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北極森林の羽毛モスのカーペットにおける窒素固定の定量化
Thomas H DeLuca1, Olle Zackrisson, Marie-Charlotte Nilsson
1School of Forestry, The University of Montana, Missoula, Montana 59812, USA. thd@forestry.umt.edu
Nature
|November 1, 2002
まとめ
北極森林における生物学的窒素固定は過小評価されています. サイアノバクテリアと羽毛モスの間の新しい共生は,窒素を大幅に固定し,これらの生態系のための新しい源を明らかにします.
科学分野:
- エコロジー エコロジー エコロジー
- 環境科学 環境科学
- 微生物学 微生物学とは
背景:
- 生物学的窒素 (N) 固定は,自然生態系にとって極めて重要です.
- 北極森林における窒素の起源は,依然としてほとんど不明である.
- 現在,北極森林におけるN固定の推定値は非常に低いと考えられています.
研究 の 目的:
- 北極森林の生態系における窒素蓄積の源を調査する.
- ボレアル地域におけるこれまで認識されていない窒素固定過程を特定する.
- 新しく発見されたシンバイオシスのN固定率を定量化するために.
主な方法:
- 北部のスカンジナビアとフィンランドの北極の森林でのフィールドサンプリング.
- 羽毛モス (Pleurozium schreberi) に関連する共生微生物の識別.
- 同位体法 (暗黙) を用いて窒素固定速度の定量化.
主要な成果:
- サイアノバクテリア (Nostoc sp.) との間の共生関係が特定されました. そして,Pleurozium schreberi. と書かれています.
- この共生は北極の森で推定1.52.0 kgのN ha−1 yr−1を固定する.
- この割合は,これらの生態系におけるN固定が以前に推定されたものより大幅に高い.
結論:
- シアノバクテリア-羽毛モスの共生は,北極林における窒素の重要な源である.
- 以前の評価では,これらの生態系における窒素の総固定量を過小評価した可能性がある.
- この発見は,北極林の生態学における窒素循環を再評価することを必要としています.
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