秦岭种子植物区系科的组成、特点及其地理成分研究

秦岭种子植物区系组成丰富，共有种子植物198科、1007属、3446种，区系组成的大科及主要科共16科，占秦岭种子植物总数属的50．05％，总种数的57．25％，它们构成了秦岭植物区系组成的基本框架，就其性质来讲，绝大多数为温带性质，松科、壳斗科、桦木科、杨柳科、蔷薇科、杜鹃花科、禾本科、莎草科等是秦岭植被的区系组成的优势科，从地理成分上来分析，本区科的分布型可以划分为世界或亚世界分布科、热带分布科、温带分布科、间断分布科以及东亚和中国特有科，其区系的起源则有明显的古老性。

STUDIES ON THE COMPOSITION,CHARACTERISTICS AND GEOGRAPHIC ELEMENT OF THE FAMILY OF SEED PLANT FLORA IN QINLING MT.

The composition, characteristics and geographic element of the seed plant flora in Qinling Mt. are studied in this paper. The result shows: the Qinling Mt. is rich in flora, there are 198 families, 1007 genera and 3446 species. There are 16 large and major families in this area, they make up 50.05 per cent of the total genera and 57.25 per cent of the total species, the large and major families are basic frame of the flora composition in Qinling Mt. and the quality of them mostly is temperate. The dominant families of flora composition of the vegetation are Pinaceae,Fagaceae,Betulaceae, Salicaceae,Rosaceae,Ericaceae,Gramineae and Cyperaceae. The geographic element of the family is divided world or sub-world distribution, tropical distribution, temperate distribution, discontinuous distribution , East Asia distribution and China endemic distribution. and the origin of flora is clear ancient?