Geographical Pattern Of Species Diversity Of Pedicularis In Sichuan And Chongqing And Its Relationship With Main Environmental Factors

Pedicularis is the largest genus in Scrophulariaceae and also one of the largest genera of the angiosperms. It is an important element in subalpine and alpine flora of Sichuan and Chongqing. Worldwide around 600 species are recognized in Pedicularis, with majority distributed in arctic, alpine and subalpine areas in the Northern Hemisphere, adapted to cold, moist climate and alpine environment. Up to date 375 species are recognized in China, of which 181 species in Sichuan and Chongqing. Some species of Pedicularis have been used in Tibetan medicine and some have aesthetic potentials. Pedicularis is extremely diverse in corolla morphology and has attracted attention from scientists in many fields including pollination and co-evolution fields..Sichuan Province and Chongqing Municipality lie in southwestern China, with a highly diverse biophysical conditions. Rich environmental niches in the region provide base for specieation of Pedicularis. The distribution pattern of species diversity of Pedicularis, including both geographical and altitudinal distribution pattern, and its relationship with main environmental factors are dealt with in the present thesis. Though there are a lot of investigations about diversity of Pedicularis in Sichuan and Chongqing in the past, the relationship between geographical pattern of species diversity of Pedicularis and main environmental factors is hardly addressed. With use of GIS, biographic statistics and SPSS, spatial quantitative analysis, correlation analysis and cluster analysis, relationship between main environmental factors in 148 counties in Sichuan and Chongqing and geographicalspecies diversity pattern of Pedicularis is analysed in order to find out the principal factors which influence the present pattern of species diversity of Pedicularis. The main conclusions drawn are as follows:1. Higher species diversity of Pedicularis is found in western Sichuan than eastern Sichuan. Such counties as Kangding, Muli, Yajiang in Hengduan Mountain seem to be distribution and diversity center of the genus.2. Species richness of Bumbus, altitude and ^15*C accumulated temperature are the most important factors which influence species diversity of Pedicularis. Bumbus is essential for propagation of Pedicularis; ^15*C accumulated temperature has significant effect on species richness of Pedicularis and it has negative correlation with species richness of Pedicularis, which implies that Pedicularis might not grow normally in the environment with long warm duration, which is also supported by the flourishing of Pedicularis in cold environment in alpine and subalpine areas.3. The human activity and global warming will have important impact on the distribution pattern of Pedicularis.