Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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Outline of Final Research Achievements |
An increase of tree mortality due to drought is expected as global warming is progressing. However, the mechanisms of drought-induced mortality remain poorly understood. I studied hydraulic failure and carbon starvation as core traits involved in the stress response mechanisms in Japanese larch (Larix kaempferi) and Todo fir (Abies sachalinensis) saplings. Needles were more vulnerable to hydraulic failure than stems in both species. The hydraulic failure in needles was associated with a decrease in the photosynthetic rate but not with plant death. Under rapid soil drying conditions, plants died when stem hydraulic conductivity decreased by 88 %. Transformation from starch to sugar was observed in saplings just before death induced by rapid drought, whereas the total amount of starch and sugar did not decrease significantly, suggesting carbon starvation was not an important cause of death.
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