Zheng L.-WLi DDing XLee T.-YZheng ZShiah F.-KZheng XHsu T.-CJR-CHUAN HUANGKao S.-J.2021-07-172021-07-17202021698953https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081012893&doi=10.1029%2f2019JG005240&partnerID=40&md5=330220915d4d7ff223af900ea3e10768https://scholars.lib.ntu.edu.tw/handle/123456789/571772Reservoirs are active sites in the terrestrial environment in terms of carbon transformation and storage. Continuous reservoir construction reinforces the importance of such artificial storage; however, knowledge pertaining to the sources, cycling, and preservation of autochthonous/allochthonous particulate organic carbon (POC) in reservoirs remains incomplete. We monitored the flux and carbon isotope composition of sinking particles in a subtropical deep reservoir, and the results were compared with the isotopic signatures of potential POC sources (soil) and the sedimentary sink. We found that the typhoon-induced POC flux was transported laterally at intermediate water depths within the reservoir and that it contributed more than 70% of the annual deposition. An isotope ternary mixing model showed that over 87% of the POC preserved in sediments was allochthonous. Although the autochthonous POC from primary production was preferentially degraded, the preserved autochthonous POC (42 ± 14 gC m?2 yr?1) was comparable to the observed carbon dioxide uptake (35 gC m?2 yr?1) by the reservoir, suggesting a high efficiency of carbon preservation in subtropical deep reservoirs. ?2020. American Geophysical Union. All Rights Reserved.autochthon; carbon dioxide; carbon isotope; carbon sequestration; intermediate water; mixing; particulate organic carbon; primary production; sedimentary sequence; terrestrial environment[SDGs]SDG6[SDGs]SDG13[SDGs]SDG14journal article10.1029/2019JG0052402-s2.0-85081012893