title: Submerged vegetation removal promotes shift of dominant phytoplankton functional groups in a eutrophic lake.
abstract: Historical data indicate that the dominance of submerged plants in Dianchi Lake in the 1960s was characterized by low algal density with dominance of non-toxic group J (Scenedesmus, Pediastrum, etc.). The removal of submerged plants, which began in the 1970s, resulted in the expansion of bloom-forming Microcystis (group M). Laboratory experiments suggested that Microcystis aeruginosa was inclined to grow and develop at elevated temperatures. The growth of Scenedesmus obliquus was slower than that of co-cultivated M. aeruginosa in the absence of Ceratophyllum demersum, especially at higher temperatures. The existence of submerged plant C. demersum could inhibit the growth of the harmful algae M. aeruginosa and this inhibitory effect by C. demersum was enhanced with an increase in temperature. Instead, with C. demersum, the growth of S. obliquus was not inhibited, but the co-cultivated M. aeruginosa was eliminated in a short time. Combined with the historical data and laboratory experiments, it was indicated that the submerged plants might play important roles in the dominance of the non-toxic group J in the historical succession. Consequently, the introduction of the submerged plant such as C. demersum might alter the dominant phytoplankton functional groups from M to J and benefit the restoration of the eutrophic lake.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China. Electronic address: happydj111@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Dong
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: ligb@ihb.ac.cn.
authors.forename: Genbao
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Song
mesh_terms: D005068:Eutrophication; D060106:Lakes; D010839:Phytoplankton / Q000502:physiology*; D010944:Plants; D013997:Time Factors
keywords: Functional groups; Phytoplankton; Submerged vegetation