Spatial variability in dissolved organic matter quantity and composition in Midwest reservoirs, USA

Reservoirs are globally ubiquitous and critical for inland carbon (C) cycling, but the coupled influence of land use and hydro-climatic fluctuations on reservoir C source and composition is relatively unexplored. In this study, we used chromophoric dissolved organic matter (CDOM) absorbance and fluorescence excitation and emission matrices modeled by parallel factor analysis to characterize the source and composition of reservoir CDOM. Water samples were collected from reservoirs along a land use gradient in Missouri, USA during a wet and dry summer, respectively. Dissolved organic C (DOC) and CDOM quantity assessed by absorbance at 350 nm ( a 350 ) were significantly ( r 2 = 0.5; p