Morphological and physiological responses of Siebold's beech (Fagus crenata) seedlings grown under CO2 concentrations ranging from pre-industrial to expected future levels
Morphological and physiological responses of Siebold's beech (Fagus crenata) seedlings grown under CO2 concentrations ranging from pre-industrial to expected future levels
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DOI：
10.1007/s11355-011-0149-0
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发表时间：
2012-01-01
影响因子：
2
通讯作者：
Koike, Takayoshi
中科院分区：
文献类型：
--
作者：
Hirano, Atsushi;Hongo, Ichiro;Koike, Takayoshi
毛毛榉（学名：Fagus crenata）是日本寒温带森林中的一种常见树种。由于天然更新的山毛榉林预计将有助于在未来的森林保护，我们调查了不同的CO2浓度（[CO2]）对山毛榉幼苗的生长形态和生理变化的影响。橡子收集的山毛榉林在Minakami，日本中部的发芽和生长在第一个生长季节6个月下四个[CO2]水平（200，350，550，和750亩L-1）。茎质量随着[CO2]的增加而增加;然而，根质量在处理之间没有显著变化。随着CO2浓度的增加，净光合速率（P（n））和叶面积增加，而蒸腾速率（T（r））、气孔导度、叶绿素含量和叶片寿命下降。虽然水利用效率（WUE;即，P（n）/T（r）随CO2浓度的增加而增加，气孔密度变化不显著。随着CO2浓度的增加，顶芽数和顶芽长度增加，表明下一季新枝叶形成加快。在较高的环境[CO2]水平下生长的山毛榉树苗，预计在未来的增强WUE水平可能有利于他们的生存，考虑到山毛榉树苗更喜欢中温条件。
Siebold's beech (Fagus crenata) is a common species in the cool temperate forests of Japan. As the natural regeneration of beech forests is expected to contribute to forest conservation in the future, we investigated the effects of different CO2 concentrations ([CO2]) on the growth of beech seedlings in relation to morphological and physiological changes. Acorns collected from beech forest in Minakami, central Japan were germinated and grown during a first growing season of 6 months under four [CO2] levels (200, 350, 550, and 750 mu L L-1). Stem mass increased with increasing [CO2]; however, root mass did not change significantly among the treatments. As [CO2] increased, net photosynthetic rate (P (n)) and leaf area increased, whereas transpiration (T (r)), stomatal conductance, leaf chlorophyll content, and leaf longevity decreased. Although water-use efficiency (WUE; i.e., P (n)/T (r)) improved with increasing [CO2], the density of stomata did not significantly change. Increases in the number of buds and the terminal bud length with increasing [CO2] indicated accelerated formation of additional branches and leaves in the next season. The enhanced WUE levels seen in beech saplings growing under the higher environmental [CO2] levels that are expected in the future may be advantageous for their survival, considering that beech saplings prefer mesic conditions.