Evaluation of carbon storage process into marine sediment based on new optical technology: non-destructive measurement of belowground production and degradation of seagrass

• Project/Area Number: 23657011
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Ecology/Environment
• Research Institution: Hokkaido University
• Principal Investigator: NAKAOKA Masahiro 北海道大学, 北方生物圏フィールド科学センター, 教授 (90260520)
• Co-Investigator(Kenkyū-buntansha): FUKUZAWA Karibu 北海道大学, 北方生物圏フィールド科学センター, 助教 (10456824) ; NAKAJI Tatsuro 北海道大学, 北方生物圏フィールド科学センター, 助教 (40391130)
• Project Period (FY): 2011 – 2012
• Project Status: Completed (Fiscal Year 2012)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2012: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2011: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: 光学センサー / アマモ場 / 炭素吸収能 / 細根生産量 / 有機物分解

Research Abstract

This project aims to establish a method for quantitatively estimating production and degradation rate of belowground parts of seagrass by adopting non-destructive optical measurement techniques developed in terrestrial ecosystem research. Firstly, an aquaculture experiment of eelgrass was conducted using indoor and outdoor aquaria to periodically monitor growth of rhizomes and roots using an optical scanner in non-destructive manner. It was revealed that the root biomass accounted ca. 3 % of a total biomass of eelgrass, but the whole belowground parts occupied 14% and contributed significantly as a sink of carbon in sediment. Secondarily, hyper spectral reflectance images of different-aged belowground parts of seagrass were captured at visible and near-infrared spectral region (446-894nm). The increase in age from 14-220 days reduced the reflectance of live fine roots mainly at visible spectral region. The dead seagrass parts showed low reflectance at whole spectral region. By developing the estimation model, root age and concentrations of carbon and nitrogen were predicted by the spectral reflectance at the error of 12-37% (rRMSE). In conclusion, it was shown that seagrass belowground production has clear seasonal cycle and contributes to blue carbon storage. It was firstly demonstrated that age of belowground parts, carbon and nitrogen balance can be determined non-destructively using spectral reflectance images.

Research Products

• [Presentation] スキャナを用いた海草・アマモの根の動態解析 (2012)
  • Author(s): 福澤加里部,仲岡雅裕,中路達郎,林奈津美
  • Organizer: 第37回根研究集会
  • Place of Presentation: 京都大学(京都市)
  • Year and Date: 2012-12-01
• [Presentation] スキャナを用いた海草・アマモの根の動態解析 (2012)
  • Author(s): 福澤 加里部，仲岡 雅裕，中路 達郎，林 奈津美
  • Organizer: 第37回根研究集会
  • Place of Presentation: 京都大学（京都市）
• [Book] Anupdated approach (2012)
  • Author(s): Fukuzawa, K., Dannoura, M. and Shibata, H
  • Total Pages: 395
  • Publisher: Springer-Verlag
• [Book] 植物科学の最前線 (2012)
  • Author(s): 中路達郎,野口亨太郎,小熊宏之
• [Book] 根圏動態研究における非破壊分光画像計測の可能性. In: 日本植物学会編 「植物科学の最前線」 (2012)
  • Author(s): 中路達郎, 野口亨太郎，小熊宏之
  • Publisher: BSJ-Review，WEB書籍http://bsj.or.jp/saizensen/
• [Book] Measuring roots: An updated approach (2012)
  • Author(s): Fukuzawa K, Dannoura M, Shibata H; in Stefano Mancuso (eds)
  • Total Pages: 395
  • Publisher: Springer-Verlag
• [Book] Regional comparison of the ecosystem services from seagrass beds in Asia
  • Author(s): Nakaoka, M., Lee, K-S., Huang, X., Almonte, T., Sidik Bujang, J., Kiswara, W., Ambo Rappe, R., Maryam Yaakub, S., Prabhakaran, M.P., Abu Hena M.K., Hori, M., Zhang, P., Prathep, A. and Fortes, M. D
  • Publisher: Springer (in press)