天宝岩国家级自然保护区森林景观格局特征变化

利用3S技术,系统分析了1992—2001年间天宝岩自然保护区森林景观格局与动态。结果表明:常绿阔叶林和常绿针阔混交林为该研究区的优势景观类型,二者占总面积的75%。除常绿针阔混交林外,各森林景观类型面积均呈增加趋势,以竹林的面积增幅最大为32.94 hm2,其次是常绿阔叶林,其面积增加32.22 hm2,落叶阔叶林的面积增幅最小。泥潭藓沼泽的破碎度、分离度和斑块密度最大,分别为0.511、5.835、0.163,且呈减少的趋势,常绿阔叶林的斑块形状指数、斑块形状近圆指数和分维数值较大,分别为1.916、0.706、1.084,亦呈下降的趋势,而落叶阔叶林和泥潭藓沼泽的斑块形状指数和分维数都接近于1,且斑块形状近圆指数在0.4左右,各森林景观类型的指数变化不明显。天宝岩自然保护区总体景观多样性、均匀度有所增加,优势度有所减少,但3个指标的变化幅度都很小。

Studies on Changes of the Forest Landscape Pattern Features in Tianbaoyan National Nature Reserve

By using 3S techniques,a systematic analysis was made of the forest landscape pattern and developments between 1992 and 200 in Tianbaoyan National Nature Reserve.The results demonstrated that both evergreen broadleaf forest and evergreen conifer-broadleaf mixed wood were the superior landscape types and both of them accounted for 75% of the total area.Except for evergreen mixed wood,the areas of the other forest landscape types were increasing,with bamboo forest the highest amplitude of 32.94 hm2,evergreen broadleaf forest the increasing area of 32.22 hm2,and deciduous broad-leaf forest the lowest amplitude.Considering 3 aspects of indexes of fragmentation division degree and patch density,the sphagnum moss had the highest index values of 0.511,5.835,0.163 respectively,all of which showed a decreasing trend.Evergreen broadleaf forest had the highest indexes of patch shape index,related circumscribing circle and fractal dimension,which were 1.916,0.706,1.084 respectively and also showed a decreasing trend.However,patch shape index and fractal dimension of deciduous broad leaved forest and sphagnum moss were close to 1,and related circumscribing circle index values were about 0.4.All the forest landscape types were changing gently.The landscape diversity and evenness of the overall landscape types increased a little and the dominance decreased slightly,but the variation amplitude of 3 indexes was very small.