腾冲县天然林景观格局垂直梯度分析

基于腾冲县1∶50 000数字化地形图和森林资源二类调查小班图层,利用Arcmap 10.0处理矢量数据、Fragstats 4.1计算景观格局指数、Excel进行数据统计和图表制作,将腾冲县天然林景观分为29个海拔带,选择景观面积、类型面积、面积比例和斑块丰富度4个景观格局指数对天然林景观的垂直梯度变化进行了分析。结果表明:景观面积随海拔梯度先增大后减小,中等海拔梯度天然林面积大,低海拔和高海拔梯度天然林面积小;不同海拔梯度天然林的主要森林类型不同,海拔2 900m以下和3 300 m以上变化较缓和,2 901~3 300 m范围内变化较剧烈;不同海拔梯度的优势森林类型不同,海拔1 400 m以下是云南松林,1 401~3 100 m是栎类林,3 101 m以上是竹林;不同森林类型的适宜分布海拔梯度不同;中等海拔梯度分布的森林类型较多,低海拔和高海拔分布的森林类型较少;海拔2 300 m以下的天然林受人为干扰比较严重。

Vertical Gradient Analysis on Natural Forest Landscape Pattern in Tengchong County

Based on the 1： 50 000 digital topographic map of Tengchong County and the sub-compartment coverage of second class investigation on forest resource,using Arcmap processing vector data,Fragstats computing landscape indices,Excel statistical data and charts,the natural landscape of Tengchong County is divided into 29 elevation belts,select the four landscape indices of landscape area,the type of area,area ratio and plaque richness for vertical gradient natural landscape analysis. The results showed that： landscape area increases first and then decreases with elevation gradient increases,middleelevation gradient natural forest area is large,while low-altitude and high-altitude gradient natural forest area are small; major forest types of natural forests at different altitudes are different. It changes moderate at altitude 2900 m or less and 3300 m above but more intense within 2901 ～ 3300m range. The advantage forest types of different altitudes are different. Yunnan pine is below elevation of 1400m,oak forest is between elevation 1401 ～ 3100m,and bamboo above 3101m. The appropriate distribution altitude gradients of different types of forest are different. Forest types distribute with moderate elevation gradient are more than at low-elevation and high altitude. The natural forest at altitude less than 2300m is affected more seriously by human disturbance.