| 三峡库区岸边共存松栎树种水分利用策略比较 |
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| 引用本文： | 孙双峰,黄建辉,林光辉,韩兴国.三峡库区岸边共存松栎树种水分利用策略比较[J].植物生态学报,2006,30(1):57-63. |
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| 作者姓名： | 孙双峰 黄建辉 林光辉 韩兴国 |
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| 作者单位： | 1 中国科学院植被数量生态学重点实验室，北京 100093; 2 中国科学院研究生院，北京 100039 |
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| 基金项目： | 中国科学院知识创新工程项目;中国科学院"百人计划" |
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| 摘 要： | 对三峡库区木鱼岛上马尾松（Pinus massoniana）、槲栎（Quercus aliena）和栓 皮 栎（Q. variabilis）组成的针阔混交林成林和幼林的光合速率（Pn）、气孔导 度 （Gs）、清晨和中午水势（ψpd和ψmd）以及叶片稳定碳同位素（δ13C）进行了测定。实验结果表明：针叶树马尾松Pn、Gs均低于阔叶树槲栎和栓皮栎（差异达到极显著水平，p< 0.001），但马尾松内在水分利用效率（WUEi, Pn/Gs）却高于槲栎（p=0.003）和栓皮栎 （p=0.025）。反映了裸子植物和被子植物木质部不同的水力特性。针阔叶树幼树的Pn和Gs高于成年树，但 WUEi和δ13C却 低于成年树。表明水分利用效率与水分在树体内传输的距离有关。幼树属于挥霍型水分利用 策略，成年树属保守型水分利用策略。三峡大坝的建设所造成的生态环境的改变可能会对三 峡库区针阔混交林的演替产生一定的影响，但这需要长期的研究。
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| 关 键 词： | 三峡 松栎混交林 水分利用效率 水势 稳定碳同位素 |
| 收稿时间： | 2005-03-28 |
| 修稿时间： | 2005-09-29 |
CONTRASTING WATER USE STRATEGY OF CO-OCCURRING PINUS-QUERCUS TREES IN THREE GORGES RESERVOIR |
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| SUN Shuang-Feng,HUANG Jian-Hui,LIN Guang-Hui,HAN Xing-Guo.CONTRASTING WATER USE STRATEGY OF CO-OCCURRING PINUS-QUERCUS TREES IN THREE GORGES RESERVOIR[J].Acta Phytoecologica Sinica,2006,30(1):57-63. |
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| Authors: | SUN Shuang-Feng HUANG Jian-Hui LIN Guang-Hui HAN Xing-Guo |
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| Affiliation: | 1 Laboratory of Quantitative Vegetation Ecology, Chinese Academy of Sciences, Beijing 100093, China; 2 Graduate School of Chinese Academy of Sciences, Beijing 100039,China |
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| Abstract: | With the rise of water level, the construction of the Three_Gorges Dam may have significant impacts on plant carbon_water relation and ecosystem prope rties in this region. To understand how the plants in this region adapt to the c hanges in water environments, we measured gas exchange, water potential andδ13C of sapling and mature trees of three co_occurring coniferous and dec iduous spec ies: Pinus massoniana, Quercus variabilis and Q. aliena, all are dominant tree species in this region. The two deciduous broad_leaf trees (Q. variabilis a nd Q. aliena) exhibited higher photosynthetic (Pn) and stomatal conduc tance (Gs) than the evergreen conifer species (P. massoniana). The pre dawn water potential (ψpd) of P. massoniana was lower than that of the two broad_leaf species. Intrinsic water use efficiency (WUEi, Pn/Gs) of P. massoniana was higher than those of Q. variabili s and Q. aliena. However, the differences in carbon isotope ratio (δ13C) of leaves among species, which gives integrative information of WUE in growing seas on period, were not statistically significant. We also compared eco_physiologica l parameters between saplings and mature trees of these three species. The Pn and Gs values of the mature trees were significantly lower than t hose of the saplings. The mature trees showed lower ψpd value, but the difference between the mature trees and the saplings was not statistically significant. However, the WUEi values of all mature trees were significantly higher than those of the saplings. The δ13C values of mature trees showed more positive than those of corresponding saplings, indicating also higher WUE in the mature trees. From these results, we concluded that 1) P. massoniana showed different wa ter use strategies from two Quercus trees species, and 2) the mature trees of these three dominant tree species showed lower photosynthetic rate but higher WU E than those of their corresponding saplings. |
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| Keywords: | Three Gorges Pinus-Quercus community Water use efficiency Water potential Carbon isotope ratio |
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