Carbon allocation in woody organs of Abies seedlings

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20591
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0603:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Tanabe Tomoko 京都大学, 生存圏研究所, 研究員 (40967402)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 気候変動 / 森林 / 生産量 / 樹体内炭素分配 / パルスラベリング / 炭素安定同位体 / フェノロジー / Abies

Outline of Final Research Achievements

Growth periods were measured for the elongation and radial growth of stems and branches, and pulse labeling experiments were conducted using stable carbon isotopes as a tracer in three-yr-old Abies firma seedlings. Both stems and branches started radial growth after the cessation of elongation growth. Differences in growth periods revealed that the climatic factors influencing elongation and radial growth may differ. Seasons of 2023 were divided based on the results of growth periods, and only the individuals labeled during those periods were used for isotope analysis. These samples remain to be prepared and I continue to work on this task to reach the original objective of this project.

Free Research Field

森林科学

Academic Significance and Societal Importance of the Research Achievements

木部生産に使われた炭素は長期間樹体内に留まるため、中長期的な地球の炭素循環を考えるうえで重要なパートである。木部は伸長成長と肥大成長を毎年繰り返すことで体積が増え、地上高1.3 ｍ位置の肥大量は木部生産量の指標とされてきた。しかし本成果を受け、モミの伸長と肥大は成長期間が重複しておらず、成長中の気象条件が全く異なることが明らかとなった。これは、成長に影響する気象の要素やその時期が、伸長と肥大とでは異なることを示唆している。従来の指標で年単位の木部生産量を評価して気象と解析する方法では、少なくともAbiesにおいて、個体レベルの木部体積増加に影響する要素を抽出できていないかもしれない。