![]() Integrated with hydrological information, the results demonstrated that the density current exerts a significant influence on DOM dynamics. In particular, there was more terrestrial derived and biologically recalcitrant DOM in the river mouth than tributaries in the front area, while the opposite variation was observed in the non-front area. ![]() We found that the variation of DOM composition and property between tributary and river mouth sites show different patterns between front and non-front areas of TGR. Optical techniques and ultrahigh-resolution mass spectrometry were used to comprehensively explore the variation of DOM chemistry across TGR in the water-level declining period, and biological incubation experiments were conducted to trace its biogeochemical influences. Here, we investigated four tributaries across different segments (e.g., the front and non-front areas) of the world’s largest Three Gorges Reservoir (TGR). Although dissolved organic matter (DOM) is noted to involve in biogeochemical processes, the variation mechanism of DOM chemistry across a large-scale reservoir is not well assessed. Large-scale reservoirs exhibit complex hydrological conditions and exert a significant alteration on river flowing. Our research emphasizes the necessity of incorporating the effects of EM into studies of reservoir DOC removal and CO2 emissions. ![]() The modified CO2 flux was 0.75 Tg C/year, and respired DOC accounted for about 45% of total emitted CO2 from the 15 larger reservoirs. The accumulated efficiencies were estimated to be 13% for the selected 15 reservoirs throughout the Changjiang River network, corresponding to about 0.34 Tg C/year of the respired DOC. The contribution of respired DOC to daily CO2 emissions ranged from 17 to 61%. The values for DOC turnover velocity ranged from 0.10 to 1.59 m/day, and the average DOC turnover rate was 0.13 day⁻¹, with the average removal efficiency of 12%. Our study showed the nocturnal CO2 emission rate was about twice as high as in daytime, and was strongly driven by EM. Here, in-situ diurnal and monthly observations were conducted to measure EM (including gross primary production (GPP), ecosystem respiration (ER) and heterotrophic respiration (HR)), DOC turnover and CO2 emissions in a headwater catchment reservoir in Southeastern China in 2020. However, the effects of ecosystem metabolism (EM) on DOC cycling are not well known. Please accept the terms and conditions for use of the Part B News web site.Dam reservoirs in headwater catchments, as critical zones for their proximity to terrestrial sources, play important roles in dissolved organic carbon (DOC) cycling. You may not use any trademark displayed on the site without the written permission of DecisionHealth or its respective owners. The trademarks, service marks and logos of DecisionHealth, its product-specific brands, or others used on this are the property of DecisionHealth or its respective owners. Use of this web site evidences agreement with these restrictions. This does not convey permission for commercial use or for making multiple copies for uses internal or external. Users are granted the right to print out any article and/or newsletter found on the site for individual, personal use. Do not duplicate or redistribute in any form. DOCSINK LOGIN FULLTherefore, the user assumes full liability for use of the information on this site, and understands and agrees that DecisionHealth is neither responsible nor liable for any claim, loss, or damage resulting from its use.Ĭopyright ©2010 DecisionHealth. While we strive to ensure that the information is accurate, we make no representation of its accuracy, completeness or appropriateness for a particular purpose. Part B News is a service of DecisionHealth. Enterprise wide licenses also are available. ![]() Multiple subscriptions can be purchased for one or many locations by calling an account representative at 1-80. Subscribers to Part B News are purchasing access to an online service for a defined subscription period.Įach subscription is for one user. ![]()
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