過去と将来の大気中のCO2に対する非線形草原の反応 ((2))
Richard A Gill1, H Wayne Polley, Hyrum B Johnson
1Department of Biology, Duke University, Durham, NC 27708-0340, USA. rgill@wsu.edu
Nature
|May 17, 2002
まとめ
土壌の有機物質は炭素を貯蔵できるが,その容量は限られている. 大気中の二酸化炭素 (CO2) の増加は,歴史的に植物の成長と土壌の炭素を増加させたが,将来の増加は窒素の利用により制限される可能性がある.
科学分野:
- エコロジー エコロジー エコロジー
- バイオジオケミストリー バイオジオケミストリー
- 気候科学 気候科学
背景:
- 大気中の二酸化炭素 (CO2) の濃度上昇は,土壌の炭素収縮によって緩和される可能性があります.
- 土壌の炭素貯蔵は,CO2に対する植物の反応と栄養素の利用可能性によって影響を受けます.
研究 の 目的:
- 大気中のCO2の過去および将来の増加に対する土壌の炭素貯蔵と窒素循環の反応性を調査する.
- 草原植物の生理学と土壌の炭素動態に対する高濃度のCO2の影響を理解する.
主な方法:
- 大気中のCO2濃度の連続的なグラデントを持つ草原の生態系を利用した (200〜550マイクロモルモル ((-1)).
- 測定された光合成速度,植物組織化学,土壌の炭素プール (旧・新),窒素の利用度.
主要な成果:
- 高濃度のCO2は,光合成の速度を高め,植物組織化学を変化させた.
- 土壌の炭素は低CO2で失われ,高CO2では古い炭素と新しい炭素のダイナミクスを相殺したため安定したままである.
- CO2グラデントに沿って,窒素の利用可能性が非線形で3倍に減少することが観察されました.
結論:
- 土壌の炭素貯蔵と窒素循環は,予測される将来のレベルよりも,過去のCO2増加に敏感です.
- 将来の CO2 の上昇の下での栄養素の制限の増加は,炭素吸収体として作用する土壌の能力を制限する可能性があります.
- 過去の土壌における炭素結合は有意であったかもしれないが,将来の可能性は栄養素の利用可能性によって制限されている.
さらに関連する動画
10:19A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function
Published on: November 21, 2015
07:32Monitoring Pedogenic Inorganic Carbon Accumulation Due to Weathering of Amended Silicate Minerals in Agricultural Soils.
Published on: June 4, 2021
関連する概念動画
01:50Global Climate Change
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.
02:04Regulation of Transpiration by Stomata
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.
01:57Adaptations that Reduce Water Loss
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.
02:41Responses to Drought and Flooding
Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.
01:28Carbon-dioxide Fixation
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
01:27Microbes and Climate Change
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...