Relationship between Soil Microbial Diversity and Priming Effects in Forest Ecosystems

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K20434
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Nagoya University (2022); Kyoto University (2020-2021); Tokyo University of Agriculture and Technology (2019)
• Principal Investigator: Sawada Kozue 名古屋大学, 生命農学研究科, 特任助教 (60795285)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 土壌微生物 / 土壌有機物 / プライミング効果 / 森林生態系

Outline of Final Research Achievements

This study elucidated the effects of differences in mycorrhizal types (ectomycorrhizal and arbuscular mycorrhizal fungi), soil acidity, and N and P limitation on microbial community composition and diversity and the effect of C addition to promote organic matter degradation (priming effect) in forest soils.
The results revealed that differences in mycorrhizal types significantly affected microbial community composition and diversity, but not the priming effect. The priming effect was suppressed in highly acidic soils in Japan. The priming effect through P mining occurred in P-poor tropical forest soils, and the priming effect through N mining occurred in N-poor temperate forest soils. These results are essential for accurately predicting C dynamics in forest soils.

Free Research Field

土壌生化学

Academic Significance and Societal Importance of the Research Achievements

プライミング効果は、菌根菌タイプの違いや微生物群集組成・多様性の違いよりも、土壌酸性度の違いや窒素・リン制限の違いの影響の方が大きいことが分かった。つまり、樹種選択による微生物群集組成の改変は、プライミング効果にはあまり影響しないかもしれない。一方、土壌酸性化は有機物分解を抑制しうること、適切な養分バランスが森林土壌の炭素蓄積に重要であることが示された。以上の成果は、森林土壌における炭素動態の予測精度の精緻化と、CO2放出量の抑制や土壌炭素量の増加に向けての適切な管理と利用法の考案につながる重要な成果である。