中文摘要：

修建大坝形成水库蓄水是造成景观破碎化的原因和形式之一。本研究选取了浙江千岛湖库区景观破碎化的典型区域小金山林场，调查了74个大小不一的岛屿，研究了面积对植物物种分布的影响，并比较了使物种多样性最大化的几种植物物种保护方案：小岛组合、中岛组合、大岛组合、大中小组合岛。调查共记录到乔木物种56种，灌木物种79种。将岛屿按照面积由大到小排序，将相对应分布的乔木、灌木绘制成植物物种分布表。结果显示：乔木中分布不受面积影响的物种有15种，受面积影响的有11种，介于两者之间的有30种；灌木物种中不受面积影响的有24种，受面积影响的有16种，介于两者之间的有39种。将乔木、灌木和总物种数分别累加，同时将相对应的岛屿面积按不同组合累加，绘制累加物种和面积关系图，发现在特定的相同累加面积下，组合岛的累加乔木、灌木、总物种数最多．小岛组合次之，大岛组合最少。因此，建立相同面积的保护区时，组合岛有利于保护更多的物种。

英文摘要：

Numerous human activities have resulted in landscape fragmentation, and dam construction is one of them that often leads to drastic changes in biodiversity and ecosystem functioning on local and regional scales. In this study, we investigated how island area size affected the distribution of plant species in the Thousand Island Lake region. Also, we compared several conservation scenarios for maximizing plant species diversity. We found 56 tree species and 79 shrub species in 74 islands that were surveyed. These islands and the tree and shrub species they contained were tabulated by island size and analyzed consequently. Our results showed that 11 tree species were affected by island area while 15 were not, and 30 in between being affected and unaffected. For shrubs, 24 species were unaffected, 16 were affected, and 39 species were in between being affected and unaffected to variability in island size. Comparing the cumulative numbers of tree, shrub, and all species in different scenarios of aggregating individual islands by small, medium, large, and mixed categories, respectively, we were able to examine how species richness changed with the increasing total area of habitat and which combination gave rise to the highest species richness. Our analysis revealed that, for a given total area of island habitat, mixing islands of different sizes gave rise to the highest cumulative plant species richness in terms of tree, shrub, or total species richness. The agglomeration of smaller islands resulted in the second highest species richness whereas large islands supported the lowest species richness for the same total area of habitat. Thus, our results suggest that islands of all sizes need to be considered for biodiversity conservation in the Thousand Island Lake region.