Author(s): Yunfeng Li; Ziwei Shen; Yan Zhang; Zhaohui Ni
Linked Author(s):
Keywords: Phytoplankton; Community structure; Density; Environment factors; The Chishui River
Abstract: Being the last undammed tributary of the upper Yangtze River, the Chishui River is an important part of the protection zone. In this paper, the relation between the phytoplankton community structure and water environment factors in the Chishui River was analyzed. The data of phytoplankton and water environment factors in the research were from the field investigation in the Chishui River during the year of 2007 to 2010. The investigations were usually carried out in June (fish reproducing stage), September (fish fattening stage) and December (fish overwintering stage) of every year. The results were showed as followings: 1) Phytoplankton species community: The investigation result showed that there were five hundreds and seventeen phytoplankton species that belonged to eight phylum. The phytoplankton species of Bacillariophyta was the most and planted the class number 67. 97% . The phytoplankton species of Chlorophyta and Cyanophyta planted the class number 17. 83% and 10. 61% respectively. The phytoplankton species of Euglenophyta and Xanthophyta planted the class number 1. 98% and 1. 34% respectively. The phytoplankton species of Chrysophyta and Pyrrophyta planted the class number 0. 70% and 0. 93% respectively. The phytoplankton species of Cryptophyta planted the class number 0. 50% . 2) Phytoplankton density: The phytoplankton density was range of 4. 15×104 cells/L ‒ 99. 00×104 cells/L. The maximum value of phytoplankton density occurred at the stage of fish reproducing and fattening during the years of 2007 to 2009, which was 65. 73×104 cells/L、63. 40×104 cells/L、44. 45×104cells/L and 99. 00×104cells/L respectively. 3) Correlation between phytoplankton community structure and environment factors was analyzed by Canonical Correlation Analysis (CCA). The result showed that NO3 --N affected the phytoplankton community structure in the Chishui River more than other environment factors such as magnesium ion (Mg2+), Water hard (WH), Total nitrogen (TN), pH, --N) and calcium ion (Ca2+). 4) Correlation between Dissolved oxygen (DO), nitrite nitrogen (NO2 phytoplankton density and water environment factors were analyzed by Pearson's correlation. The result showed that the phytoplankton density was significantly correlation with the environment factors such as DO, ammonia (NH3), ammonia nitrogen (NH4 +-N) (r= 0. 55, 0. 54, 0. 56) in June. And the environment factor of total phosphorus (TP) was very significant correlation with the phytoplankton density (r = 0. 73) in June. While in September and December, the phytoplankton density was no significant correlation with the water environment factors. Based on phytoplankton community structure and relationship with the water environment factor, conservation strategies were proposed for different reaches.
Year: 2013