2022 Fiscal Year Final Research Report
Belowground carbon dynamics in permafrost forests with different active layer depths
Project/Area Number |
16H05790
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 海外学術 |
Research Field |
Forest science
|
Research Institution | Forest Research and Management Organization |
Principal Investigator |
Noguchi Kyotaro 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 (70353802)
|
Co-Investigator(Kenkyū-buntansha) |
森下 智陽 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 (90391185)
|
Project Period (FY) |
2016-04-01 – 2021-03-31
|
Keywords | 細根成長 / クロトウヒ / 下層植生 / 斜面位置 / 活動層 / 林床蘚類 |
Outline of Final Research Achievements |
In permafrost black spruce stands on a north facing slope in Interior Alaska, litterfall production rates and fine root growth rates were examined. Our results showed that litterfall production rates were greater at upper slope, where active layer depth was greater than at lower slope. On the other hand, fine root growth rates were similar among the plots across the slope positions, suggesting that allocation to fine roots was greater at lower slope than at upper slope. Fine root growth rates of black spruce trees were greater at upper slope than at lower slope, whereas those of understory plants were greater at lower slope in contrast. These results indicated that contribution of understory plants to fine root growth was greater than that of black spruce trees at lower slope, where active layer depths were shallower. Taken together, this study suggest that understory plants play a key role in belowground carbon dynamics at environments with shallower active layer depths.
|
Free Research Field |
森林生態学
|
Academic Significance and Societal Importance of the Research Achievements |
永久凍土林は凍結した土壌に莫大な量の炭素を蓄積しており、地球の炭素動態を理解する上で極めて重要な生態系だが、永久凍土林の炭素動態については不明な点が多い。本研究では、夏季に融解する凍土の深さが小さいほど、地下部への同化産物分配が大きくなることを明らかにした。また、凍土の融解が小さい林分ではツツジ科低木などの下層植生の細根成長量が大きく、地下部への炭素供給において重要な役割を担うと考えられた。これらの結果は、今後、緯度や地形により異なる、あるいは温暖化などの影響により変化する永久凍土上の森林の炭素動態を評価する上で、重要な知見と言える。
|