title: [River continuum characteristics of Xiangxi River].
abstract: The density of epilithic algae and concentration of chlorophyll a, Shannon-Wiener index and primary productivity were chosen to study the river continuum characteristics of Xiangxi River. The results showed that in general, the algal density, chlorophyll a concentration and Shannon-Wiener index tended to be increased with increasing stream order, but this trend was not very evident in the first three orders and even reversed. The primary productivity was also higher in the higher than that in the lower stream orders, and reached the maximum in the fourth order, then decreased slightly. The ratio of gross primary productivity to community respiration was the highest in the first stream orders, which means autochthonous productivity was dominant in the river. The results did not absolutely tally with the RCC forecast, therefore, we can conclude that Xiangxi River had been undergone anthropogenic influence.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. tangtao@ihb.ac.cn
authors.forename: Tao
authors.initials: T
authors.lastname: Tang
authors.forename: Daofeng
authors.initials: D
authors.lastname: Li
authors.forename: Wenbin
authors.initials: W
authors.lastname: Pan
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Qu
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Cai
mesh_terms: D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017753:Ecosystem; D056890:Eukaryota / Q000254:growth & development*; D045483:Rivers
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A