日本地球惑星科学連合2023年大会

講演情報

[E] 口頭発表

セッション記号 B (地球生命科学) » B-BC 生物地球化学

[B-BC02] Methane in terrestrial and aquatic ecosystems: from microbes to the atmosphere

2023年5月26日(金) 15:30 〜 16:45 103 (幕張メッセ国際会議場)

コンビーナ:Daniel EPRON(Kyoto University)、浅川 晋(名古屋大学)、Patra Prabir(Research Institute for Global Change, JAMSTEC)、坂部 綾香(京都大学)、Chairperson:Daniel EPRON(Kyoto University)

15:30 〜 15:45

[BBC02-01] Tropical trees and methane exchange: How trees help solve problems in regional and global methane budgets.

★Invited Papers

*Vincent Gauci1 (1.School of Geography, Earth and Environmental Sciences, University of Birmingham, UK)

キーワード:trees , methane, wetlands, forests, Paris Agreement

Methane, the second most important greenhouse gas after carbon dioxide has seen recent rapid growth in atmospheric concentration. If this increase continues at the current rate it is likely to add an additional 0.5 W/m2 to Earth’s radiative balance by 2100 which would threaten our ability to meet Paris Agreement climate obligations. Given the role of this powerful, but short-lived greenhouse gas in determining future climate there is increased interest in fully understanding the methane cycle including natural contributions to the atmospheric methane burden. However, there have been problems, chiefly surrounding resolving regional and global methane budgets and reconciling the ways they are calculated via so called ‘bottom up’ and ‘top down’ approaches.
I will present findings that shed light on how the woody surfaces of trees that dominate productivity in tropical ecosystems such as peatlands, seasonal floodplains and upland forest, each of which were previously thought to be neutral in the exchange of methane, are now known to be important mediators of this trace gas. These interactions are examined in detail at a range of scales as they present opportunities in helping to quantify and account for prior gaps in regional budgets while also identifying sources of new complexity and uncertainty with work needed to understand hydrological, species and within and between-tree variability.
I demonstrate the importance of understanding tree methane exchange for SE Asian peatlands and the Amazon methane budget, and present new findings that show how riparian trees can remain sources of methane when not flooded with implications for broader tropical methane budgets. I further present findings on methane exchange in upland tropical trees, about which there has been much conflicting information. This new evidence, spanning climate gradients, further implicates upland trees in determining past changes in atmospheric methane concentration with examples drawn from specific times in Earth history. I conclude by highlighting future areas of importance in this growing area of ecosystem biosphere/atmosphere exchange research at a time when forest expansion is promoted in order to meet Paris agreement targets.