水的δ18O值。其中, 0-60 cm土壤水受蒸发影响比较大, 其同位素组成经历了强烈的蒸发分馏过程, 土壤含水量极少, 土壤水δ18O值偏正。(3)不同林龄胡杨所利用的水分来源不同: 胡杨幼龄木对于地表80 cm以下的土壤水以及地下水均有一定程度的利用, 对80-140 cm、140-220 cm和220-340 cm的土壤水平均利用比率依次为16.2%、21.4%和24.6%, 对地下水平均利用比率为24.5%; 成熟木主要利用220-340 cm的土壤水及地下水, 平均利用比率分别为36.9%和42.3%; 过熟木主要利用140-340 cm的土壤水及地下水, 平均利用比率分别为32.8%和49.3%。

关键词: 氢氧稳定同位素, 水分利用来源, 土壤水, 林龄, 胡杨, 地下水

Abstract:

Water availability is one of the most important factors affecting the growth and reproduction of terrestrial plants, particularly in arid regions. Understanding the strategies of desert riparian plants to circulate and utilize water can reveal the scientific basis for ecological water conveyance engineering and contribute to planning ecological restoration of similar areas. In this study, we examined whether Populus euphratica trees of different ages in the lower reaches of Tarim River differed in their water sources by using the stable hydrogen and oxygen isotope technology. Specifically, for P. euphratica of different ages in the same habitat, we measured hydrogen and oxygen stable isotope ratios (δD and δ18O) values of xylem water and potential water sources (soil moisture and ground water). Then, we used multi-isotope mass balance analysis (IsoSource) to calculate the possible contributions of potential water sources to the total water content in plants. We found significant differences of δ18O value for soil moisture at different soil depths. Also, the δ18O values of young wood (-7.83 ± 0.07‰), mature wood (-8.53 ± 0.11‰) and over-mature wood (-9.36 ± 0.21‰), which were significantly different, while δD values did not differ statistically among the forest types. Furthermore, δ18O values of P. euphratica in three kinds of forest age became lower while the distance was deeper from soil surface and gradually approached to ground water on the whole. The shallow soil water in 0-60 cm was significantly affected by evaporation. The isotopic composition of soil water had experienced a strong evaporation and fractionation process. And soil water content was small, while δ18O values were large. Finally, our results showed that water utilization of P. euphratica of different ages came from different sources. The young wood of P. euphratica used an average of 16.2% of its water from 80-140 cm of the soil, 21.4% from 140-220 cm, and 24.6% from 220-340 cm and the average utilization ratio of ground water was 24.5%. In comparison, mature wood of P. euphratica mainly utilized the water from 220-340 cm of the soil and the ground water, with the utilization rate being 36.9% and 42.3%, respectively. Over-mature wood had water utilization ratios of 32.8% from 140-340 cm of soil and 49.3% of ground water.

Key words: stable oxygen and hydrogen isotopes, water utilization sources, soil water, forest age, Populus euphratica, ground water