基于GIS和二类调查数据的森林资源时空动态分析与评价

以黄龙山林业局蔡家川林场为研究对象,以1986年和1997年森林资源调查数据为基础,以地理信息系统为技术支持,分析和评价了11a间该场森林资源的数量、种类及其结构在时间和空间上的动态变化。结果表明:全场天然林面积增长6.98%,有林地面积增长7.66%,疏林地减少5.48%。人工林的面积也有所增加。全场活立木蓄积量下降了6.70%,且下降的主要是天然林。林分平均每公顷蓄积、平均树高、平均胸径、平均郁闭度、平均年龄5个因子均减小。各龄组中,幼龄林和中龄林的面积和蓄积都有所增加,其中以中龄林增加幅度最大。近熟林、成熟林和过熟林的面积和蓄积有所减少,尤以近熟林和成熟林减少幅度最大。至1997年,幼、中、近、成、过各龄组的面积和蓄积比例仍不合理,以中龄林和近熟林占的比例最大,无过熟林。因此,需要采取相应的措施,调整并恢复林场的合理森林结构,实现森林资源的可持续经营。

Spatial-temporal Analysis and Evaluation of Forest Resources Based on GIS and Forest Resource Inventory Data

An experiment was conducted to analyze and evaluate the spatial-temporal dynamic changes of amount, types and structure of forest resources in Caijiachuan Forest Farm, Huanglongshan Forestry Bureau in Shanxi Province based on GIS and forest inventory data during 1986 and 1987. Results showed that natural forest area and forested area increased by 6.98% and 7.66% respectively, sparse woodland area decreased by 5.48%, and artificial forest area also increased slightly. The growing stock decreased by 6.70%, which mainly occurred in natural forest. Five average factors of stands including per-hectare volume, tree height, diameter at breast height, canopy closure and forest age all decreased. Among five age groups, the areas and volumes of young forest and middle-aged forest increased, and the increasing extent of middle-aged forest was more than that of young forest. The areas and volumes of near-mature forest, mature forest and over-mature forest decreased, and the increasing extents of near-mature forest and mature forest were more than that of over-mature forest. Up to 1997, the proportions of the five age groups were still unreasonable in terms of the highest percentage of middle-aged and near-mature forests as well as no over-mature forest in this region. Therefore, feasible management measures should be adopted so as to adjust and recover reasonable forest structure and realize sustainable forest management.