9:00 AM - 9:30 AM
[ACG42-01] Nutrient dynamics along the land-to-river-to-ocean continuum and its potential impacts on coastal primary production
I will present our recent empirical studies conducted in three Japanese watersheds (Fuji River, Iwaki River, and Kanogawa River), which show that landuse development, volcanic-rock lithology and in-stream processing are major factors controlling the flux of river-borne nutrients during the base flow period. Our study also shows the functional relationship between fluvial geomorphology (e.g., channel size and river network structure) and the riverine biogeochemical flux. I emphasize that physical modifications of river network structure may affect the delivery of nutrients to coastal areas, resulting in change of the strength of land-ocean linkages. Moreover, river-borne nutrients interact with rainfall runoff events to influence the growth of coastal primary producers. On the basis of the obtained results, I present empirical and theoretical considerations on the effects of riverine solute dynamics on the coastal food webs.