img

官方微信

高级检索

中国沙漠 ›› 2012, Vol. 32 ›› Issue (3): 724-729.

• 生物与土壤 • 上一篇    下一篇

极端干旱区胡杨生长季水分利用效率变化特征研究

曹生奎1,2, 冯 起3, 司建华3, 常宗强3, 曹广超1,2, 陈克龙1,2   

  1. 1.青海师范大学 青藏高原环境与资源教育部重点实验室, 青海 西宁 810008;
    2.青海师范大学 生命与地理科学学院, 青海 西宁 810008;
    3.中国科学院寒区旱区环境与工程研究所, 甘肃 兰州 730000
  • 收稿日期:2011-10-29 修回日期:2011-12-14 出版日期:2012-05-20 发布日期:2012-05-20

Research on Characteristics of Water Use Efficiency Variations of Populus euphratica during the Growing Season in Extremely Arid Region of China

CAO Sheng-kui1,2, FENG Qi3, SI Jian-hua3, CHANG Zong-qiang3, CAO Guang-chao1,2, CHEN Ke-long1,2   

  1. 1.Ministry of Education Key Laboratory of Qinghai-Tibet Plateau Resources and Environment, Qinghai Normal University, Xining 810008, China;
    2.College of Life and Geography Sciences, Qinghai Normal University Xining 810008, China;
    3.Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2011-10-29 Revised:2011-12-14 Online:2012-05-20 Published:2012-05-20

摘要: 在干旱区的极端环境,植物能否适应当地的极限环境条件,最主要的是看它们能否很好地协调碳同化和水分耗散之间的关系,也就是说植物水分利用效率是其生存的关键因子之一。 就生长季胡杨叶片稳定碳同位素组成(δ13C)、胡杨叶片水分利用效率及其影响因素进行了研究。结果表明,生长季胡杨叶片δ13C值在-28.16‰±0.23‰~-26.82‰±0.22‰间变化,平均值为-27.70‰±0.13‰。胡杨各月水分利用效率在84.81±2.23~(70.97±2.40)μmolCO2·mmol-1H2O间变化,平均值为(75.69±1.31)μmolCO2·mmol-1H2O;胡杨水分利用效率变化趋势是逐渐降低。最高值出现在5月,而后不断降低,7月达到最低值。造成这种变化的原因是叶片营养物亏缺导致的叶片光合速率的减小和气温升高、土壤含水量减小以及地下水埋深加深共同导致的气孔导度的变化。

关键词: 胡杨, 水分利用效率, 稳定碳同位素, 额济纳绿洲, 极端干旱区

Abstract: In extremely arid environment, whether plants can adapt to the extreme environment or not depends mainly on whether they can finely harmonize the relation between carbon assimilation and water evapotranspiration. That is, water use efficiency is a key factor. We studied the variations of foliar δ13C values, water use efficiency and their affecting factors during the plant growing season. Results showed that the foliar δ13C values ranged from -28.16‰±0.23‰ to -26.82‰±0.22‰, and the means were -27.70‰±0.13‰. The monthly water use efficiency of P. euphratica ranged from (84.81±2.23)μmolCO2·mmol-1H2O to (70.97±2.40)μmolCO2·mmol-1H2O, and the mean was (75.69±1.31)μmolCO2 mmol-1H2O. The water use efficiency of P. euphratica decreased continuously during the growing season. The highest value of water use efficiency appeared in May, and the lowest value appeared in July. The causes for this trend were reduction of photosynthetic rates resulting from foliar nutrimental deficit and variations of stomata conductance caused by air temperature raising, soil content water decreasing and groundwater level falling.

Key words: Populus euphratica, water use efficiency, stable carbon isotope, Ejina oasis, extremely arid region

中图分类号: