何十年にもわたる火災撲滅によるサバンナの炭素貯蔵量の限られた増加
Yong Zhou1,2, Jenia Singh3, John R Butnor4
1Yale Institute for Biospheric Studies, Yale University, New Haven, CT, USA. yong.zhou@yale.edu.
Nature
|March 17, 2022
まとめ
アフリカのサバンナでの火災の抑制は 樹木が大きく成長したにも関わらず わずかに炭素の蓄積を増加させました 地下の炭素は 頻繁に燃え上がる地域では 限られた貯蔵可能性と 生物多様性の喪失の可能性を示唆しています
科学分野:
- エコロジー
- 気候科学
- 炭素サイクル
背景:
- サバンナは 重要な地球規模の生態系で 火と炭素のダイナミクスを通して 気候に影響を与えます
- 火災抑制と植林は 炭素を吸収する戦略として提案されています
- 変化した火災状態でのサバンナの炭素貯蔵量を定量化することは極めて重要ですが,不足しています.
研究 の 目的:
- アフリカのサバンナで長期にわたる火災への炭素反応を直接推定する.
- 燃焼抑制が炭素貯蔵と樹木覆面の動態に与える影響を評価する.
- 地下炭素がサバンナに蓄積する可能性を評価する.
主な方法:
- 火災を除外した60年以上の間,生態系全体の炭素貯蔵の変化を直接測定した.
- 樹木覆面の量化変化と関連する炭素増加
- 頻繁に燃えるサバンナの地下炭素貯蔵庫 (バイオマスと土壌) を分析した.
主要な成果:
- 火災排除は生態系における炭素貯蔵量を35.4%±12%だけ増加させた.
- 樹木の覆いは78.9%±29.3%増加し,炭素の増加は予想より著しく低下した.
- 頻繁に燃え上がるサバンナは 地下にある生物質や深い土壌に 大量の炭素を貯蔵します
結論:
- サバンナの10年分の炭素貯蔵力は,特に地下にある炭素貯蔵池を考慮すると,軽視される可能性があります.
- 現在の火災撲滅と植林戦略は 炭素吸収の利点を過大評価しているかもしれません
- 変化した火災はサバンナの生態系に 生物多様性と機能的損失をもたらします
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