明溪县天然常绿阔叶林研究Ⅰ.面积动态和转型

以明溪县森林资源清查体系的天然常绿阔叶林固定样地的初查、复查资料为基础 ,对间隔1 1 a的天然常绿阔叶林的变化和转型进行分析 .结果表明 :1 985年的天然常绿阔叶林 ,在 1 1 a中转型率达到 37.4% ,年均转型率为 4.2 % ;其它林型 (人工林、针叶林等 )和地类 (采伐迹地和宜林地等 )转型和新增的天然常绿阔叶林占现有 (1 996年 )阔叶林的 2 7.8% .由于马尾松成为首选的择伐木 ,天然阔叶林中的针叶树大量减少 ,天然阔叶林趋于纯林化 ,1 985年留存下的天然常绿阔叶林中近、成过熟林人为干扰为轻度、中度和严重的各占 1 /3左右 ,至少要禁伐 1 1～ 1 3a才可以恢复到 1 985年的森林景观水平

Studies on the Natural Evergreen Broad leaved Forest in Mingxi County Ⅰ.Area Dynamic and Type Change

Based on the data of the initial investigation and reexamination of the natural ever green broad leaved forest for forest resources checking, this paper analyzed the dynamic of the natural ever green broad leaved forest during 11 years. The results showed that the change rate of the natural ever green broad leaved forest from 1985 was reached 37 4 percent during 11 years which mean it was 4.2 percent per year; that the numbers of other forest types (plantation, needle leaved, et al ) and land use types (cutover, land suitable for planting, et al.) having been changed their type and the added natural ever green broad leaved forest accounted for 27 8 percent of the broad leaved forests in 1996. Because pinus massoniana tree become the first tree for selective cutting, the needle tree in the natural evergreen broad leaved forest deduced fast and the natural evergreen broad leaved forest tended to become pure broad leaved forest. The forests disturbed by light, middle and serious degree were almost equally in young, middle, mature and over mature forests kept from 1985, we must spent at least 11~13 years to renew the forest landscape level in 1985 by forbidding cutting.