秦岭植物区系的性质、特点和起源

秦岭是中国长江和黄河两大水系的分水岭，位于北纬32°5′至34°45′；东经104°30′至115°52′，最高峰达3767m。该山区是我国温带植物区系最丰实的地区之一，约有种子植物3124种，隶属于158科，892属。包括热带属220属，温带属563属，和中国特有属39属。根据该山区植物区系中各大科、主要植物群落优势种和组成种类的温带性质以及温带属在整个植物区系中的主导地位。该山区的植物区系和植被具有明显的温带性特点。特有种和非特有种的分析结果表明，该山区植物区系的特点还表现在高度特有性和以中国-日本森林植物区系为主体方面。 根据古植物学资料分析，秦岭地区植物区系的起源时间不会晚于晚白垩纪；植物群落的主要成份可能以原地生长的种类为主；秦岭及其邻近古老山区，不仅对自身的植物区系和植被具有较大的发生意义，而且对东亚植物区系具有始生性质。

AN ANALYSIS OF THE FLORA OF QINLING MOUNTAIN RANGE: ITS NATURE,CHARACTERISTICS,AND ORIGINS

The Qinling Mountain Range, which covers an area of ca. 76500km2 and ranges from 32 5' to 34 45' N and from 104 30' to 115 52' E, is a major watershed of the Huanghe and Chang Jiang rivers with the highest peak about 3767 m above sea level. The flora comprises ca. 3124 species in 892 genera, of which 51. 9% of species and 4. 4% of the genera are endemic to China. Evoluated in this paper is the importance of the 20 larger families which together contain 65.2% of the total number of species. The phytogeographical affinities of genera of seed plants in the flora are analyzed and briefly discussed. Among the native genera of the flora of the Qinling Mountain Range, 220 (26.8%) are tropical, 563 (68.5%) temperate, and 39 (4.7%) endemic to China. It is clear from the figures that temperate genera play an important role in the flora and vegetation of the Qinling Mountain Range. The features of the flora include the unusually high proportion of endemic species, a wealth of Sino-Japanese elements and prominant. temperate nature in compsition. On the basis of analysis of paleobotanical materials in the Qinling Mountain Range and adjacent areas, historical distribution of dominant species, and the origin and relationships of Chinese endemic genera occurring there, the flora is of outstanding originality. No doubt, the rich and diverse flora have evolved gradually and autochthonously at least since the latest Cretaceous.