The impact of land use on riparian soil dissolved organic matter and on streamwater quality on Chongming Island, China

• Published in: Regional environmental change Vol. 16; no. 8; pp. 2399 - 2408
• Main Authors: Yang, Changming, Wang, Yulai, Jing, Yachao, Li, Jianhua
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2016; Springer; Springer Nature B.V
• Subjects: Agricultural land; Analysis; Aquatic environment; Aquatic resources; Carbonyl compounds; Climate Change; Climate Change/Climate Change Impacts; Creeks & streams; Dissolved organic matter; Earth and Environmental Science; Environment; Environmental impact; Fatty acids; Geography; Geomorphology; Land use; Lipids; Microbial degradation; Nature Conservation; Oceanography; Organic farming; Original Article; Regional/Spatial Science; Riparian ecology; Riparian land; Soil organic matter; Surface water; Trophic status; Water quality; Wetlands; China; China, People's Rep; Water-extracted soil organic matter (WSOM); Fluvial trophic status; LC–Q–TOF–MS; Excitation–emission matrix (EEM); Riparian wetland; Land uses
• ISSN: 1436-3798; 1436-378X
• DOI: 10.1007/s10113-016-0971-x

Riparian wetland controls the transfer of terrestrial dissolved organic matter (DOM) to surface water bodies. However, the effects of land use on riparian soil DOM quality and its contribution to aquatic environment are largely unknown. In this study, the amount and composition of water-extracted soil organic matter (WSOM) in riparian wetlands were determined to evaluate the effect of land uses on spatial patterns of WSOM and streamwater quality on Chongming Island, China. The fluorescent properties of WSOM and fluvial DOM were analyzed using EEM spectra-combining PARAFAC model and accurate MS and MS/MS identification. Our findings showed no differences in the riparian WSOC contents between land use types (agricultural land, natural wetland, commercial land and industrial land). However, the fluorescent WSOM and its humic-like (Comp.1 and Comp.2) and microbial degradation (Comp.4) components significantly varied under different land uses ( P  < 0.05). Overall, the fluorescent WSOM quantities and its components (Comp.1, Comp.2 and Comp.4) were present at markedly lower concentrations for agricultural land use relative to the other three land uses. The same distribution pattern was observed for carbonyl compounds and fatty acids in the riparian WSOM molecules ( P  < 0.05), but the distribution patterns of the lipids were different between the four land uses ( P  < 0.05). Industrial land could result in the input of more organic matter into the riparian wetland. Our results showed that fluvial Comp.1 and Comp.2 were significantly correlated with WSOM Comp.2 and WSOM Comp.4 ( P  < 0.05). We also observed that the fluvial trophic status was significantly higher when the fluvial DOM components increased ( P  < 0.05). These results indicated that land uses can alter the composition of riparian WSOM, reshape fluvial DOM compositions and significantly affect fluvial water quality.