日本地球惑星科学連合2015年大会

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セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS26] 生物地球化学

2015年5月27日(水) 18:15 〜 19:30 コンベンションホール (2F)

コンビーナ:*楊 宗興(東京農工大学)、柴田 英昭(北海道大学北方生物圏フィールド科学センター)、大河内 直彦(海洋研究開発機構)、山下 洋平(北海道大学 大学院地球環境科学研究院)

18:15 〜 19:30

[MIS26-P05] 野洲川における降雨時の生物利用可能懸濁態リンの流出量の測定

*千代 真照1尾坂 兼一2永淵 修2奥田 昇3 (1.滋賀県立大学大学院環境科学研究科、2.滋賀県立大学環境科学部、3.総合地球環境学研究所)

It is well known that primary production in Lake Biwa is limited by phosphorus, and that means phosphorus load into Lake Biwa influence on its environment. In general, it is considered that algae in lake use PO4-P as a phosphorus nutrient, however, it has been revealed that a part of particulate phosphorus (PP) also might be used as nutrient in recent study. However, there are a few studies that quantify the load of bioavailable PP discharged through river in Japan. The purpose of this study is to quantify the load of bioavailable PP discharged through Yasu river into Lake Biwa during rainfall events. Water samples were collected at one to six hours interval in two rainfall event (May and July) in Yasu River using automatic river water collector. We measured several forms of PP by sequential extraction methods (ammonium chloride, bicarbonate dithionite, NaOH, HCl extraction) in river water sample. In rainfall event in May and July, about 70 - 90 % of PP was bioavailable and that part were larger than PO4-P load from Yasu river, indicate that PP discharge from river have large impact on primary production in downward lake.