The Systematic Classification And Floristic Geography Of Campanulaceae In Gansu Province

The systematic classification and floristic geography of Campanulaceae in Gansu Province were studied in this thesis.All the species of Campanulaceae were recognized in Gansu province based on herbarium examinations of more than five thousand specimens from four berbmas( abbreviated as PE, WUK, QTPMB,GAUF),literatures and additional fieldwork,they had also contributed to reveal the main morphological characters and their evolution studies.Based on the materials of systematic classification and geographic distribution, the modern geographic distribution pattems(distribufion types) of all the species and genera in this region were classified and taken into statistical analysis,and were used similarity coefficient analysis to compare with adjacent regions to display the geographical distribution features,floristic elements,the relationship of floristic similarity and the floristic origin of the family Campanulaceae in Gansu. The results were summarized as follows:1. Six generas, twenty five species and 8 varieties of the family Campanulaceae were recognized in Gansu province : morphological description, localities,habitats,specimens cite were given in detail and were the systematic key to the genera and species had been made.2. Codonopsis henryi Oliver, Campanula colorata Wallich and Adenophora tetraphylla(Thunberg) Fischer, Codonopsis pilosula subsp. tangshen(Oliver) D.Y. Hong were recognized as new records in geographical distribution from Gansu Province.3. The areal-types of genera of this Campanulaceae flora could be divided into 3types. Among them,the East Asia type was the richest one,accounting for66.66% of the total genera.4. According to different areal divisions,the geographic distribution ranges of the family in Gansu were divided into 8 regions: in the the mountains area in southern Qinling,Xiaolong mountain and Huixian-Chengxian basin,the Middle-upper reaches of the upstream mountainous district Taohe-Xiahe and the mountains area in northern-middle reaches of Longxi Loess Plateau was seemed to be the center of the distribution density and the species diversity of Campanulaceae in Gansu province.5. There were higher floristic similarity of genera and species among Gansu,Shaanxi, Qinghai and Inner Mongolia.The hightest similarity was between Gansu and Shaanxi, about 92.3 %.However the similarity coefficient between Xinjiang,Inner Mongolia, Sichuan as well as Ningxia was lower.The floristic similarity of species between Gansu and Shaanxi was hightest, up to84.21%, followed by Ningxia and Qinghai, which is 56.52% and 53.06%,respectively, and the rest of the provinces are low. This shows that the similarity of Campanulaceae plants between Shaanxi and Gansu is the hightest, followed by Ningxia.6. The Campanulaceae flora in Gansu province was closely linked with Qinghai-Tibet Plateau,which is the important fringe of the northern extension of Qinghai-Tibet Plateau;the Campanulaceae flora in Gansu province was mainly to the temperate nature, which had the similar area of nature and origin with Qinghai-Tibet Plateau,it was the continuation and development of latter.