湖南黄桑国家级自然保护区植被景观格局探讨

Analysis on vegetation landscape pattern of Huangsang National Nature Reserve in Hunan

①斑块特征指数分析表明:各景观类型的密度、分维数指数都较小,植被景观的深展指数都不高,扩散比较均匀,没有极端复杂的形状产生,植被景观在演替系列中还没有普遍达到演替的顶级,斑块之间自相似程度较高。②多样性指数分析表明:总体多样性程度高。景观多样性指数、优势度指数与均匀度指数的结果所包含的意义一致,这种一致性充分说明了各植被景观类型分布均匀,各景观类型地位相差较小。③空间构型指数分析表明:保护区的斑块密度为1.001,即1 km2上有1.001个斑块。这说明斑块数目较少。各景观类型分布也较均匀。保护区景观破碎度指数为0.007,这表明该区植被景观在研究期内所表现的生境破碎化程度是很低的。每一植被景观类型破碎度指数最高的是灌丛和灌草丛景观,其次为栲林景观,其余的破碎度都处于较低的水平。内部生境破碎化指数以灌丛和灌草丛景观、栲林景观为最低,它们的单独斑块面积较大,故破碎化指数较低。其它景观类型的破碎化指数相差不大,这与植被顺向演替是相关的。景观分离度指数的排序结果与斑块密度的排序基本一致。

The results of landscape pattern study show： 1 ）The results of patch characteristics indexes analysis shows： Patch density, fractal dimension and extension indexes are low in each landscape type. The patches distribute evenly and the form of the patch is not extremely complex. Vegetation landscape has not reached its top succession. Patches have high self-similarity. 2 ）The results of diversity indexes analysis shows：The whole diversity is high. Landscape diversity indexes, dominance indexes and evenness indexes revealed the same result： All vegetation landscape types distributed evenly. 3 ）Spatial pattern analysis suggests： The patch density indexes is 1.001, namely there are 1. 001 patches in I kma, which suggests the number of the patches is small. The patches distribute evenly. Landscape habitat fragmentation index is 0. 007, which shows the degree of vegetation landscape habitat fragmentation is low during the research period. As to each vegetation landscape type, the habitat fragmentation index of bushy hillside grassland landscape is the largest, and Castanopsis fargesii landscape is the second. The other landscape types are low. The interior habitat fragmentation indexes of bushy hillside grassland landscape and Castanopsis fargesii landscape are the lowest, because the two landscape types have the largest single patch area. And the other landscape types are low, which is relative to the succession of the vegetation landscape. The landscape separation indexes have the same results with the patch density indexes.