透光抚育对长白山阔叶红松林冠下红松光合作用的影响1）

摘要

The experiment was conducted to study the effects of crown thinning intensities on photosynthesis of Korean pine with nearly 15-year-old Korean pine forests through the growing season (May to October).The clear pattern of Pn-Q curves re-flected the adoption of Korea pine to local climate .The apparent quantum efficiency was significantly negatively correlated with total solar radiation (r=0.9, p<0.05); Temperature and rainfall explained 70%of variance of maximum photosyn-thetic rate, and dark respiration rate significantly negatively correlated with solar hours .There were clear patterns in rela-tionship between photosynthesis parameters and canopy density .To get higher productivity , the canopy density in 0-0.3, especially in 0.2-0.3 was the best , and the respiration rate was the lowest and photosynthesis rate was the highest .%以长白山阔叶红松林为研究对象，通过对不同冠层郁闭度冠下生长季节（5—10月份）红松光响应曲线的测定，研究透光抚育对红松光合作用的影响。结果显示：红松光合作用光响应曲线显著的季节变化模式反映了红松对当地水热等气候条件的适应性。表观量子效率与太阳辐射量呈显著负相关（ r＝0．9，p＜0．05），温度和降水解释了最大净光合速率季节变化的70％；暗呼吸速率与日照时间显著负相关（ r＝0．92，p＜0．05）。红松光合作用光响应曲线随冠层郁闭度变化模式清晰。红松生产力在0～0．3郁闭度组，特别是在0．2～0．3郁闭度组为最优，对应的红松最大净光合速率最优，暗呼吸速率最小。