Belowground roots production and decomposition processes of major mangrove species and site environments

2016 Fiscal Year Final Research Report

• Project/Area Number: 25282084
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: Nanzan University
• Principal Investigator: FUJIMOTO Kiyoshi 南山大学, 総合政策学部, 教授 (50329752)
• Co-Investigator(Kenkyū-buntansha): 渡辺 信 琉球大学, 熱帯生物圏研究センター, 准教授 (10396608) ; 小野 賢二 国立研究開発法人森林総合研究所, その他部局等, 研究員 (30353634) ; 井上 智美 国立研究開発法人国立環境研究所, その他部局等, 研究員 (80435578)
• Co-Investigator(Renkei-kenkyūsha): TANIGUCHI Shingo 琉球大学, 農学部, 教授 (80444909)
• Research Collaborator: TABUCHI Ryuichi ; HIRAIDE Masakazu ; OGAWA Tomomi ; NISHINO Yumi
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: マングローブ / 根生産量 / 地下部生産速度 / 地下部分解速度 / 窒素固定機能 / 立地環境 / ミクロネシア連邦ポンペイ島 / 西表島

Outline of Final Research Achievements

We examined fine roots accumulation and decomposition rates and nitrogen fixation ability for major mangrove species of Pohnpei Island in Micronesia and Iriomote Island. Fine roots accumulation rates were 40 to 50 t/ha/year in Pohnpei except inland sites of three species, which were around 25 t/ha, and 4 to 9 t/ha/year in Iriomote. Root litter residual ratios for a year were 40 to 85 % in Pohnpei except seaward site of Rhizophora stylosa, which was 8 %, and 50 to 60 % in Iriomote. Activation energy of nitrogen-fixing reaction was higher in rhizosphere than non-rhizosphere for all investigated trees. Nitrogen fixation activity in Pohnpei was highest compared with other regions.

Free Research Field

自然地理学、地生態学