人类活动影响下喀斯特区域景观格局梯度分析

在ARCGIS和景观结构分析软件FRAGSTATS 3.3的支持下，分析了喀斯特区域广西环江县不同人类活动强度样带1988年和2005年2个时期的景观格局变化特征，以及2005年研究区4种主要景观类型的格局特征随人类活动强度的梯度变化规律。研究结果表明，环江县景观分布不均匀，林地是研究区的基质景观类型；在景观水平上，随着人类活动强度的降低，样带景观的破碎化程度降低，形状复杂程度升高，景观斑块的分布趋于集中；在景观类型水平上，研究区4种主要的景观类型在梯度带中能够很好的反映出格局的变化特征，其中，各景观类型的面积比重、破碎度和分维数随人类活动强度的梯度变化趋势较为明显，聚集度和连通性的梯度变化幅度相对较小。研究揭示了景观格局沿人类活动强度的梯度变化规律，可为研究区自然资源的合理开发及可持续发展提供参考。

GRADIENT ANALYSIS OF LANDSCAPE PATTERN IN KARST AREA UNDER EFFECTS OF ANTHROPOGENIC ACTIVITIES

With the support of ARCGIS and landscape pattern analysis software FRACSTATS 3.3,the landscape spatial patterns of the karst areas experiencing different intensity of anthropogenic activities in Huanjiang of Guangxi Province were analyzed on the landscape level and the class level.The results showed that landscape types of Huanjiang County presented unevenness tendencies,and forest was the landscape matrix.Gradient analysis with the landscape-level index showed that,with the decrease of anthropogenic activity,the landscape in anthropogenic activity zone was becoming less fragmented,landscape shape was becoming more complicated,and landscape aggregation degree was becoming higher.Gradient analysis with the class-level index showed that,the landscape spatial patterns of the main landscape types in the study area could reflect the gradient variation well,especially the percentage of landscape,fractal dimension index and fragmentation index,whereas the gradient difference of aggregation index and connectivity index were relatively low.Gradient variations in landscape pattern along anthropogenic activities were clearly presented,and this would be useful to supply fine ground and knowledge for exploiting resources reasonably and establishing sustainable development plan in the study area.