土壌の炭素分解の温度感度と気候変動へのフィードバック
Eric A Davidson1, Ivan A Janssens
1The Woods Hole Research Center, PO Box 296, Woods Hole, Massachusetts 02543, USA. edavidson@whrc.org
Nature
|March 10, 2006
まとめ
地球上の土壌の炭素貯蔵庫は,大気よりも多くの炭素を保持しています. 気候変動は土壌の分解速度に影響しますが,複雑な土壌プロセスにより大気中の炭素に対する純効果は依然として不確実です.
科学分野:
- 土壌科学 土壌科学
- 気候科学 気候科学
- バイオジオケミストリー バイオジオケミストリー
背景:
- 土壌は,大気中の貯蔵量を上回る,世界の炭素を大量に貯蔵しています.
- 気候変動が土壌の炭素動態に及ぼす影響について議論され,潜在的正または負のフィードバックループが考えられます.
- 土壌の炭素フィードバックを理解することは,気候変動の予測に不可欠です.
研究 の 目的:
- 土壌の炭素分解の温度感度を調査する.
- 気候変動に対する土壌炭素のフィードバック効果に影響を与える要因を解明する.
- 温暖化に対する土壌の炭素の反応に関するコンセンサスの欠如に対処するために.
主な方法:
- 多様な土壌有機化合物とその分解運動の分析.
- 観測された"明らかな"温度感受性に対する環境制約の評価.
- 土壌の炭素分解の固有の対表面的な温度感度の評価.
主要な成果:
- 分解の固有の温度感受性は,土壌有機化合物によって大きく異なります.
- 環境的制約により,観察された分解温度感度が著しく低下する.
- これらの制約自体が気候に敏感であり,複雑さを増す可能性があります.
結論:
- 地球規模の土壌炭素貯蔵量に対する気候変動の純効果は,依然として不確実である.
- 正確な気候モデリングには,土壌の炭素分解の温度感度をよりよく理解する必要があります.
- 本質的および表面的な温度感受性とそれらの気候相互作用を解き放つためにさらなる研究が必要です.
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