【陆地生物圈碳输出】Galy V (Galy Valier)^{[ 1 ]} ; Peucker-Ehrenbrink B (Peucker-Ehrenbrink Bernhard)^{[ 1 ]} ; Eglinton T (Eglinton Timothy)^{[ 12 ]}. Global carbon export from the terrestrial biosphere controlled by erosion. Nature 521(7551): 204

Abstract

Riverine export of particulate organic carbon (POC) to the ocean affects the atmospheric carbon inventory over a broad range of timescales(1-5). On geological timescales the balance between sequestration of POC from the terrestrial biosphere and oxidation of rock-derived (petrogenic) organic carbon sets the magnitude of the atmospheric carbon and oxygen reservoirs(67). Over shorter timescales variations in the rate of exchange between carbon reservoirs such as soils and marine sediments also modulate atmospheric carbon dioxide levels(1). The respective fluxes of biospheric and petrogenic organic carbon are poorly constrained however and mechanisms controlling POC export have remained elusive limiting our ability to predict POC fluxes quantitatively as a result of climatic or tectonic changes. Here we estimate biospheric and petrogenic POC fluxes for a suite of river systems representative of the natural variability in catchment properties. We show that export yields of both biospheric and petrogenic POC are positively related to the yield of suspended sediment revealing that POC export is mostly controlled