八大公山自然保护区的野生观赏植物资源

初步查明该区具有野生观赏植物793种,分别隶属于110科,320属.对其中具有一定代表性、开发利用潜力较大的160种植物的生活型、可供观赏的主要特征、花果期及生境等,以表列的形式进行了扼要描述.最后,就如何充分、合理地开发和保护该区的野生花卉资源,作者提出了自己的看法.     

Disentangling the effects of topography and space on the distributions of dominant species in a subtropical forest

Topography and space are two important factors determining plant species assemblages in forest communities. Quantification of the contribution of these two factors in determining species distribution helps us to evaluate their relative importance in determining species assemblages. This study aims to disentangle the effect of topography and space on the distributions of 14 dominant species in a subtropical mixed forest. Spearman correlation analysis and the torus- translation test were used to test the species-habitat associa- tions. Variation partitioning was used to quantify the relative contributions of topography and space at three sampling scales and three life stages. Correlation analyses and torus-transla- tion tests showed species abundance was mostly correlated with topographic wetness index, vertical distance from the channel network and convexity. Variation partitioning showed that pure topography, pure space and spatially struc- tured topography explained about 2.1%, 41.2 % and 13.8 % of the variation in species distributions, respectively. For nine species, total topography fractions peaked in 20 m quadrats. For ten species, the pure space fractions peaked in 50 m quadrats. For many species, the total topography fraction and the pure space fraction were larger for the most abundant life stages, which reflected the importance of sampling effect. However, some cases did not follow this trend suggesting that the effects of ecological processes such as habitat filtering, density dependence or dispersal limitation may exceed the sampling effects. In conclusion, we found that spatially structured topography and pure space primarily shaped the distribution of dominant tree species. Furthermore, their effects were both scale- and life stage-dependent.     

八大公山红腹角雉对植被因素选择的分析

2002年8月至2005年7月,通过样线调查、定点监测、样方调查法对湖南八大公山国家级自然保护区内分布的红腹角雉进行了调查。 结果表明,在植被因素方面,红腹角雉偏向于在常绿落叶阔叶混交林中活动,乔木郁闭度在70%以上,对灌木盖度没有很大偏好;对于草本层,红腹角雉多选择活动在草本平均高度为11～30?cm之间,盖度 在10%～50%之间的区域。因为是地面活动型鸟类,其活动区域排除乔木郁闭度和灌木盖度因素外,其林相主要为“亮脚林”,即乔木或灌木下100?cm的空间。