北半球の微生物源の減少によって説明されるメタンの成長率の低下
Fuu Ming Kai1, Stanley C Tyler, James T Randerson
1Department of Earth System Science, University of California, Irvine, California 92697, USA. fmkai@smart.mit.edu
Nature
|August 12, 2011
まとめ
大気中のメタン (CH4) の増加は,北半球の微生物の源が減少したため,特にアジアの米栽培からの減少により,減速した. この発見は,ミレニアムの周りの大気中のメタンパズルを明らかにします. キーワード:大気中のメタン,微生物の源,米栽培.
科学分野:
- 大気化学と気候科学.
- バイオジオケミカルサイクルと温室効果ガス排出量
背景:
- 大気中のメタン (CH4) レベルは20世紀を通して上昇し,再び上昇する前に減速した.
- 以前の研究では,化石燃料,湿地,農業,およびヒドロキシル (OH) 沈殿物が減速の潜在的な原因であると指摘されていた.
研究 の 目的:
- 大気中のメタンの増加率の20世紀後半の減速の主な要因を調査する.
- 同位体分析を使用して,さまざまなメタン源とシンクからの貢献を区分する.
主な方法:
- 大気中のCH4混合比率と炭素同位体比率 ((13) C/ ((12) C) の同期タイムシリーズの分析.
- CH4の進化をシミュレートするために2つのボックスの大気モデルを使用しました.
- 観測された同位体変化を,源とシンクの変化のモデル化されたシナリオと比較した.
主要な成果:
- 北半球における微生物源の減少が,観測されたCH4成長率の変化を最もよく説明する.
- 同位体データは,減速の主な原因として,化石燃料排出量の減少を排除しています.
- 北半球の農業の排出量,特にアジアの米栽培による排出量は,肥料の使用と水管理に関連した排出量の減少の約51%を占めています.
結論:
- 20世紀後半の大気中のメタンの減速は,主に北半球における微生物の排出量の減少によって引き起こされた.
- アジアの米栽培の変化は,この減少に大きく貢献した.
- 微生物によるメタンの源と農業慣行に関するさらなる研究が必要である.
関連する概念動画
Metabolism of Chemolithotrophs
1.3K
Chemolithotrophs are microorganisms that obtain energy by oxidizing inorganic molecules such as hydrogen gas (H₂), ammonia (NH₃), reduced sulfur compounds (H₂S, S²⁻), and ferrous iron (Fe²⁺). Unlike heterotrophic organisms that rely on organic carbon, chemolithotrophs transfer electrons from these inorganic donors to the electron transport chain (ETC), generating a proton motive force (PMF) that drives ATP synthesis through oxidative phosphorylation.
1.3K
Overview of Archaea
1.9K
Archaea, named after the Archaean eon, represent a unique domain of life, distinct from bacteria and eukaryotes, with remarkable traits. Their cellular and molecular features, ecological adaptability, and industrial relevance highlight their importance in understanding life processes and leveraging biotechnology.Cellular and Molecular CharacteristicsA defining feature of archaea is their unique membrane composition. Archaeal membranes contain ether-linked isoprenoid lipids, which confer...
1.9K
Microbial Interactions: Mutualism
99
Mutualism is a symbiotic interaction in which all participating organisms benefit. These relationships can be obligate or facultative and are fundamental to ecosystem functions across diverse biological systems.Plant–Fungi MutualismOne well-known example is the association between plant roots and mycorrhizal fungi, such as Rhizophagus species. The fungal hyphae penetrate the root hairs and the epidermis, forming an extensive hyphal network that establishes a symbiotic association. Through...
99
Microbes and Methanogenesis
108
Methanogenesis is a critical microbial process in anaerobic ecosystems responsible for the biological production of methane, a potent greenhouse gas and valuable biofuel. This metabolic pathway is primarily facilitated by methanogenic archaea, which thrive in anoxic environments such as wetlands, sediments, and animal gastrointestinal tracts. The absence of oxygen in these habitats prevents aerobic respiration, thereby favoring alternative biochemical pathways for organic matter degradation.In...
108
Marine Microbial Ecology
74
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
74
Microbes and Climate Change
103
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
103


