摘要
In terrestrial ecosystems,carbon(C)transportation and C pool transformation processes both occur at the landriver-estuary continuum.Moreover,C budget and C balance processes are generally critical in achieving the C neutrality of terrestrial ecosystems.This study analyzes key C transportation processes at multiple interfaces that collectively constitute the land-river-estuary continuum,discusses C transportation and sedimentation processes at the land-river interface,and reveals aquatic plant C sequestration coupling processes and associated productivity.Transformation mechanisms of inorganic-organic C pools are also investigated here as well as a systematic evaluation of C transport flux within the different interfaces that constitute the land-river-estuary continuum.Results show that the net C sink of terrestrial ecosystems was 1.70 Pg C yr^(−1),wherein the gross primary productivity(GPP)of global terrestrial vegetation reached 123 Pg C yr^(−1),while rock weathering also consumed 0.30 Pg C yr^(−1)of atmospheric carbon dioxide(CO_(2)).Subsequently,the C transported by the land-river-estuary continuum reached 1.70 Pg C yr^(−1).During this process,0.20 Pg C is deposited and buried in inland water and 1.00 Pg C escapes from inland water systems each year.Therefore,only 0.85 Pg C is transported to the estuary.Finally,this study clarifies control mechanisms of C transportation and transformation processes at the land-river-estuary continuum.The aim of this study is to provide an important scientific basis for the quantitative analysis of C sources and sinks at the land-river-estuary continuum and C neutrality of the biosphere.
基金
financially supported by the National Natural Science Foundation of China(42141015,31988102 and 41922003).
