土壌の水分と大気のフィードバックは,土地の炭素吸収の変動性を支配する
Vincent Humphrey1, Alexis Berg2, Philippe Ciais3
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA. vincent.humphrey@caltech.edu.
Nature
|April 1, 2021
まとめ
土壌の水分の変動は,毎年地球上の土地の炭素吸収の変化の90%を牽引し,主に光合成に影響します. 土壌の水分と大気のフィードバックは気候効果を拡大し,地上の炭素循環と大気中の二酸化炭素レベルに影響を与えます.
科学分野:
- 地球システム科学
- エコロジー
- 気候科学
背景:
- 陸上の生態系は,年ごとに炭素吸収の変動によって大気中の二酸化炭素 (CO2) の濃度を調節する上で重要な役割を果たします.
- 地球規模での炭素吸収の変動に 温度と水資源の正確な影響は まだ不明です
研究 の 目的:
- 土壌の水分と気温が地球全体の炭素吸収に与える影響を定量化する.
- 土壌の水分が土地の炭素吸収に影響を与えるフィードバックループを含むメカニズムを調査する.
主な方法:
- 気候変数の土地の炭素吸収への影響を解明するために,因数的な気候モデルシミュレーションを使用した.
- 温度と湿度に対する土壌湿度-大気フィードバックによる土壌湿度の間接的な影響を分析した.
主要な成果:
- 土壌の湿度の変動は,主に光合成に影響を与えることで,世界の土地の炭素吸収の年間変動の90%を占めています.
- 生態系の反応は主に間接的であり,土壌の水分と大気のフィードバックによって媒介され,気候の異常と土壌の水圧を拡大します.
- モデル化された土地の炭素吸収の変動は,主に温度と蒸気圧の赤字によって引き起こされ,どちらも土壌の水分によって制御されます.
結論:
- 土壌の水分は,地球上の土地の炭素吸収の変動を制御する主要な要因です.
- 土壌の水分と大気のフィードバックメカニズムを考慮することは,気候変動に対する炭素循環の反応を正確に予測するために不可欠です.
- 発見は,地球規模の炭素循環研究と地域の干ばつ影響研究の両方で,土壌の水分ダイナミクスの重要性を強調しています.
関連する概念動画
The Soil Ecosystem
23.7K
Plants obtain inorganic minerals and water from the soil, which acts as a natural medium for land plants. The composition and quality of soil depend not only on the chemical constituents but also on the presence of living organisms. In general, soils contain three major components:
23.7K
The Carbon Cycle
42.3K
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
42.3K
Regulation of Transpiration by Stomata
29.8K
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
29.8K
What is Climate?
19.7K
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
19.7K
Adaptations that Reduce Water Loss
27.1K
Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
27.1K
Global Climate Change
27.8K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
27.8K


