论文部分内容阅读
从林分的光环境、生物量、生产结构三方面入手,分析了黑荆人工林执行物质生产的群体结构。研究结果表明:林分的消光系数与林分叶量大致成反比关系。4年生林的总生物量为64.7t/hm~2,气干杆皮7.4t/hm~2,木材蓄积465m~3/hm~2。同化物的生长分配以树杆占比例最大,其次是树枝、树叶。竞争首先导致林分中层木分化,使中层木的比例减少,上层木和下层木比例增加。林分结构以上层木>中层木>下层木的比例时为佳,而实现这种比例结构,造林后的第4～6年进行适度的间伐是必要的。
Starting from three aspects of the light environment, biomass and production structure of the stands, the group structure of the material production of the Acacia crassicarpa plantation was analyzed. The results show that the extinction coefficient of forest stand is roughly inversely proportional to the amount of stand leaf. The total biomass of 4 - year - old forest was 64.7t / hm ~ 2, air - dried stem skin was 7.4t / hm ~ 2, and wood volume was 465m ~ 3 / hm ~ 2. Assimilation of the growth of the distribution of the largest proportion of tree stems, followed by branches, leaves. The competition first led to the differentiation of mid-level wood in the stands, reducing the proportion of mid-level wood and increasing the proportion of upper and lower levels of wood. The stand structure is better when the ratio of upper layer wood> middle layer wood> lower layer wood, and it is necessary to achieve this kind of proportion structure and moderate thinning in the 4th ~ 6th year after afforestation.