Elucidating effects of drought stress on stem respiration in Japanese cedar trees

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05736
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Masatake Araki 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 (80353564)
• Co-Investigator(Kenkyū-buntansha): 壁谷 大介 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 (30353650) ; 阪田 匡司 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 (50353701)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: スギ / ヒノキ / 乾燥ストレス / 温暖化 / 呼吸 / 蒸散 / 土壌呼吸

Outline of Final Research Achievements

We examined effects of soil drought, which was caused by the throughfall exclusion experiment for the consecutive three years, on shoot respiration, transpiration and soil respiration rates in a mature Japanese cedar stand. Transpiration rates and soil respiration rates were reduced in accordance with soil drought. Whereas, shoot respiration rates of cedar trees were not affected by soil drought.
Additionally, we developed a model for predicting stem CO2 efflux of mature Japanese cypress trees by using already obtained data. The model included the process that temperature sensitivity of stem respiration varied with the ambient temperature (temperature acclimation). Predictions by our model demonstrated that the extent of increase in stem CO2 efflux with future warming was reduced by incorporating the temperature acclimation in comparison with a conventional model which assumed constant temperature sensitivity.

Free Research Field

森林生態学

Academic Significance and Societal Importance of the Research Achievements

我が国の主要な造林樹種であるスギとヒノキについて、生理学的な観点から乾燥ストレスや気温上昇の影響を明らかにしたことは、気候変動が人工林に及ぼす影響を予測するための炭素収支モデルの精緻化に貢献するとともに、人工林の適応策を考えるうえで有用な知見を提供する。