我国森林生态类型国家级自然保护区景观格局变化趋势

我国森林生态类型国家级自然保护区在各类国家级自然保护区中占据主导地位,研究该类型国家级自然保护区景观格局变化趋势对于了解我国国家级自然保护区整体景观格局及森林资源的动态变化过程,合理设置国家级自然保护区具有重要意义.通过资料查阅与数据收集,运用Arcgis 9.3软件和Fragstats 3.3景观软件计算出不同年份新建森林生态国家级自然保护区的周长及多项景观指数,并研究这些景观指数的变化趋势;采用方差分析和相关分析方法分析不同年份和不同地区森林生态类型国家级自然保护区的面积、周长的特征差异及其与保护区物种数量等的关系.结果显示:斑块密度由3.366×10-3个/km2下降到1.337×10-3个/km2,边界密度由0.151km/hm2下降到0.028km/hm2,平均斑块分维数总体上均呈先增后减的趋势,表明我国森林生态国家级自然保护区整体景观形状呈现规则化、简单化趋势,景观格局逐渐稳定化、均匀化,景观异质程度和多样性水平呈下降趋势.方差分析表明不同年份建立的森林生态类型国家级自然保护区的面积及周长都不存在显著差异;相关分析表明不同地区保护区面积及周长均与物种数无显著相关性.该研究结果可为我国国家级自然保护区建设和合理设置提供一定的参考意见.

The changing trend of landscape patterns of forest ecosystem national nature reserves in China

Forest ecosystem national nature reserves（FENNRs） have occupied a dominant position in all types of national nature reserves .To study the change trend of landscape patterns in FENNRs is of great significance for us to understand the w hole landscape pattern of national nature reserves and the dynamic changing process of forest resources in China . It can also guide a reasonable regionalization on nature reserves .We calculated and analysed perimeters and some landscape indices of newly-built national nature reserves based on collected data by utilizing software Arcgis 9 .3 and Fragstats 3 .3 .Area ,perimeter and species number of FENNR in different years and regions was compared by analysis of variance and correlation .Density of patch（PD） reduced from 3 .366 × 10^-3 ind/km2 to 1 .337 × 10^ -3 ind/km2 and density of edge（ED） varied from 0 .015 km/hm2 to be 0 .028 km/hm2 .Mean patch fractal dimension（MPFD） had a tendency of initially increasing and then decreasing . Results showed that patch shapes of national nature reserves in China gradually simplified and regularized ,landscape pattern stabilized and homogenized ,and the degree of landscape heterogeneity and diversity level declined .Variance analysis showed there was no obvious difference between areas and perimeters of newly-built FENNRs in various years .Correlation analysis showed that areas and perimeters of reserves were not significantly correlated with species numbers in different regions .This information could be used as a reference for constructing and managing national nature reserves in the future .