Light compensation points in shade-grown seedlings of deciduous broadleaf tree species with different successional traits raised under elevated CO2
Light compensation points in shade-grown seedlings of deciduous broadleaf tree species with different successional traits raised under elevated CO2
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DOI：
10.1111/plb.12400
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发表时间：
2016-01-01
期刊：
影响因子：
3.9
通讯作者：
Koike, T.
中科院分区：
文献类型：
--
作者：
Kitao, M.;Hida, T.;Koike, T.
为了研究CO2浓度升高对不同演替性状的落叶阔叶树遮荫性的影响，对4种日本北部原生树种遮荫幼苗进行了叶片光合特性的测定。我们认为白桦（Betula platyphylla var. japonica）和白桦（Betula maximmowicziana）是先锋种，蒙古栎（Quercus mongolica var. crispula）是中期演替种，单槭（Acer mono）是顶极种。这些植物生长在遮荫条件下（10%的充分日照），在二氧化碳调节的植物园内。当二氧化碳浓度升高（720 μ mol / l）时，所有树种的光补偿点（lcp）均下降。Mol(-1))，表观量子产率较高，但没有光合作用下调。在高CO2条件下生长的蒙古松和单根白桦的lcp低于两个先锋桦树种。不同CO2处理下，蒙古栎幼苗的LCP与白栎幼苗的LCP无显著差异。然而，单根柽柳的暗呼吸速率比蒙古栎低，这表明单根柽柳作为顶极物种在夜间的碳损失方面具有更高的遮荫耐受性。因此，CO2升高可能通过降低lcp而增强了所有物种的遮荫耐受性，但与演替性状相关的遮荫耐受性排序在CO2升高的物种中没有变化，即顶极物种（a . mono）的遮荫耐受性最高，其次是间隙依赖物种（Q. mongolica），而先驱物种（B. platyphylla和B. maximowicziana）的遮荫耐受性较低。
We measured leaf photosynthetic traits in shade-grown seedlings of four tree species native to northern Japan, raised under an elevated CO2 condition, to investigate the effects of elevated CO2 on shade tolerance of deciduous broadleaf tree species with different successional traits. We considered Betula platyphylla var. japonica and Betula maximowicziana as pioneer species, Quercus mongolica var. crispula as a mid-successional species, and Acer mono as a climax species. The plants were grown under shade conditions (10% of full sunlight) in a CO2-regulated phytotron. Light compensation points (LCPs) decreased in all tree species when grown under elevated CO2 (720 mu mol . mol(-1)), which were accompanied by higher apparent quantum yields but no photosynthetic down-regulation. LCPs in Q. mongolica and A. mono grown under elevated CO2 were lower than those in the two pioneer birch species. The LCP in Q. mongolica seedlings was not different from that of A. mono in each CO2 treatment. However, lower dark respiration rates were observed in A. mono than in Q. mongolica, suggesting higher shade tolerance in A. mono as a climax species in relation to carbon loss at night. Thus, elevated CO2 may have enhanced shade tolerance by lowering LCPs in all species, but the ranking of shade tolerance related to successional traits did not change among species under elevated CO2, i.e. the highest shade tolerance was observed in the climax species (A. mono), followed by a gap-dependent species (Q. mongolica), while lower shade tolerance was observed in the pioneer species (B. platyphylla and B. maximowicziana).