Multiple drying aspects shape dissolved organic matter composition in intermittent streams

作者：Verónica Granados, Rebeca Arias‐Real, Cayetano Gutiérrez‐Cánovas, Biel Obrador, Andrea Butturini · 发表于：The Science of The Total Environment · 年份：2022 · DOI：10.1016/j.scitotenv.2022.158376 · 被引用次数：11 · 研究领域：Marine and coastal ecosystems、Soil and Water Nutrient Dynamics、Fish Ecology and Management Studies

Water availability is a fundamental driver of biogeochemical processing in highly dynamic ecosystems such as intermittent rivers and ephemeral streams (IRES), which are recognized as the most common fluvial ecosystem globally. Because of their global extent, IRES have a remarkable contribution to organic matter processing, which is expected to intensify as climate change and water extraction expand IRES extension. Nevertheless, the effect of the complexity of the drying process on river biogeochemistry remains unclear. This study investigated how drying aspects affect the dissolved organic carbon (DOC) concentration and composition in 35 streams along a wide flow-intermittence gradient in the NE Iberian Peninsula. To do that, four drying aspects: annual drying duration, annual frequency, duration of the last drying event, and time since the last drying event were characterized. Results showed that DOC concentration and the contribution of humic-like compounds were positively associated with intensifying drying conditions. In addition, protein-like compounds decreased over the drying gradient. More specifically, changes in DOC concentration were driven mainly by annual drying duration, whereas annual drying frequency and the duration of the last drying event jointly explained dissolved organic matter composition. These results suggest that the quantity and composition of dissolved organic matter in streams respond differently to the temporal aspects of the drying process. Our ...