2018/10/03 by Benoît O. L. Demars · 87 citations
Chemistry · Earth and Planetary Sciences · Environmental Science · #Benthic zone #Biology #Carbon cycle #Chemistry #Dissolved organic carbon #Drainage basin #Ecology #Ecosystem #Environmental chemistry #Environmental science #Geology #Hydrology (agriculture) #Hydrology and Watershed Management Studies #Marine and coastal ecosystems #STREAMS #Soil and Water Nutrient Dynamics
paper · open access · doi:10.1002/lno.11048
published in Limnology and Oceanography 64(1), 406-421 (Wiley)
openalex publication_date 2018/10/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract Stream metabolism plays a significant role in the global carbon cycle. Storm events can lower stream metabolic activities by removing standing biomass and river bed stock of organic matter. However, hydrological events could also stimulate stream ecosystem respiration (ER) by providing dissolved organic carbon (DOC) derived from soils. Here, I show how hydrological connectivity between land and water affects fluxes of DOC and daily whole stream bacterial respiration over an annual cycle in streams rich in DOC in north‐west Europe. The novelty of the approach resides in combining continuous whole stream metabolism with hydrological flow paths and water chemistry to quantify the in situ fate of DOC at ecosystem scale, with an estimation of all major stream carbon fluxes (land‐derived CO 2 , in‐stream biotic CO 2 , HCO 3 , and DOC) at catchment scale. An average 23% ± 11% of the annual DOC inputs from the land was respired away by benthic microbial metabolism within about an hour of transit time in small watersheds (about 1 km 2 ). Stream ER was highly related to discharge and was stimulated for as long as the hydrological connectivity between land and water remained, as indicated by soil moisture continuous monitoring. In‐stream heterotrophic respiration represented 16% ± 7% of the annual total carbon fluxes (also including HCO 3 , land‐derived CO 2 , and DOC) at the catchment outlet under stable flows. This study suggests that DOC supply (soil carbon loss) will increase with rainfall, stimulating aquatic respiration, and CO 2 emissions in streams.