华北土石山区不同造林密度的油松林结构与功能研究

Studys on the Configuration and Function of Different Density of Pines in Rocky Mountain Area of Northern China

对北京八达岭林场32年生5种造林密度(2000株/hm2、1500株/hm2、1200株/hm2、1000株/hm2、800株/hm2)阴坡油松林生物多样性、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;800株/hm2的阴坡油松林蓄积为108.19m3/hm2,是2000株/hm2油松林蓄积的1.22倍;不同密度油松林生态系统碳密度范围为107.43 t/hm2-174.30 t/hm2,平均碳密度为135.99 t/hm2,且随着密度增大而减小。油松林碳密度主要有三个部分组成: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,林地土壤的碳密度是相当可观大的,碳密度平均为90.34 t/hm2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?3.173;油松林地的稳渗速率、产流量随林分密度的增大而减小,这对增加该地区的径流水量、涵养水源能力具有重大意义。产沙量也随密度的增加而减少,这对选择油松800株/hm2作为最优林分密度是不利因素,但从北京的多年降雨来看,这种影响对我们选取油松在800株/hm2作为首选经营密度还是较小的。

The species diversity, carbon densities, 1500/hm^2, 1200/hm^2, 1000/hm^2 ,800/hm^2 ） water conservation and So on of five planting density （2000/hm^2, thirty - two old pines in the north slope of Badaling in Beijing were observed and determined. Studies were conducted in the different density. When the pine density is lower, the growth of pine have been becoming better, the species diversity of vegetation under forests was higher than that of other forests and had Quercus liaotungensis and others trees; The cumulation of 800/hm^2 was 108.19m^3/hm^2, and was 1.22 times of that of 2000/hm^2 cumulation; The range of carbon densities of different pine was 107. 43t/hm^2 - 174.30 t/hm^2 and the average carbon density was 135.99 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 90.34t/hm^2. The ratio of carbon density of above ground and under ground（ soil, root and litter） was average 1/3. 173 ;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/hm^2, but its effect is small for rainfall of many year in Beijing.