作 者 ：庞发虎,杨建伟,庞振凌,杜瑞卿*
期 刊 ：生态学报 2010年 30卷 12期 页码：3188~3197
Keywords:Populus simonii, ecophysiological indicators, environmental factor, comprehensive correlation coefficient analysis,
摘 要 ：为了揭示杨树生理生态指标与环境因子间综合复杂的关系，找出重要指标，在适宜土壤水分、中度干旱和严重干旱3 种土壤水分条件下研究水分胁迫对杨树生理生长变化的影响；在人工控制条件下，研究叶片净光合速率（Pn）、叶片气孔导度（Gs）随光合有效辐射（PAR)和 CO2浓度变化的反应关系；在中度干旱条件下，通过直接相关和综合相关分析，揭示各指标间相互影响的复杂关系。结果分析表明，水分胁迫对杨树生理生长变化有显著影响，是主要因子。在中度干旱条件下，对杨树有重要影响的因子依次为：光合有效辐射（PAR)、CO2浓度、大气温度（Ta）；能够反映杨树生理生态特性的重要指标依次为：耗水量、蒸腾速率（Tr）、呼吸速率（R）和净光合速率（Pn）.由此获得基本结论：杨树的生理生长变化受土壤水分、光合有效辐射（PAR)、大气CO2浓度和大气温度等多个环境因子的综合影响极其显著，其生理生长变化特征也宜采用多个指标来反应。直接相关分析不足以反映它们间的复杂关系，综合分析优于直接相关分析，分析方法科学合理，值得研究推广。
Abstract:To reveal the complex relationship between ecophysiological indexes and environmental factors of Populus simonii and find out the important indicators. Under three different conditions of adequate soil water, medium drought and severe drought, the impact of water stress on physiological growth change of Populus simonii was studied. Under the condition of manual control, net photosynthesis rate (Pn) stomatal conductance (Gs) and their changes were analyzed in response to active photosynthetic radiation and CO2 concentration; Under medium drought condition, the complex interaction between different indexes were revealed through direct correlation and integrated correlation analysis. The basic ideas of comprehensive correlation analysis were: (1) All the principal components of the variable group Y1, Y2,…, Yn executed vector synthesis according to proportion of variance contribution rate, and formated variable F1, similarly, from the main components of the variable group X1, X2,…, Xn, variable F2 was formated, then seek the F1 and F2 correlation coefficient to act as the integrated correlation coefficient R of variable group X and variable group Y. (2) Integrated correlation coefficient R was decomposed into the correlation coefficient Rij between Xi and Yj, Rij also divided into direct and indirect correlation coefficient between Xi and Yj, thus revealed the complex relationships. Important findings: (1) Under three different soil water content, the basic physiological and comprehensive indicators of Populus simonii, such as the net photosynthetic rate (Pn), transpiration rate (Tr), respiration rate (R) and total water consumption, were significantly different, which indicated that water stress had an important impact on growth of Populus simonii.(2) In manual control experiment net photosynthetic rate (Pn) in Populus simonii leaves increased with the increase of photosynthetic active radiation (PAR) under average atmospheric CO2 concentrations. When PAR was 0-500μmol?m-2s-1, Pn was the fastest-growing. This result indicated Populus simonii has better adaptability to strong light. Stomatal conductance (Gs) increased with the PAR increase. Pn increased with the CO2 concentration increase in certain PAR (1500μmol?m-2s-1) conditions, showing that the current atmospheric CO2 concentration could not provide sufficient raw materials to meet photosynthesis of Populus simonii, and improving the concentration of CO2 could significantly increase the net photosynthetic rate of Populus simonii.(3)The results of direct correlation analysis and comprehensive correlation analysis showed that active photosynthetic radiation (PAR), CO2 concentration and air temperature (Ta) had a remarkable influence on physiological growth of Populus simonii in moderate drought. Important indicators that can reflect ecophysiological characteristics of Populus simonii were as follows: water consumption, transpiration rate (Tr), respiration rate (R) and net photosynthesis rate(Pn). Physiological indicators and environmental indicators were highly correlated. In conclusion, changes in physiological growth of Populus simonii were the combined inflluence of soil water condition, active photosynthetic radiation,CO2 concentration and air temperature and its physiological growth characteristics should be studied by multi-index analysis.The comprehensive correlation coefficient analysis is scientific and rational and is superior to the direct correlation analysis.It is worthy of study and popularization.
全 文 ：