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中国沙漠 ›› 2017, Vol. 37 ›› Issue (4): 714-723.DOI: 10.7522/j.issn.1000-694X.2016.00091

• 生物与土壤 • 上一篇    下一篇

红砂(Reaumuria soongorica)对大气CO2浓度升高及降水变化的光合生理响应

种培芳, 姬江丽, 李毅, 单立山, 苏世平   

  1. 甘肃农业大学 林学院, 甘肃 兰州 730070
  • 收稿日期:2016-04-28 修回日期:2016-06-08 出版日期:2017-07-20 发布日期:2017-07-20
  • 作者简介:种培芳(1977-),女,甘肃永登人,教授,博士,主要从事荒漠植物的生理生态研究。E-mail:zhongpf@gsau.edu.cn
  • 基金资助:
    国家自然科学基金项目(41461044,31360205,41361100)

Photosynthetic Physiology Responses to Elevated CO2 Concentration and Changing Precipitation in Desert Plant Reaumuria soongorica

Chong Peifang, Ji Jiangli, Li Yi, Shan Lishan, Su Shiping   

  1. College of Forestry, Gansu Agricultural University, Lanzhou 730070, China
  • Received:2016-04-28 Revised:2016-06-08 Online:2017-07-20 Published:2017-07-20

摘要: 未来大气CO2浓度的显著升高将引起降雨格局的变化,这必将对荒漠生态系统产生严重影响。研究CO2浓度及降水变化对荒漠优势植物的影响有助于预测荒漠生态系统对全球气候变化的响应。以荒漠优势植物红砂(Reaumuria soongorica)2年生苗木为试材,采用开顶式CO2控制气室模拟CO2浓度变化(350、550、700 μmol·mol-1),研究了降水变化(-30%、-15%、0、+15%、+30%)及其与CO2的协同作用对红砂光合特性及水分利用的影响。结果表明:CO2浓度增加可显著提高红砂的光合速率,短时高浓度CO2下红砂光合能力对水分的适应性较广,在降雨增加或减少时均表现出光合速率的增加,但长时高CO2浓度会导致红砂光合能力下降,出现光合适应现象。高浓度CO2下,红砂的蒸腾速率和气孔导度均有所下降,但降水的增加可抑制这种作用,有一定的补偿作用。CO2增加会显著提高红砂的水分利用效率,降雨越少这种作用越明显,但长期CO2作用会使这种效应有所减小。由此说明,未来CO2浓度升高可在一定程度上提高红砂的光合能力,尤其是在降雨减少时因CO2增加会提高水分利用效率而增强其抗旱性,从而增强红砂对未来暖干化气候的适应能力。

关键词: CO2, 降雨量, 光合生理, 水分利用效率, 红砂(Reaumuria soongorica)

Abstract: Precipitation will be changed by elevated atmospheric CO2 concentration in the future,which will seriously affect on the desert ecosystem.Our objective was to determine the interactive effects of elevated CO2 concentration and changing precipitation on photosynthetic physiology of Reaumuria soongorica which is dominant species of desert,in order to evaluate the response of desert ecosystem to future climate change.Open top chambers were used to simulate the elevated CO2 concentration (350,550,and 700 μmol·mol-1) and changing precipitation (30%,15%,0,+15%,+30%).The photosynthetic physiology indexes such as net photosynthetic rate,transpiration rate,stomatal conductance and water use efficiency of R.soongorica seedlings were measured in June,July and August.The results showed that,with increased CO2 concentration,net photosynthetic rate of R.soongorica increased obviously whether precipitation increased or decreased,which meant that the photosynthetic capacity of R.soongorica had a wide adaptability to precipitation under short elevated CO2.But photosynthetic capacity of R.soongorica decreased under long elevated CO2 and photosynthetic acclimation occurred during August.Transpiration rate and stomatal conductance decreased with increased CO2 concentration,but the results were opposite with increased precipitation because of the compensation.Wateruse efficiency increased significantly with increased CO2 concentration,especially under decreased precipitation treatment,but this reaction was smaller under long elevated CO2 than under short elevated CO2.The results suggest that at ambient CO2 levels,photosynthetic ability of R.soongorica increases with precipitation increasing,and drought resistance increases with water use efficiency increasing under decreased precipitation,which enhance the ability of R.soongorica to climate warming and rying in the future.

Key words: CO2, precipitation, photosynthetic physiology, water use efficiency, Reaumuria soongorica

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