I－69杨胶合板用材林密度及立地效应研究

Studies on the Stand Density and Site Effect of I 69 Poplar Plantation for Plywood

以胶合板材为培育目标，研究了Ｉ－６９杨胶合板用材林平均单株材积与造林密度和优势高的关系。分别不同林龄（６～１１ａ）建立了平均单株材积与造林密度及优势高的模型Ｖ＝ａ０Ｎａ１Ｈａ２０，通过生产弹性分析、边际产量分析，研究了密度效应及优势高效应，计算出了不同林龄林分的生产弹性值和边际产量，并且根据立地及密度效应模型研究了造林密度、林龄、立地指数对林分蓄积的影响。认为在长江中、下游地区营造Ｉ－６９杨胶合板用材林密度应适当减小，选择造林地时以立地指数大于等于２０ｍ林地为佳。

Taking developing plywood as the main objective, the relationship between average individual tree volume i.B. and stand dominant height and between average individual tree volume i.B. and silviculture density on Ⅰ 69 poplar ( Populus deltoides Bartr.cv. ‘Lux’) plantation was studied. Taking selected silviculture density and stand dominant height as independent variable, fitted models of average individual tree volume i.B. V=a 0N a 1 H a 2 0 for the stand of respective stand age from 6 to 11. With the elasticity of production and marginal production analysis,the silviculture density effect and stand dominant height effect and the amount of the elasticity of production and the marginal production were studied. In addition,based on the effect models of the stand site and silviculture density,the stand volume effected by silviculture density,stand age and site index were also studied. The research indicated that when the I 69 poplar plantation was cultivated for plywood,silviculture density should be lowered down properly. The optimum silviculture density is 156 or 204 trees/ha. And when selecting the land be used for cultivation,the site index of the land should be equal to or more than 20 m in the region of the middle reaches and the lower reaches of the Changjiang River.