城乡森林分布格局与土地利用对策

根据1988年及2003年南京市城镇边界, 利用遥感影像和DEM数据,以及缓冲区分析法,将南京地区2003年植被图由城区向远郊分成8个城乡梯度带,依次命名为Ⅰ带，Ⅱ带，Ⅲ带，……，Ⅷ带,研究了各带森林分布格局,以及地形条件和土地利用对策对森林分布格局的影响.结果表明,各带山体占地率与森林覆盖率呈极显著正相关,且各带山体森林覆盖率显著高于平地森林覆盖率,其基本格局为：Ⅰ＞Ⅱ，Ⅱ＜Ⅲ,Ⅲ≈Ⅳ,Ⅳ＞Ⅴ＞Ⅵ＞Ⅶ＞Ⅷ；在不同的城乡梯度带,城市化地区城建用地、生态用地和生产用地3种主要土地利用方式的价值输出不同.城区城建用地价值突出,林地覆盖率最低；城区外围10 km内的近郊的生态环境价值输出相对较高,林地覆盖率亦高于其它各带；离城稍远,以农业为代表的物质生产价值渐居主导地位,森林覆盖率则随之下降.

Forest distribution pattern and land use strategy along urban-rural gradient

According to the buffers and urban fringes of Nanjing in 1988 and 2003, and by using landsat TM images and DEM data, 8 urban-rural gradient zones called I, II, III,......, VIII in this city were marked off, and the forest distribution pattern as well as the land use strategies along these gradient zones were studied. The results showed that in each of these zones, there was a significant positive correlation between the coverage of mountainous area and forest, and the forest coverages were obviously higher in mountainous than in flat area, with a distribution pattern of I > II, II < III, III approximately equal to IV, IV > V > VI > VII > VIII. In urbanizing area, there were three major landuse types, i. e. , urban building, ecological regulation (mainly forest stand), and agricultural production (mainly crop land). The potential value of a certain land use type became the leading cause of land use type selection. Inner city area had very low forest coverage because of its high exploitation value, and the ecological value of the outskirts within 10 km beyond the urban fringe was comparatively outstanding, with the forest coverage increased significantly. The forest coverage declined with the increasing distance to urban, because of the dominant station of the production value.