基于景观镶嵌模型的景观格局变化及森林破碎化分析——以南京市紫金山风景区为例  

Assessing Changes in Landscape Patterns and Forest Fragmentation Based on Landscape Mosaic Model——A Case Study from the Purple Mountains of Nanjing

作　　者：李金臣[1] 刘云峰[1] 李明诗[1] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037

出　　处：《西北林学院学报》2014年第2期226-231,共6页Journal of Northwest Forestry University

基　　金：国家自然科学基金项目(71003006);中央高校基本科研业务费专项资金项目(RW2013-06)

摘　　要：以高空间分辨率的Quickbird和Ikonos影像为数据源,利用非监督分类算法ISODATA建立研究区土地利用数据集,借助景观镶嵌模型,在5×5窗口分析尺度下提取自然类、农业类和城市类土地覆盖类型在移动窗口中所占比例,并据此将窗口中心像元划分为19种的景观镶嵌类型中的一种,从而建立研究区内的景观镶嵌图,来分析紫金山风景区2006—2010年间土地利用景观格局的空间变化以及土地覆盖类型的转移情况;同时结合边缘密度指数、最大斑块面积指数和聚集度指数分析森林破碎化趋势。研究表明:紫金山风景区以阔叶景观为基质,针叶林、建设用地景观相对为主体,其他景观呈补丁状散布其中的主体景观格局;针叶林破碎化严重,阔叶林的聚集度增加。人为旅游干扰及森林病虫害是影响该风景区景观格局变化的主要因素,相关职能部门在加大保护力度的同时,要加强土地开发利用的合理性和科学性,以实现该风景区土地及其景观资源的可持续发展。The unsupervised classification algorithm ISODATA was first applied to Quickbird （2006） and Ikonos （2010） imagery to develop land use data sets for the study site of the Purple Mountains over Nan- jing. Then a landscape composition indicator called＇landscape mosaic＇ as a framework was implemented to classify a land parcel of the established land use data into one of the 19 possible landscape mosaic classes according to the proportions of natural, developed, and agriculture land-cover types within a fixed 5 by 5 pixels window size, to create landscape mosaic maps with spatially explicit implications. Besides, land- scape metrics including edge density index, largest patch index and aggregation index were calculated to characterize the spatial patterns of land use change and the landscape fragmentation trends from 2006 to 2010. The results showed that broadleaf forests dominated the study site compared to coniferous forests and built-up types, and other remaining landscape types disperse like patches in the region. The fragmenta- tion of coniferous forest was serious, and the aggregation of broadleaf forests increased. Anthropogenic disturbances, such forest-dependent tourism and improper land use practices were the triggers responsible for the changes in the spatio-temporal patterns of the landscapes. The responsible agencies or authorities should not only enhance their conservation efforts, but also strengthen the rational utilization of land re- sources,to push the urban forests to head to a status of sustainable forest management.

关 键 词：高分辨率 景观镶嵌模型 景观格局 紫金山风景区 

分 类 号：S731.2[农业科学—林学]