Investigation And Evaluation Of Vascular Plant Resources In The Lhasa River Basin, Tibet

The investigation of vascular plant resources is carried out in the Lhasa River Basin, Tibet, China by using the route survey method combined with choosing typical habitat survey method, in the period of July to October for five consecutive years since 2010. And we found a total of 859 species, belonging to 97 families, 377 genera of vascular plants. 731 species of vascular plants recorded in the literature, compared with the record 128 species more new recorded, including 9 families of ferns, 14 genera, 21 species; 3 families of gymnosperm, 6 genera, 7; 85 families of angiosperm, 357 genera, 831 species. There are 19 species and 2 genera for the new records of Tibet during the investigation. There are 38 species of vascular plant shows as alien species in the river basin, belonging to 18 families, 31 genera. All of them are herbaceous, among which 29 species consider as invasive species in China, and canadensis Erigeron ranks as top with the biggest populations in the river basin. Except for exotic species and cultivated species, there are 743 species of seed plant in Lhasa River Basin, belonging to 78 families and 309 genera. In the flora of Lhasa River Basin, there are no endemic families in China, and the temperate distribution types are the main ones, accounting for 63.64%, and the tropical zone type is 36.36%. In the temperate zone, it takes the north temperate zone as the largest proportion, and accounts for 45.45%, and the tropical distribution is dominated by broad tropical distribution. The types of genus’ s distribution is mainly the temperate distributed, accounting for 75.69%, and in which the largest proportion is the north temperate distribution accounts for 31.76%; the tropic distribution genera are 11.76%; and Mediterranean distribution genera accounts for 8.63%. The results of family analysis are consistent with the level of the genus, and it is also dominated by the temperate distribution, and the tropical type is second, while the north temperate distribution is the largest proportion of the temperate distribution. families and genera of seed plant in Lhasa River Basin with more components of tropical distribution is due to the ancient Mediterranean flora is an important source of today’s Tibet Plateau flora, Tibet Plateau has its origin in Tethys with tropical and subtropical climate. The plants being a Tibetan herb using the three books as the standard, namely Jingzhubencao, Zangyaozhi and Honghuazangbencao, 296 species of vascular plants to be Tibetan herb were recorded in the Lhasa River Basin, belonging to 66 families and 183 genera. In addition, 3 wild thaliana Arabidopsis populations were found in the survey.