透光抚育对红松生长及干形的影响

Influence of Crown Thinning on Korean Pine Growth and Stem Form

采用不同通光强度对红松林进行透光抚育,调查林分内各种指标,研究其树种组成结构、林分蓄积量和红松蓄积生产力。结果表明:红松幼树受周围灌木高度影响,当灌木平均高小于2.6 m时,红松幼树近5年高生长量随着灌木平均高的增加而增加,当灌木平均高大于2.6 m时,红松幼树近5年高生长量随着灌木平均高的减小而减小;当红松幼树周围3 m范围内的乔木株数大于4株时对红松幼树的高生长具有明显的抑制作用;红松人工林群落主要树种组成结构随着透光强度的增大趋于简单,但红松的优势地位有所增加;随着透光强度的增大,红松人工林中红松蓄积生产力呈递增趋势,群落蓄积量则表现为半透光群落最大;随着红松人工林林分密度的增加,红松尖削度越低,主干形质越好,同时分叉率也随之降低;红松的高径比对主干形质产生明显的影响,高径比越大,形数也越大。

In this paper,the korean pine forest was tended with different intensity of light,and a variety of indicators were investigated to study the species composition structure,forest volume and korean pine productivity. The results showed that korean pine saplings was influenced by the surrounding shrub height; when the average height of the shrubs was less than 2. 6 m,the high-growth of korean pine saplings increased as the average height of the shrubs increased; when the average shrub was more than 2. 6 m,the five-year height growth of korean pine saplings reduced as the shrub height decreased; when the number of trees within 3 m range of the korean pine saplings was greater than 4,the high-growth of korean pine saplings was significantly inhibited; the species composition of korean pine plantation communities tended to be simple as the light intensity increased,but the dominance of korean pine increased; with the increase of light transmission intensity,the korean pine plantations showed an increasing trend in the productivity,and community productivity was the maximum for the semi-light community; with the increase of the plantation density,the degree of korean pine taper decreased,trunk-shaped mass was better and the bifurcation rate decreased; the height to diameter ratio of korean pine had a significant impact on the trunk-shaped mass; the larger the aspect ratio,the greater the number of shapes.