Study on interaction between nitrogen cycle and nitrogen input/output in forested ecosystem.

• Project/Area Number: 25850114
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Forest science
• Research Institution: The University of Shiga Prefecture
• Principal Investigator: Osaka Ken'ichi 滋賀県立大学, 環境科学部, 助教 (30455266)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2015: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 森林 / 窒素 / 水文過程 / 安定同位体比 / 硝酸イオン / 降雨調査 / 森林流域 / 降雨時調査 / 大気降下物 / 負荷量 / 窒素循環 / 森林生態系 / 安定同位体 / 流域

Outline of Final Research Achievements

To determine the availability of atmospheric nitrate deposition on forested ecosystem we quantitatively evaluated the atmospheric nitrate passing through forest watersheds by measuring oxygen isotope of nitrate leaching at the rainfall events. 2.9-37.8% (average = 15.5%) of atmospheric nitrate deposition passed through the watershed, and that account for 3.1 to 49.8% (average = 26.4%) of nitrate leaching during rainfall events. This suggests the possibility that the nitrate leaching will increase immediately in the forested watershed when the amount of nitrate deposition increases.

Research Products

• [Journal Article] ヒノキ人工林集水域における表面流の発生とそれが集水域からの溶存態窒素流出に与える影響 (2015)
  • Author(s): 久郷達朗、尾坂兼一、川村湧也、永淵修
  • Journal Title: 陸水研究 Volume: 2 Pages: 27-37
  • Peer Reviewed
• [Journal Article] ヒノキ人工林集水域における表面流の発生と それが集水域からの溶存態窒素流出に与える影響 (2015)
  • Author(s): 久郷達朗、尾坂兼一、川村湧也、永淵修
  • Journal Title: 陸水研究 Volume: 2 Pages: 27-37
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] レジンコア法とテンションフリーライシメーター法を用いた森林土壌における無機態窒素移動量とその起源の測定 (2015)
  • Author(s): 藤田健斗、尾坂兼一、千代真照、永淵修、中村高志、西田継
  • Organizer: 日本地球惑星連合
  • Place of Presentation: 幕張
  • Year and Date: 2015-05-24
  • Int'l Joint Research
• [Presentation] Atmospheric nitrate discharge processes in rainfall events at forested watersheds: The availability of atmospheric nitrate for forested ecosystem (2014)
  • Author(s): Osaka, K., K. Komaki, Y., Kawamura, T., Kugo, T., Murata, T., Nakamura, K., Nishida, O., Nagafuchi
  • Organizer: American Geophysical Union
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2014-12-15 – 2014-12-19
• [Presentation] Transportation and consumption processes of atmospheric nitrate in forested watershed in Shiga prefecture, central Japan (2014)
  • Author(s): Kugo, T., K., Osaka, T., Nakamura, Y., Ii, M., Iwai, K., Nishida, O., Nagafuchi
  • Organizer: American Geophysical Union
  • Place of Presentation: サンフランシスコ
  • Year and Date: 2014-12-15 – 2014-12-19
• [Presentation] 森林生態系における大気降下物由来硝酸イオンの利用率に関する研究 (2014)
  • Author(s): 尾坂兼一，小牧直人，川村湧也，村田哲也，久郷達朗，中村高志，西田継，永淵修
  • Organizer: 日本地球惑星科学連合
  • Place of Presentation: 横浜
  • Year and Date: 2014-04-28 – 2014-05-02
• [Presentation] 硝酸イオンの酸素安定同位体比を用いた森林流域における窒素移動過程の解明 (2014)
  • Author(s): 久郷達朗，尾坂兼一，中村高志，伊井裕美，岩井美佐子，西田継，永淵修
  • Organizer: 日本地球惑星科学連合
  • Place of Presentation: 横浜
  • Year and Date: 2014-04-28 – 2014-05-02
• [Presentation] 森林生態系における大気降下物由来硝酸イオンの利用率に関する研究 (2014)
  • Author(s): 尾坂兼一、小牧直人、川村湧也、村田哲也、久郷達朗、中村高志、西田継、永淵修
  • Organizer: 日本地球惑星科学連合
  • Place of Presentation: 横浜市
• [Presentation] 硝酸イオンの酸素安定同位体比を用いた森林流域における窒素移動過程の解明 (2014)
  • Author(s): 久郷達朗、尾坂兼一、中村高志、伊井裕美、岩井美咲子、西田継、永淵修
  • Organizer: 日本地球惑星科学連合
  • Place of Presentation: 横浜市