Initial hydraulic failure followed by late-stage carbon starvation leads to drought-induced death in the tree
| Autor: | Yuri, Kono, Atsushi, Ishida, Shin-Taro, Saiki, Kenichi, Yoshimura, Masako, Dannoura, Kenichi, Yazaki, Fuku, Kimura, Jin, Yoshimura, Shin-Ichi, Aikawa |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Communications Biology |
| ISSN: | 2399-3642 |
| Popis: | Drought-induced tree death has become a serious problem in global forest ecosystems. Two nonexclusive hypotheses, hydraulic failure and carbon starvation, have been proposed to explain tree die-offs. To clarify the mechanisms, we investigated the physiological processes of drought-induced tree death in saplings with contrasting Huber values (sapwood area/total leaf area). First, hydraulic failure and reduced respiration were found in the initial process of tree decline, and in the last stage carbon starvation led to tree death. The carbohydrate reserves at the stem bases, low in healthy trees, accumulated at the beginning of the declining process due to phloem transport failure, and then decreased just before dying. The concentrations of non-structural carbohydrates at the stem bases are a good indicator of tree damage. The physiological processes and carbon sink-source dynamics that occur during lethal drought provide important insights into the adaptive measures underlying forest die-offs under global warming conditions. Yuri Kono et al. show that drought-induced tree death is caused by initial hydraulic failure followed by carbon starvation. They find that the loss of the carbon sink-source balance in stem bases due to phloem transport failure is the key factor governing wilting, providing insight to developing adaptive measures to prevent forest die-offs under global warming conditions. |
| Databáze: | OpenAIRE |
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