不同透光环境下红松光合色素含量的季节变动及应对策略

研究了辽东山区天然次生林内3种不同透光环境(强度透光、中度透光和弱度透光)下红松针叶光合色素(叶绿素a(Chl a)、叶绿素b(Chl b)、类胡萝卜素(Car)和叶绿素总量(Chl T))应对光环境季节变动做出的适应性调整。结果表明,随季节的变动(从春季至秋季),林分透光孔隙度逐渐减小。春季,透光度越大,红松叶绿素含量越高,Chl a/b值升高,Car/Chl T值降低;夏季,不同透光条件对红松光合色素含量无影响;秋季,各类透光条件下红松光合色素含量总体表现为升高的趋势,强度透光与中度透光条件红松针叶Chl a/b显著大于弱度透光,3种透光条件下红松Car/Chl T均降低。在春季红松开始生长前进行适当抚育,能提高光合色素含量,增强光合作用能力,促进生长。

The seasonal fluctuation and corresponding strategy of photosynthesis pigments content of Pinus koraiensis under different light environment

To assess the impact of different light environments on photosynthetic pigments contents, we compared chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoids (Car), total chlorophyll (Chl T) in three different light environments, including high-light, mid-light and low-light environments in a Pinus koraiensis during the growing season of 2011 on a montane forest site in eastern Liaoning Province, Northeast China. We found that the canopy openness decrease gradually from spring to autumn, and the contents of photosynthetic pigments changed correspondingly across season in P. koraiensis. Specifically, chlorophyll content and the ratio of Chl a/b increased while the ratio of Car/Chl T decreased in spring. In summer, there was no significant difference among different light environments for photosynthetic pigments contents. In autumn, photosynthetic pigments contents showed increase tendencies in three light treatments as compared with spring and summer seasons. However, the ratio of Car/Chl T decreased significantly in three different light environments in autumn. In addition, we also found that the ratio of Chl a/b was higher in the high-light and mid-light environments than that in the low-light. Overall, results from this study suggest that P. koraiensis should be taken light-transmittance management, such as thinning before the growing season began. Therefore, photosynthetic pigment contents would be higher in these light-transmittance treatments than that in the original light condition (control) in spring and autumn, which may increase photosynthesis in P. koraiensis and then promote the regeneration of P. koraiensis.