Journal of Geographical Sciences >
Long-term changes in the tree radial growth and intrinsic water-use efficiency of Chuanxi spruce (Picea likiangensis var. balfouriana) in southwestern China
Author: Wang Yang (1984-), PhD, specialized in dendrochronology and dendroecology. E-mail: wangy.10b@igsnrr.ac.cn
Received date: 2017-04-18
Accepted date: 2017-07-05
Online published: 2018-06-20
Supported by
National Basic Research Program of China ‘973’, No.2012CB956201
Key Program of National Natural Science Foundation of China, No.41630529
Copyright
Elevated CO2 level in the atmosphere is expected to improve the tree growth rates and intrinsic water-use efficiency (iWUE). Although current results inferring from tree rings found the tree growth decline in water-limited area, it is still unclear whether spruce trees in humid southwestern China benefit from the increasing CO2. In this study, tree-ring width data were used to investigate the tree radial growth rate of Chuanxi spruce (Picea likiangensis var. balfouriana). Moreover, combining with the tree-ring carbon isotope date, we analyzed the physiological responses of Chuanxi spruce to rising CO2 concentrations in the atmosphere (Ca) associated with climatic change in southwestern China. From 1851 to 2009, iWUE of Chuanxi spruce rose by approximately 30.4%, and the ratio of atmospheric CO2 to leaf intercellular CO2 concentration (Ci/Ca) showed no significant trend in the study area. The result suggested that Chuanxi spruce used an active response strategy when Ca was significantly increased. iWUE showed a significant increasing trend in parallel with tree radial growth, indicating that the increasing iWUE resulted in an increase in radial growth. These results suggest that spruce forests in southwestern China have not shown declining trends under increasing Ca and climate change scenarios, in contrast to trees growing in water-limited areas. Therefore, spruce forests benefit from the increasing CO2 in the atmosphere in the humid areas of southwestern China.
WANG Yang , ZHANG Yong , FANG Ouya , SHAO Xuemei . Long-term changes in the tree radial growth and intrinsic water-use efficiency of Chuanxi spruce (Picea likiangensis var. balfouriana) in southwestern China[J]. Journal of Geographical Sciences, 2018 , 28(6) : 833 -844 . DOI: 10.1007/s11442-018-1508-7
Figure 1 Location of the sample site and meteorological station |
Figure 2 Mean monthly temperatures and precipitation at the Jinchuan Meteorological Station from 1960 to 2008 |
Figure 3 Trends in annual total precipitation (a) and annual mean temperature (b) from 1960 to 2008. The grey dash line is the result of the linear regression of precipitation. |
Figure 4 Trends of the tree-ring width (a) and basal area increment (BAI) (b) for Chuanxi spruce from 1851 to 2009. Horizontal lines represent the mean value for the study period. The grey line is the result of the linear regression of BAI. |
Figure 5 The raw (δ13Craw) and corrected (δ13Ccor) chronologies for Chuanxi spruce from 1851 to 2009 |
Figure 6 Correlations between tree-ring width (a), BAI (b), δ13Ccor (c) and climate factors from 1960-2008. |
Figure 7 Trends in iWUE (a), Ca-Ci (b), Ci/Ca (c) and Ci (d) for Chuanxi spruce from 1851 to 2009. The grey dash lines are the results of linear regression. iWUE in different scenarios was shown in (a). |
Figure 8 Scatterplot of the annual values of iWUE versus Ca and the regression analysis results (grey line) |
Figure 9 The relationship between BAI and iWUE for 1851-2009. (a) raw values; (b) first-difference values |
The authors have declared that no competing interests exist.
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[4] |
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[5] |
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[6] |
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[7] |
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[8] |
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[9] |
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[10] |
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[11] |
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[12] |
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[13] |
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[14] |
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[15] |
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[16] |
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[17] |
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[18] |
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[19] |
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[20] |
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[21] |
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[22] |
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[23] |
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[39] |
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[41] |
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[44] |
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[45] |
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[46] |
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[47] |
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[50] |
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