日本地球惑星科学連合2018年大会

講演情報

[JJ] ポスター発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS14] 生物地球化学

2018年5月23日(水) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:木庭 啓介(京都大学生態学研究センター)、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、共同)、山下 洋平(北海道大学 大学院地球環境科学研究院)

[MIS14-P02] 都市近郊林における大気由来のリン沈着量の計測

張 璐1、*智和 正明1鄭 聖勳1井手 淳一郎2大槻 恭一1 (1.九州大学農学部附属演習林、2.九州大学 持続可能な社会のための決断科学センター)

キーワード:大気窒素沈着、乾性沈着、リン酸塩、溶存有機リン、林内雨

Atmospheric P deposition contributes significantly to P source as well as rock weathering. However, quantitative information is limited about atmospheric P deposition, especially dry deposition, when evaluating the effects of elevated N deposition on N saturation in temperate forested ecosystems where other nutrients including P could be limited. This study measured atmospheric P deposition using throughfall method as well as bulk rainfall to evaluate the contribution of atmospheric P deposition to P cycling in advanced stage of N-saturated forested ecosystems, suburban area, Fukuoka, western Japan. Throughfall and stemflow were collected in the forested site and rainfall was also collected at nearby open sites from October 2016 to September 2017. Dissolved total phosphorus (DTP), consisting of phosphate (PO43-) and dissolved organic phosphorus (DOP), were measured. Atmospheric N deposition was 9.3 kg N ha-1 yr-1 via bulk deposition and 17.6 kg N ha-1 yr-1 via throughfall plus stemflow, indicating high atmospheric N deposition enough to potentially induce N saturation in forested ecosystems. Atmospheric wet and dry deposition of DTP was 0.036 and 0.009 kg P ha-1 y1-1, respectively. Kosa phenomenon increased dry deposition of particulates including Ca2+ and DTP. However, total atmospheric P deposition in this study sites was considerably lower than the referred values in other sites, suggesting that the lower atmospheric P deposition at the study site may contribute to advanced N saturation in forested ecosystems. Overall, we highlight the need for information about atmospheric P deposition when assessing the impacts of N deposition.