JpGU-AGU Joint Meeting 2017

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[JJ] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS19] [JJ] Biogeochemistry

Wed. May 24, 2017 9:00 AM - 10:30 AM 302 (International Conference Hall 3F)

convener:Muneoki Yoh(Tokyo University of Agriculture and Technology), Hideaki Shibata(Field Science Center fot Northern Biosphere, Hokkaido University), Naohiko Ohkouchi(Japan Agency for Marine-Earth Science and Technology), Youhei Yamashita(Faculty of Environmental Earth Science, Hokkaido University), Chairperson:Yohei Yamashita(Faculty of Environmental Earth Science, Hokkaido University), Chairperson:Naohiko Ohkouchi(Japan Agency for Marine-Earth Science and Technology), Chairperson:Tomoya Iwata(Faculty of Life and Environmental Sciences, University of Yamanashi)

10:00 AM - 10:15 AM

[MIS19-05] High concentrations of phosphate in streams of hilly areas, which stimulate high primary production by benthic algae on pond soils

*Komei Sasa1, Ritsuka Takei, Yoh Muneoki2 (1.The University of Tokyo, 2.Tokyo University of Agriculture and Technology)

Keywords:phosphate, hilly area, primary production, river, reduction

Phosphate is an essential mineral nutrient for all life forms. However, little phosphate is present in river waters, because it is strongly adsorbed on particulates such as oxides and hydroxides of iron and aluminum. Wakamatsu et al. (2006) reported low concentrations of phosphate in many headwater streams in Japan, which was presumed to vary depending on geological features. Here, we report high concentrations of phosphate in streams of hilly areas, which are created through a topographical feature of hilly areas. The reduction of Fe under humid soils resulted in the release of phosphate, which could act as a prime source of phosphate in a watershed. Moreover, we report an occurrence of significant primary production by benthic algae on sediments of a shallow pond, which may be stimulated by phosphate released from sediments.