Influence of long-term changes in climate and CO2 concentration on intrinsic water-use efficiency (iWUE), defined as the ratio between net photosynthesis (A) and leaf conductance (g), and tree growth remain not fully revealed in humid subtropical China, which is distinct from other arid subtropical areas with dense coverage of broadleaf forests. This study presented the first tree-ring stable carbon isotope (δ13C) and iWUE series of Pinus massoniana from 1865 to 2013 in Fujian province, humid subtropical China, and the first tree-ring width standard chronology during the period of 1836–2013 for the Niumulin Nature Reserve (NML). Tree-ring width growth was limited by precipitation in July-August (r = 0.40, p < 0.01). The tree-ring carbon isotope discrimination (Δ13C) was mainly controlled by the sunshine hours (r = -0.66, p < 0.001) and relative humidity (r = 0.58, p < 0.001) in September-October, a season with rapid latewood formation in this area. The iWUE increased by 42.6% and the atmospheric CO2 concentration (ca) explained 92.6% of the iWUE variance over the last 150 years. The steady increase in iWUE suggests an active response with a proportional increase in intercellular CO2 concentration (ci) in response to increase in ca. The contribution of iWUE to tree growth in the study region is not conspicuous, which points to influences of other factors such as climate.
Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China;Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China;Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden;Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China;Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden;Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China;Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China;Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China;Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China;Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China;Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China;Institute of Geography, Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
Recommended Citation:
Dawen Li,Keyan Fang,Yingjun Li,et al. Climate, intrinsic water-use efficiency and tree growth over the past 150 years in humid subtropical China[J]. PLOS ONE,2017-01-01,12(2)