【摘要】 研究表明,33年生人工油松纯林林冠分枝倾角分布于0～30°,弯曲率近于常数0.94.叶面积指数8.2.油松林反射率平均10.7%,透射率11.4%,潜热通量占净辐射59%,显热通量占26%,森林植物贮热量占4%,土壤热通量占11%,日平均波文比为0.48.油松林日蒸散量2.1mm.光能利用率0.14%.北京市现有油松林年固定9.29万tCO2,生产6.97万tO2,生物生产力每年每公顷5.48t.更多还原

【Abstract】 The structure of canopy, radiation field, energy balance and the coefficient utilization for solar energy of a Chinese pine plantation (33 -year-old, mean height 6.4m, DBH 8.6cm, 3 570stem/ha) were studied. The angle between the primary branches and their trunk varies mainly from 0 degree to 30 degree, and the value of mean curvature of the primary branches is 0.94. During the growing period, daily mean reflectance, transmitance and attenuation coefficient of the canopy are 10.7%, 11.4% and 1.378 6 respectively. Daytime (0600-1800) mean components of the energy balance of the stand were caculated basing on data collected during experiment period. The heat storage in the soil or in the trees comes to 11% or 4% of net radiation (Rn) of the stand. By means of Bowen ratio method, the flux of sensiblily (26%) and latent heat (59%) in daytime averages 85% of Rn and mean Bowen ratio 0.48 was obtained. The result of evapotranspiration of stand by energy balance method coincides with that by site water balance method in relatively long period. The coefficient of utilization of solar energy by the stand reaches 0.14% based on the total solar energy in a year.更多还原