塔吉克斯坦种子植物区系分析

Seed plant flora of Tajikistan

塔吉克斯坦区系位置特殊、物种独特丰富,研究其植物区系特点对于进一步全面了解中亚植物资源现状、起源及演化具有重要意义。通过文献搜集、野外调查和标本查阅,对塔吉克斯坦种子植物区系特点进行了分析。结果表明:塔吉克斯坦境内共有种子植物4 115种,隶属于110科864属,种子植物丰富、种类分布表现出多数种集中于少数科属中,同时单种及寡种科属多的两端分布的特点;植物区系主要表现为温带性质,但也受到热带植物区系的深远影响,区系成分复杂、过渡特征明显,特有属少。特有成分在种级水平上分化明显,种子植物区系性质表现出与所处自然地理条件的一致性。

Tajikistan is an inland country located in Central Asia with special flora position, unique and abundant species. Study on characteristics of this flora has important significance for further comprehensive understanding the status, origin and evolution of plant resources in Central Asia. Through the literature collecting, field investigation, specimen examination, the seed plant flora characteristics in Tajikistan was systematically analyzed. The results showed as follows： （1）The wild seed plants in Tajikistan have the characteristics of high richness and uniqueness, there are totally 4 115 species of the wild seed plants belonging to 864 genera in 110 families, including 770 endem- ic species. （2）There are 13 large families with more than 100 species, which only accounts for 11.82% of total num- ber of families, but accounts for more than 70% of the total number of seed plants. These families play dominant role in the flora of Tajikistan. On the other hand, emergencey of nearly 50% single-species and oligo-specific families indicates that environment condition in Tajikistan is quite vulnerable also. For the composition of genera, single-species and oligo-specific genera is also abundant here, which is one of the main reasons of constituting the di- versified flora in Tajikistan. （3）The seed plant flora has wide connection in geographical relationship on both family level and genus level. The flora is composed of temperate elements and tropical elements. Comparing with tropical elements, temperate elements take up absolute predominance in Tajikistan. There are 33 temperate families, occupy- ing 55.93% of the total number of families （excluding the Cosmopolitan families）, and 712 genera, occupying 91.05% of the total number of genera （excluding the Cosmopolitan genera）, which suggests that this flora is charac- terized with obvious temperate features. The tropical components occupy a relatively high proportion on the family level, indicating the connection with the tropical flora. And it also suggests that the tropical components bring an ex- tensive but weak influence on the flora of Tajikistan. The modern complicated mountain topography and low-lying river valley may create or provide the natural refuge for the thermophile plants. As a result, this flora is temperate in nature with wide connection with tropical components. Species is abundant and mixed with cold-resistant and ther- mophile plants. （4）There is no endemic family in this flora and only 6 endemic genes which accounted for 0.77% of the total genera （excluding the Cosmopolitan genus）, but the endemic phenomenon is obvious on species level, con- firming that this flora is young with the characteristics of distinct and continuous evolution.