アマゾン流域の水分流域における地表土プロセスによる川の水中のカチオン濃度の制御
D Markewitz1, E A Davidson, Figueiredo Rd
1The Woods Hole Research Center, Woods Hole, Massachusetts 02543, USA. dmarke@smokey.forestry.uga.edu
Nature
|April 12, 2001
まとめ
気候が強いアマゾンの土壌では,川水の化学反応は表面土壌の洗浄によって制御されるが,深層の気象によるものではない. 森林の燃焼は土壌を豊かにし,生物学的媒介によるカチオン浸出によって将来の森林の再生を支える.
科学分野:
- 地質化学 地質化学
- 熱帯土壌科学 トロピカル土壌科学
- 水文学 水文学とは
背景:
- 温帯の生態系における水の化学反応は,主に岩石の気象によるものです.
- 古い熱帯土壌の水化学の理解は限られている.
- 炭酸による主要な鉱物の溶解は,温帯の土壌において鍵となる.
研究 の 目的:
- 流水化学の原動力を,気象が強いアマゾンの流域で調査する.
- 熱帯と温帯の土壌における気象化と浸出プロセスを比較する.
- 過去の森林の燃焼が土壌のカチオンの利用可能性に及ぼす長期的な影響を評価する.
主な方法:
- ブラジルのアマゾン流域の1万ヘクタールの土壌と水の化学データを集めて分析した.
- 流水中のカチオン濃度とアルカリ性は排水と相関しています.
- 水の化学における季節的パターンを調べた.
主要な成果:
- 流水中のカチオン濃度とアルカリ性は排水と正に相関しており,表面洗浄を示しています.
- 観測されたパターンは温帯の生態系とは異なるので,気象制御の違いが示唆される.
- 過去の森林焼却は土壌を豊かにし,雨季のカチオン流出を増加させる可能性がある.
結論:
- この高度に天候の影響を被る土壌の流水流域の流水化学は,主に,生物学的媒介によるCO2生産によって引き起こされる,地表土の洗浄によって制御されます.
- 年間キャチオンインプットとアウトプットはバランスが取られており,将来の森林再生のためにキャチオンが利用可能であることを保証します.
- 発見は温帯の生態系と対照的であり,独特の熱帯土壌水理学的プロセスを強調しています.
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