不同光强下大青山几种树种光合速率和叶绿素荧光特性变化

Changes of Photosynthetic Rates and Chlorophyll Fluorescence Characteristics of Several Tree Species under Different Light Intensity in the Daqing Mountain

[目的]研究不同光强度下大青山几个树种光合速率和叶绿素荧光特性的变化。[方法]使用LI-COR6400便携式光合系统研究了不同光强度下大青山地区白桦(Betula platyphylla Suk.)、辽东栎(Quercus liaotungensis Koidz.)、蒙椴(Tilia mongolica Maxim.)、虎榛子(Ostryopsis davidiana Decaisne)和土庄绣线菊(Spiraea pubescens Turcz.)的光合速率和叶绿素荧光特性。[结果]NPQ、ETR、Fv′/Fm′等叶绿素荧光指标的光响应曲线在高光时都具有类似光合速率光响应曲线光饱和点的临界点,当光强度小于临界点光强度时,随着光强度变化其变化较大,而当大于临界点光强度时其变化较小或基本不变。NPQ光响应曲线临界点的光强度(QNPQ)能评价树木对高光的适应能力,根据QNPQ大小可以把被试树种分为3组,虎榛子[707μmol/(m2.s)]最强,其次为蒙椴[680μmol/(m2.s)]、辽东栎[654μmol/(m2.s)],土庄绣线菊[591μmol/(m2.s)]和白桦[405μmol/(m2.s)]最弱。根据被试的5种树木光合速率光补偿点的大小排序发现,白桦最大,虎榛子最小。[结论]5种被试树木中虎榛子既有对低光的适应性,又有对高光的适应能力,为大青山地区植树造林树种的选择和经营提供理论依据。

[Objective] The research aimed to study the changes of photosynthetic rates and chlorophyll fluorescence characteristics of several varieties of tree species under different light intensity in the Daqing Mountain.[Method] The photosynthetic rate and chlorophyll fluorescence characteristics of tree species,Betula platyphylla Suk.,Quercus liaotungensis Koidz.,Tilia mongolica Maxim.,Ostryopsis davidiana Decaisne and Spiraea pubescens Turcz.,were measured and studied in different light intensity by means of LI-COR6400 Portable photosynthesis system in Daqing Mountain.[Result] The results showed that the light response curves of chlorophyll fluorescence indices such as NPQ,ETR,Fv＇/Fm＇ all had a critical point as the light saturation point of photosynthetic rate.When the light intensity was less than that of the critical point,They changed great with the light intensity,while when it was more than that of the critical point,they had no change or a little.The light intensity of the critical point（QNPQ） in NPQ light response curve could evaluate the adaptability of different species of tree species to the greater light intensive.According to the values of QNPQ,the tested tree species could be divided into three groups,the most was Ostryopsis davidiana Decaisne[707 μmol/（m^2·s）],the weakest were Spiraea pubescens Turcz.[591 μmol/（m^2·s）]and Betula platyphylla Suk.[405 μmol/（m^2·s）],the middle were Tilia mongolica Maxim.[680 μmol/（m^2·s）],Quercus liaotungensis Koidz.[654 μmol/（m^2·s）].The light compensation point of photosynthetic rate of Betula platyphylla Suk.was the greatest in the 5 tested tree species,and the Ostryopsis davidiana Decaisne was the smallest.[Conclusion] The study indicated that Ostryopsis davidiana Decaisne is adapt to not only low-light but also high-light,which can provide the scientific basis for choosing and managing the forest planting tree species.