[M-IS19] [JJ] 生物地球化学

[MIS19-P07] 森林渓流水中の硝酸イオン濃度に与える乾性沈着・湿性沈着の影響

*梶谷 侑生¹、尾坂 兼一²、藤田 健斗¹、千代 真照¹、勝山 正則³、中村 高志⁴、西田 継⁴ (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 、3.京都大学学際融合教育研究推進センター グローバル生存学連携大学院ユニット、4.山梨大学大学院総合研究部国際流域環境研究センター )

キーワード：硝酸、渓流水、乾性沈着、湿性沈着、森林集水域

Nitrogen exported from forest is considered to affect the eutrophication in downstream ecosystems, therefore, the understanding of nitrogen export processes from forest is important. Recently, nitrogen deposition to terrestrial ecosystem is increasing and that enhance nitrate concentration exported from some forested watersheds. Nitrogen deposition to forest generally consists of dry and wet deposition of nitrogen, however, the influence dry deposition on nitrogen export from forested watershed has not clear compared with the influence of wet deposition. In this study, we measured nitrogen compounds concentrations in stream water, througfall and air in forested watersheds near highway to clarify the influence of dry deposition and wet deposition on streamwater nitrate concentration. We collected streamater in 23 sites, throughfall in 13 sites and nitrogen oxide aerosol in 8 sites at north part of Shiga prefecture. Stremawater was collected from March 2016 to November 2016 in a month interval, and throughfall and aerosol were collected from August 2016 in two weeks interval. Nitrate concentrations were higher in streamwater from forested watershed near highway. We will discuss the relationship between streamwater nitrate concentrations and wet and dry depostion in presentation.