Evaluation of high temperature and drought tolerance of tropical mountain forest and lowland tropical rain forest trees in Southeast Asia

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07795
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Forest science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Tanaka Kenzo 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (30414486)
• Co-Investigator(Kenkyū-buntansha): 市榮 智明 高知大学, 教育研究部自然科学系農学部門, 准教授 (80403872)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 熱帯雨林 / 熱帯山地林 / 光合成 / 気孔コンダクタンス / 気候変動 / 乾燥耐性 / 高温順化 / 水利用効率

Outline of Final Research Achievements

Strong drought and high temperature due to climate change have been predicted in tropical lowland rain forests and tropical mountain forests in Southeast Asia. However, the effects of those drought and high temperature on trees are unknown in such forests. We conducted artificial drought experiments on lowland tropical rainforest trees to evaluate their drought tolerance. In addition, seedlings of tropical mountain forest trees were moved to lowlands with high temperature to evaluate changes on their growth rate and photosynthetic function. We found that the drought tolerance was largely different depending on the tree species in lowland tropical rain forest. Mountain forest tree seedlings under high temperature conditions can acclimate optimum photosynthetic temperature but their growth rate decreased due to increasing respiration rate.

Free Research Field

樹木生理生態学

Academic Significance and Societal Importance of the Research Achievements

この研究の成果は、将来干ばつが頻発した際の熱帯雨林の樹木の成木と実生の生理生態的な応答や、乾燥ストレスへの順化が可能な閾値の推定に役立つ成果である。また、これまでほとんど分かっていなかった熱帯山地林樹種の光合成や呼吸速度の高温順化能力や成長への影響の定量的な評価につながる。本研究で得られた、光合成や呼吸速度の温度依存性のパラメータや、乾燥に対する光合成や気孔開度の応答特性は、プロセスベースの森林動態や植生モデルに実測値を基にした変数として利用でき、気候変動の影響を考慮した東南アジアの熱帯雨林と熱帯山地林の森林動態・植生変動の予測に貢献できる。