南岳衡山种子植物区系中单(寡)种属特征分析——南岳衡山植物区系研究(三)

采用查阅资料和线路调查与样地调查相结合的方法,研究南岳衡山单(寡)种属组成与特征。结果表明:南岳衡山有单(寡)种属133属,占该区域野生种子植物属的19.22%,其较大的比例反映出南岳衡山存在着有利于古老残遗植物属的保存和新建属迁移定居与分化的生态环境,单(寡)种属能表征南岳衡山区域植被的古老残遗特性,能反映植物类群的演化阶段与过程;单(寡)种属的生长型比例和生活型谱与区域种的生长型比例和生活型谱间存在着一定的差异,但均表现出以木本植物、半灌木和多年生草本占优势的生长型组成特点与高位芽>稳芽>一年生草本>地上芽(约等于地面芽)的生活型谱,说明单(寡)种属的生长型和生活型谱对植物区系组成有一定的表征作用;单(寡)种属的分布区类型能反映出南岳衡山的种子植物区系成分主要是由中国—日本分布、中国特有分布和东亚—北美间断分布为显著特征的亚热带常绿阔叶林区的植物组成特点。

Analysis on feature of single-species genera of seed plant flora in Nanyue Hengshan

Based on field and plot investigation combined with consulting relevant documents, the composition and feature of single- species genera of seed plant flora in Nanyue Hengshan were studied. The results showed that there were 133 single-species genera holding 19.22% of wild seed plant genera there, the ecological environment was beneficial to the preservation of old relict genera and the migration, settlement and differentiation of new genera in Nanyue Hengshan. The single-species genera represented the feature of old relict of vegetation and the stage and process of plant evolution. There were some difference in growth-form proportion and life-form be- twcen single-species genera and regional species, but all of which showed the compositional characteristic of growth-form that arbor was dominant and half-shrubbery and perennial herb followed, and the composition of life-form was phanerophyte 〉 crypt0phytes 〉 annual herb 〉 chamaephyte（ = hemicryptophyte）. The distribution types of single-species genera showed the feature that seed plant flora in Nanyue Hengshan was composed of sub-tropical ever-greon broad-leaved trees with intermittent Sino-Japan, Endemic in China, and East Asia and North America disjunction.