北京山区不同密度油松结构与功能研究

Studies on the Configuration and Function of Different Density Pine in Rocky Mountain Area of Beijing

对北京八达岭林场32a生5种造林密度阳坡油松林生物多样性、蓄积量、碳密度、水源涵养等功能进行调查与实验，结果表明：随着林分密度的减小，林木生长状况良好，林下植被层各种生物多样性指数较其它林分高，并伴随着出现辽东栎等其它栎类更树种的生长；1200株／hm^2的油松林蓄积最大为95．53m^3／hm^2，但从单株蓄积量来看，不同密度的油松林单株蓄积随着油松林密度的减小而增大，油松800株／hm^2的单株蓄积为0．1017m^3／hm^2，是2000株／hm^2单株蓄积的3．17倍。不同密度油松林生态系统碳密度范围为78．87～142．13t／hm^2，平均碳密度为119．14t／hm^2，且随着密度增大而减小。油松林碳密度主要有3个部分组成：植被层、枯落物层和土壤层，其空间部分为土壤层〉植被层〉枯落物层，林地土壤的碳密度平均为79t／hm^2以上，地上部分碳密度与地下（包括土壤、树根和死地被物）碳密度之比平均为1／3．30；油松林地的稳渗速率、产流量随林分密度的增大而减小，这对增加当地的径流水量、涵养水源能力具有重要意义。产沙量也随密度的增加而减少，这对选择油松800株／hm^2作为最优林分密度是不利因素，但从北京的多年降雨来看，这种影响对选取油松在800株／hm^2作为首选经营密度还是较小。

The species diversity,carbon densities, water conservation and so on of thirty-two old pine of the south slope＇s five planting density were observed and determined at Badaling in Beijing. Studies were conducted on the different density, with smaller density of forests,the growth of pine have been becoming better and better,which the species diversity of vegetation under forests was higher than that of other forests and had Quercus liaotungensis and others trees; The biggest cumulation is 95.53 m^3/hm^2 of 1 200 trees/hm^2 pine forest,but individual cumulation of 800 trees/hm^2 is 0. 101 7 m^3/hm^2 ,and is 3.17 times of cumulation of 2 000 trees/hm^2 , which individual cumulation increases with the lessen of pine density. The range of carbon densities of different pine was 78.87-142.13 t/hm^2 and the average carbon density was 119.14 t/hm^2 ,which reduced with the augmentation of density. The carbon densities of pine were made of vegetation, litter and soil layer, the spatial distribution sequence of carbon storage ranked as soil layer〉vegetation layer〉litter layer,and the carbon density of soil was magnitude, which the carbon density was above of 90.34 t/hm^2. The ratio of carbon density of above ground and under ground （soil,root and litter） was average 1/3.30;The permeating rate and runoff reduced with increasing densities,which is magnitude signification of adding runoff and water conservation. The stands reduced with increasing densities,which is disadvantage factor for choosing the furthest density of 800 trees/hm^2,but its effect is small for rainfall of many year in Beijing.