Precipitation regulates plant gas exchange and its long-term response to climate change in a temperate grassland  

作　　者：Bing Song Shuli Niu Shiqiang Wan 

机构地区：[1]Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Datun Road,Chaoyang District,Beijing 100101,China [2]University of Chinese Academy of Sciences,Yuquan Road,Beijing 100049,China [3]Key Laboratory of Plant Stress Biology,College of Life Sciences,Henan University,Kaifeng,Henan 475004,China

出　　处：《Journal of Plant Ecology》2016年第5期531-541,共11页植物生态学报（英文版）

基　　金：National Natural Science Foundation of China(31000227);Ministry of Science and Technology of China(2013CB956300).

摘　　要：Aims Climate change largely impacts ecosystem carbon and water cycles by changing plant gas exchange,which may further cause positive or negative feedback to global climate change.However,long-term global change manipulative experiments are seldom conducted to reveal plant ecophysiological responses to climatic warming and altered precipitation regimes.Methods An 8-year field experiment with both warming and increased precipitation was conducted in a temperate grassland in northern China.We measured leaf gas exchange rates(including plant photosynthesis,transpiration and instantaneous water use efficiency[WUE])of two dominant plant species(Stipa sareptana var.krylovii and Agropyron cristatum)from 2005 to 2012(except 2006 and 2010)and those of other six species from 2011 to 2012.Important Findings Increased precipitation significantly stimulated plant photosynthetic rates(A)by 29.5%and 19.9%and transpiration rates(E)by 42.2%and 51.2%for both dominant species S.sareptana var.krylovii and A.cristatum,respectively,across the 8 years.Similarly,A and E of the six plant functional types were all stimulated by increased precipitation in 2011 and 2012.As the balance of A and E,the instantaneous WUEs of different plant species had species-specific responses to increased precipitation.In contrast,neither warming nor its interaction with increased precipitation significantly affected plant leaf gas exchange rates.Furthermore,A and E of the two dominant species and their response magnitudes to water treatments positively correlated with rainfall amount in July across years.We did not find any significant difference between the short-term versus long-term responses of plant photosynthesis,suggesting the flexibility of leaf gas exchange under climate change.The results suggest that changing precipitation rather than global warming plays a prominent role in determining production of this grassland in the context of climate change.

关 键 词：GRASSLAND leaf gas exchange PHOTOSYNTHESIS PRECIPITATION TRANSPIRATION WARMING water use efficiency 

分 类 号：P46[天文地球—大气科学及气象学]