三种柞树苗期气体交换特性的研究

STUDIES ON CHARACTERISTICS OF GAS EXCHANGE FOR THREE OAK SPECIES IN NURSERY STOCK PERIOD

本文用气体交换法研究柞蚕林3个主要组成树种苗期的几个基本光合特性。蒙古栎具有较高的光补偿点,光饱和点及最大光合速率,但其量子光合效率较低,表明蒙古栎能比较有效地利用高强度的太阳辐射,而对弱光能利用效率较低;麻栎则相反;辽东栎既有较高的光饱和点及最大光合速率,同时又有较高的量子光合效率及较低的光补偿点,因而对高强度和低强度的光能利用效率都比较高。而且证明3个树种光合作用光响应模型以一种指数形式的方程最合理。我们还考察了辽东栎和麻栎在生长季不同时期光合特性的差异以及温度对3个树种光合特性的影响。

Several basic characteristics of photosynthesis of three oak species in the nursery stock period have been studied by gas exchange method in this paper. The results show 1. For Quercus mongolica, the light compensation point, light saturation point, and light-saturated rate of photosynthesis are relatively high, while its quantum efficiency is relatively low, indicating that it can use solar radiation with high intensity efficiently, but the efficiency of using weak light is low. Such photosynthetic characteristics are opposite in Q. acutissima. Both the light saturation point and light-saturated rate of photosynthesis are relatively hight, at the same time the quantum efficiency is also hight in Q. liaotungensis, but light compenation point is low. Therefore, it can use both high and low light energy efficiently. 2. It is provd that the exponential equation P_n=P_(max)·(1-e^(-aI/P_(max)))-R is the most rational for sinmulating photosynthetic response to light intensity in three oak species. 3. The differences of photosynthetic characteristics between Q. acutissima and Q. liaotugensis at various periods of growing season, and the influence of temperature on photosynthetic characteristics in three oak species have been also investigated.