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N°i
Figure 1. Export of dissolved and particulate organic matter from the euphotic layer and sources of allochthonous
inorganic nitrogen for phytoplankton production; in the euphotic layer, relationships between new and
regenerated production, pathways of nitrogen recycling, and advection of long-lived dissolved organic
nitrogen. From Legendre and Gosselin (1989).
EXPORT PATHWAYS
Finally, variations in the pathways through which production is exported may also contribute
to uncouple the actual sequestration of biogenic carbon from the influx of allochthonous
nitrogenous nutrients. The word "export" is used here in a broader sense than generally
understood by geologists and geochemists, who usually consider only the particulate material
sinking from the euphotic layer, in other words "the amount of fallout [that the ocean]