熱帯雨林の干ばつによる死は 水力によるもので 炭素による死ではありません
L Rowland1, A C L da Costa2, D R Galbraith3
1School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FF, UK.
Nature
|November 24, 2015
まとめ
熱帯雨林は 干ばつによる死亡に 直面していますが 主な原因は 炭素の不足ではなく 水力学です 長い干ばつ後の水力故障には 大きな木が最も脆弱で 水力輸送の問題が木の死を引き起こすことを示しています
科学分野:
- エコロジー
- 森林科学
- 気候変動の生物学
背景:
- 旱は熱帯雨林に重大な脅威をもたらし,木々の存続に様々な時間尺度で影響を及ぼします.
- 干ばつ条件下での木の死亡率を駆動する正確なメカニズム,特に炭素の飢餓と水力障害の役割は完全に理解されていません.
研究 の 目的:
- 干ばつに苦しむ熱帯雨林の樹木死亡の主な原因であるかどうかを調査する.
- 樹木における非構造炭水化物 (NSC) 貯蔵と水力機能に対する実験的な干ばつによる長期的影響を分析する.
主な方法:
- ブラジルのアマゾンの熱帯雨林で 実施された最も長い干ばつ実験のデータを使いました
- 実験的に乾燥した土地と対照地間のNSC濃度と樹木死亡率の比較
- 死亡リスクに影響を与える要因として水力劣化と木の大きさを評価した.
主要な成果:
- 乾燥した森林では10年以上に渡って土壌の水分が減少したため,木々の死により生物量が大幅に減少しました.
- より大きな木は,より小さな木と比較して,水力的な劣化と死亡のリスクが高くなります.
- 炭水化物不足の証拠は見つかりませんでした.NSC濃度は同じままで,乾燥した木の成長率は低下しませんでした.
結論:
- この熱帯雨林の生態系における 干ばつによる木の死亡の主な原因は 炭酸ガスの不足ではなく 水力障害です
- 長期にわたる干ばつが大きな木に 莫大な影響を及ぼし 水力輸送の障害に対する 脆弱性を強調しています
- この発見は 乾燥した環境下での樹木の生存に 水路の維持が 極めて重要であることを強調しています
関連する概念動画
Responses to Drought and Flooding
12.4K
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.
12.4K
Adaptations that Reduce Water Loss
28.9K
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.
28.9K
Threats to Biodiversity
27.8K
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
27.8K
Disorder of Water Balance
2.8K
Water balance disorders are medical conditions that occur when there is a deviation from the body's water volume or osmolarity, disrupting normal homeostasis and leading todehydration, hypotonic hydration, hyperhydration, edema, or water intoxication.
Dehydration
Dehydration occurs when the body loses fluids (particularly water).
Causes:
The major causes of dehydration include excessive sweating, fever, vomiting, diarrhea, and diuresis.
Signs and Symptoms:
Symptoms primarily include intense...
Dehydration
Dehydration occurs when the body loses fluids (particularly water).
Causes:
The major causes of dehydration include excessive sweating, fever, vomiting, diarrhea, and diuresis.
Signs and Symptoms:
Symptoms primarily include intense...
2.8K
Xylem and Transpiration-driven Transport of Resources
27.9K
The xylem of vascular plants distributes water and dissolved minerals that are taken up by the roots to the rest of the plant. The cells that transport xylem sap are dead upon maturity, and the movement of xylem sap is a passive process.
27.9K
Primary Motives: Hunger and Thirst
1.6K
Hunger and thirst are fundamental physiological drives crucial for maintaining homeostasis and ensuring the survival of both humans and animals. These drives are regulated through complex interactions between the brain, hormones, and sensory receptors.
Hunger arises when the brain detects changes in the body's nutrient levels, including glucose, lipids, amino acids, and hormones such as ghrelin and leptin. The hypothalamus plays a central role in hunger regulation. The lateral hypothalamus...
Hunger arises when the brain detects changes in the body's nutrient levels, including glucose, lipids, amino acids, and hormones such as ghrelin and leptin. The hypothalamus plays a central role in hunger regulation. The lateral hypothalamus...
1.6K


