Clarification of tree strategies for absorbing soil insoluble P through field survey and cultivation experiment

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20594
• 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: University of Yamanashi
• Principal Investigator: MUKAI Mana 山梨大学, 大学院総合研究部, 助教 (60909159)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 土壌 / リン / 細根 / 滲出物 / 有機酸 / ホスファターゼ / 森林

Outline of Final Research Achievements

There are several forms of phosphorus (P) in forest soils. Plant available P are soluble in soils and easy to get for trees, while insoluble P are existing as organic forms and/or as non-occluded P which are bound to non-crystalline minerals. However, it is not clarified how trees get these insoluble P from their roots.
The purpose of this study was to clarify tree strategies for capturing soil insoluble P through field survey and cultivation experiment. I studied the relationship between root traits such as phosphatase activities and the flux rates of exudates and rhizosphere soil P fractions. This study showed that trees would change the flux rates of root exudates and root phosphatase activities along soil P fraction concentrations (non-occluded P and organic P).

Free Research Field

森林生態学

Academic Significance and Societal Importance of the Research Achievements

野外では複数の環境要因が複数相互に影響し合っているため、野外で樹木のリン獲得の様子を知ることは非常に難しいが、本研究の多地点での比較研究を通して森林生態系のリン循環の様子が明らかになってきた。また、栽培実験も組み合わせることで、樹木の環境変動に応じた順応という点からの知見が得られたと考えられる。本研究成果は森林生態系でのリン循環や、将来的に火山活動などの地球環境改変イベントなどによりリン環境が変化した際の生物地球化学的な影響に関する将来的な予測のための知見を得られたという点で大きな波及効果があると期待できる。