Flora Study of Riparian Plants on the Mountain River Banks of the Jiulongjiang River Headstream

Based on field investigation,sample collection,and comprehensive analysis of the riparian vegetation in mountain rivers,the riparian flora characteristics were investigated.The results showed that 574vascular plants belonging to 390genera and 145families in the mountain rivers of the Jiulongjiang River headstream were identified,among which pteridophyte had 29families,54genera and 80species;gymnosperm had 6families,8genera and 10species;and,angiosperm had110families,328 genera and 484 species.Through comprehensive analysis several typical characteristics of the mountain river riparian vegetation(taking reaches of the Jiulongjiang River headstream as an example)were found as follows:(1)a rich floral composition,with the dominant families and genera highly prominent;monotypic,oligotypic and oligotaxic genera,and oligotypic and oligotaxic families formed a large proportion;(2)flora of ancient origin;rare and relict plants were abundant;and,(3)complicated geographical elements and flora connected extensively with most parts of the world fully reflected natural and human disturbance such as regional climate,topography and human activities.Results indicated that the riparian zone had an extremely important function in conserving regional biodiversity.