Spatio-temporal Variations of Dissolved Organic Matter in a German Forested Mountainous Headwater Catchment

摘要: The dissolved organic matter (DOM) quality or quantity of stream waters reflects catchment functioning. Dissolved features, pH, and Fe content in the main tributaries forested Wustebach Germany were examined for a 4-yr weekly sampling period (2009–2013). outlet (Wu14) discharge (Q) ranged from 0.22 to 72.5 L s −1 , with minima maxima around summer winter seasons, respectively. Discharge clearly followed precipitation late autumn early spring period. C (DOC) values at Wu14 between 0.8 7.4 mg mean 2.7 . Annual periodicities DOC temperature (T), concentrations positively correlated, reflecting DOM transport via organo-mineral complexes. watershed dominated by surficial water (Wu01, Wu08, Wu09) exhibited relatively high DOC, Fe, specific UV absorbance (SUVA) variability. Groundwater-dominated (Wu03, Wu12, Wu15) had lower, less variable contents. extremely dry 2011 limited effect on chemistry. Outlet reflected seasonally contributions groundwater, annually 65 vs. 35%. Critically, lowering SUVA (reduction aromaticity increased biodegradability) was observed headwater (Wu01 Wu08) but not Wu14. Our long-term spatial-temporal explicit data set, covering both quantity, critical apportionment contributing sources drivers sub- whole-catchment dynamics.