Colloidal catchment response to snowmelt and precipitation events differs in a forested headwater catchment

• Published in: Vadose zone journal 2021-05, Vol.20 (3), p.n/a
• Main Authors: Burger, Dymphie J., Vogel, Johnny, Kooijman, Annemieke M., Bol, Roland, de Rijke, Eva, Schoorl, Jorien, Lücke, Andreas, Gottselig, Nina
• Format: Article
• Language: English
• ISSN: 1539-1663; 1539-1663
• DOI: 10.1002/vzj2.20126

Climate change affects the occurrence of high‐discharge (HD) events and associated nutrient exports in catchment stream water. Information on colloidal events‐based losses of important nutrients, such as organic C(Corg), N, P, and S, remain relatively scarce. We hypothesized that contributions of colloidal exported N, S, and P due to differing hydrological mechanisms vary between HD events in late winter and spring. We examined one combined snowmelt and rainfall event (March 2018) with one rainfall event (May 2018) for temporal Corg, N, P, and S dynamics. The catchment exports of colloids and their subset nanoparticles were analyzed by asymmetric‐flow field flow fractionation (P) and a filtration cascade (N and S). The Corg source in both events was assessed by δ13C composition of the stream water in relation to that of the soil. In winter, 0.1 μm), but this was 29–64% in spring and was associated with Corg, Fe, and Al. Colloidal N and particulate S (>1 μm) were higher during both events, but the majority of losses were dissolved (