2001 Fiscal Year Final Research Report Summary
Radial growth and cell wall structure of trees grown under elevated carbon dioxide concentrations
| Project/Area Number |
11460076
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林産学
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| Research Institution | Hokkaido University |
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Principal Investigator |
FUNADA Ryo Hokkaido Univ., Graduate School of Agr., Assoc. Prof., 大学院・農学研究科, 助教授 (20192734)
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| Co-Investigator(Kenkyū-buntansha) |
TAMAI Yutaka Hokkaido Univ., Graduate School of Agr., Assoc. Prof., 大学院・農学研究科, 助教授 (50281796)
SANO Yuzou Hokkaido Univ., Graduate School of Agr., Assist. Prof., 大学院・農学研究科, 助手 (90226043)
KOIKE Takayoshi Hokkaido Univ., Field Science Center, Prof., 北方生物圏フィールド科学センター, 教授 (10270919)
MARUYAMA Yutaka FFPRI Hokkaido, Head researcher, 北海道支所, 室長 (50343786)
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| Project Period (FY) |
1999 – 2001
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| Keywords | Elevated CO_2 / growth / physiology / wood structure / photosynthesis / acclimation / Larix / Betula |
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| Research Abstract |
We estimated long-term effects of elevated carbon dioxide concentrations [CO_2] on physiological and anatomical characteristics of trees, namely the stem growth, wood structure and characteristics of photosynthesis. Seedlings of larch (Larix sibirica and Larix kaempferi) and white birch (Betula platyphylla var. japonica) trees were grown in growth chambers under two [CO_2], ambient (360 ppm) and elevated (720 ppm), and with high or low levels of nutrients for one-three growing seasons. Elevated [CO_2] had no significant effects on stem height and stem diameter. However, the stem height and stem diameter were enhanced by the high level of nutrients and these increases were stimulated by elevated [CO_2]. Annual ring widths, cell numbers and cell diameters tended to increase, whereas cell wall thickness tended to decrease slightly in response to elevated [CO_2] , By contrast, there were no statistically significant differences in the relative area of cell wall, which was closely related to specific gravity of wood, indicating that elevated [CO_2] had few effects of changes in wood quality. In conclusion, there is no obvious enhancement in the capacity of carbon fixation by elevated [CO_2]. However, changes in the temporal pattern of stem growth and in anatomical features of the stem would occur under elevated [CO_2]. Although net assimilation rate under which seedlings grew was higher in elevated [CO_2] than in ambient [CO_2], little enhancement of photosynthesis rate of whole crown under elevated [CO_2] was observed because of the smaller specific leaf area and the acclimation of photosynthetic characteristics of leaves to [CO_2] which seedling grew. Such acclimation of photosynthesis was closely related to the decrease in amounts of soluble proteins and Rubisco, which is a key enzyme of photosynthesis, in leaves.
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