Ecosystem interactions in coastal areas for improved carbon stock functions

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04679
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Osaka Prefecture University College of Technology
• Principal Investigator: OTANI SOSUKE 大阪府立大学工業高等専門学校, その他部局等, 准教授 (60554219)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 沿岸域 / 生態系 / 炭素固定 / 二酸化炭素フラックス

Outline of Final Research Achievements

The objective of this study was to clarify the interaction between carbon dioxide fluxes at the water surface and the ecosystems that contribute to the fluxes in the coastal area of Osaka Bay. The spatial distribution of carbon dioxide fluxes at the water surface and in sediments on 13 tidal flats suggests that carbon dioxide tends to be released from the water surface, while carbon dioxide is released from sediments as organic matter decomposition is accelerated of the sediments in low tide. The carbon dioxide flux at the water surface of the Amagasaki Canal showed absorption trend, indicating that the canal absorbs carbon dioxide from the air into the water. Furthermore, it was found that 8.6% of organic carbon was transferred from primary producers to secondary producers throughout the year.

Free Research Field

沿岸環境工学

Academic Significance and Societal Importance of the Research Achievements

ブルーカーボン機能の生態系相互作用を明らかにすることを目的に，大阪湾沿岸域において，13の干潟の調査を行った．干潟では水面から二酸化炭素は放出傾向であり，堆積物は干出中に有機物の分解が促進されて二酸化炭素は放出していることが考えられた．さらに湾奥部の尼崎運河において，年間を通して大気から水面に二酸化炭素は吸収傾向であった．また，水中に吸収された二酸化炭素は植物プランクトンに吸収されて高次の捕食者である動物プランクトンと貝に有機炭素の形で炭素が移行していることを示した．このように炭素固定に関わる炭素フローを定量的に示すことで二酸化炭素のガス交換とそれに関わるメカニズムを総合的に明らかにした．