Changes of Diversity Gradient of Woody Plants Populations in Urban Riparian Forests of Beijing

【Objective】 【objective 】This paper aims to study the diversity of urban riparian forests in Beijing and explore the regularity of gradient changes in the diversity of plant populations in order to provide a basis for the construction of close-to-nature riparian plant community.【Method】Urban rivers of different scales within the sixth ring road of Beijing were divided into 337 river segments through field investigation. 575 transects in size of 400 m2 were set up to investigate the species names and quantity of arbors and shrubs. Statistical analyses were carried out to compare the changes of diversity of urban riparian forests among different ring roads,different scales of rivers and different hardeningdegree river banks.【Result】there are 119 species,75 genera,40 families of urban riparian forest in Beijing,including 82 species,49 genera,31 families of arbors and 37 species,28 genera,14 families of shrubs; the Margelf index of urban riparian arbors was ranked as 5 th-6 th ring road > 2 nd-3 rd ring road >with