title: Quantitative and qualitative characteristics of dissolved organic matter from eight dominant aquatic macrophytes in Lake Dianchi, China.
abstract: The aim of this research was to determine and compare the quantitative and qualitative characteristics of dissolved organic matters (DOM) from eight aquatic macrophytes in a eutrophic lake. C, H, N, and P in ground dry leaves and C, N, and P in DOM of the species were determined, and C/N, C/P, C/H, DOC/C, TDN/N, TDP/P, DOC/TDN, and DOC/TDP were calculated. Chemical structures of the DOM were characterized by the use of multiple techniques including UV-visible, FT-IR, and (13)C CP/MAS spectra. The results showed subtle differences in quantity and quality of DOM among species and life-forms. Except oriental pepper which had a C/H of 0.7, C/H of all the other species was 0.6. C/N and C/P of ground leaves was 10.5-17.3 and 79.4-225.3, respectively, which were greater in floating and submerged species than in the others. Parrot feather also had a small C/P (102.8). DOC/C, TDN/N, and TDP/P were 7.6-16.8, 5.5-22.6, and 22.9-45.6 %, respectively. Except C/N in emergent and riparian species, C/N in the other species and C/P in all the species were lower in their DOM than in the ground leaves. DOM of the macrophytes had a SUVA254 value of 0.83-1.80. The FT-IR and (13)C NMR spectra indicated that the DOM mainly contained polysaccharides and/or amino acids/proteins. Percent of carbohydrates in the DOM was 37.3-66.5 % and was highest in parrot feather (66.5 %) and crofton weed (61.5 %). DOM of water hyacinth, water lettuce, and sago pondweed may have the greatest content of proteins. Aromaticity of the DOM was from 6.9 % in water lettuce to 17.8 % in oriental pepper. DOM of the macrophytes was also different in polarity and percent of Ar-OH. Distinguished characteristics in quantity and quality of the macrophyte-derived DOM may induce unique environmental consequences in the lake systems.
authors.affiliation: Institute of Water Science, Beijing Normal University, Beijing, 100875, People's Republic of China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Qu
authors.forename: Li
authors.initials: L
authors.lastname: Xie
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.forename: Yingchen
authors.initials: Y
authors.lastname: Bai
authors.forename: Yuanrong
authors.initials: Y
authors.lastname: Zhu
authors.forename: Fazhi
authors.initials: F
authors.lastname: Xie
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
authors.forename: Fengchang
authors.initials: F
authors.lastname: Wu
mesh_terms: D002681:China; D004784:Environmental Monitoring; D005068:Eutrophication; D060106:Lakes / Q000737:chemistry*; D010944:Plants / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical