天宝岩自然保护区森林景观格局与环境关系的尺度效应分析

Scale Effect of Relationship Between Forest Landscape Pattern and Environmental Factors in the Tianbaoyan Nature Reserve,China

为揭示景观格局内演机制,在3S技术平台支撑下,借助TM遥感像图、植被分类图和二类调查数据,并引入CCA(Canonical Correspondence Analysis)排序方法,对天宝岩森林景观格局与环境的关系及其尺度效应进行定量分析.结果表明:随着取样尺度的递减,排序轴各特征值之和呈增大趋势,依次为:3.137、3.349、3.484、4.660及4.848;而累积景观–环境解释量和景观–环境相关系数皆呈先增后减的趋势,分别在scale3和scale2达到最大;景观类型分布呈现较为明显的纬度梯度变化规律(纬度与第一轴的相关系数:-0.2019^-0.3789)和垂直分布规律(海拔与第一轴的相关系数:-0.3218^-0.4760),其中沿纬度梯度上分布的景观类型依次为:竹林、落叶阔叶林、针阔混交林、农田、常绿阔叶林、山顶矮曲林、常绿针叶林、泥潭藓沼泽、灌草丛;在较低海拔上分布的景观类型主要有竹林和农田,在较高海拔上分布着泥潭藓沼泽、灌草丛和山顶矮曲林;景观格局与环境关系具有尺度效应,环境因子对景观格局分布的影响程度随着尺度的变化而变化.

Analyzing on the relationship between environmental elements and landscape pattern contributes to the changing mechanism of landscape pattern.Based on TM image,topographic map and the second class investigation,and by means of 3S technology,the relationships between forest landscape pattern and environment factors were analyzed quantitatively with CCA（Canonical Correspondence Analysis） in the Tianbaoyan National Natural Reserve,China.The results showed that the total Eigen value of ordination axes were 3.137,3.349,3.484,4.660 and 4.848,respectively,increasing with the downscaling.However,both the cumulative percentage variance of landscape-environment relation and landscape-environment correlation coefficients first increased and then decreased,with the maximum values at scale3 and scale2,respectively.The landscape presented an obvious latitude variation（the correlation coefficients between latitude and first axis were-0.2019^-0.3789） and vertical distribution regularity（the correlation coefficients between elevation and first axis were-0.3218^-0.4760）.The latitudinal gradient distribution regularity was as follows： bamboo grove,deciduous broad leaved forest,mixed broadleaf-conifer forest,farmland,evergreen broadleaf forest,mountaintop elfin forest,evergreen coniferous forest,sphagnum moss,shrub-meadow.Bamboo grove and farmland distributed at low elevation comparing with sphagnum moss,shrub-meadow and mountaintop elfin forest at high elevation.It is suggested that the relationship between landscape and environment have scale effect,and the environmental elements have different impacts on landscape pattern at different scales.Fig 2,Tab 2,Ref 36