Photosynthetic characteristics and light energy conversions under different light environments in five tree species occupying dominant status at different stages of subtropical forest succession.
Photosynthetic characteristics and light energy conversions under different light environments in five tree species occupying dominant status at different stages of subtropical forest succession.
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DOI：
10.1071/fp14355
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
Qiang Zhang;Tai-Jie Zhang;W. Chow;Xin Xie;Yuan-Jun Chen;C. Peng
中科院分区：
文献类型：
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作者：
Qiang Zhang;Tai-Jie Zhang;W. Chow;Xin Xie;Yuan-Jun Chen;C. Peng
为了揭示亚热带森林光梯度演替机制，研究了马尾松（Pinus massoniana Lamb）等5种树种对3种光环境的光合生理响应。，两个中期演替种木荷。等冠军。和Castanopsis fissa (Champ。Benth交货)。Rehd。会。晚演替种Cryptocarya concinna Hance。和尖锐湿疣（BI）。Merr et Perry)，选自华南鼎湖山亚热带森林。结果表明，在100%、30%和12%全光照条件下，先行者种的光合能力（Amax）、光饱和点（LSP）、羧化效率（CE）和磷酸三糖利用率（TPU）最高，具有较强的光合能力和较高的二氧化碳吸收效率。然而，较高的光补偿点（LCP）和暗呼吸（Rd）以及较低的表观量子产率（AQY）表明先锋种不能适应弱光条件。中期演替物种的光合特性介于先行者和后期演替物种之间，但PSII的有效量子产率（ΦPSII）和光利用效率（LUE，以光合作用表示）最大。与先驱者和中期演替物种相比，晚期演替物种的光合能力和碳吸收效率较低，但具有较高的遮荫耐受性和强光散热能力，其特征是黄叶素循环总色素（VAZ）水平较高，黄叶素循环去环氧化状态（DEPs）较高。这些结果表明，光合能力沿演替轴递减，演替后期物种有较强的热耗散能力来补偿其较弱的光合能力。
In order to reveal the mechanism of succession in subtropical forest along a light gradient, we investigated photosynthetic physiological responses to three light environments in five tree species including a pioneer species Pinus massoniana Lamb., two mid-successional species Schima superba Gardn. et Champ. and Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils., and two late-successional species Cryptocarya concinna Hance. and Acmena acuminatissima (BI.) Merr et Perry) that were selected from Dinghu Mountain subtropical forest, South China. Results showed that, among the three kinds of species in all light conditions (100%, 30% and 12% of full sunlight), the pioneer species had the highest photosynthetic capacity (Amax), light saturation point (LSP), carboxylation efficiency (CE) and maximum utilisation rate of triose phosphate (TPU) that characterised a strong photosynthetic capacity and high carbon dioxide uptake efficiency. However, a higher light compensation point (LCP) and dark respiration (Rd) as well as lower apparent quantum yield (AQY) indicated that the pioneer specie cannot adapt to low light conditions. Mid-successional species had photosynthetic characteristics in between pioneer and late-successional species, but had the greatest effective quantum yield of PSII (ΦPSII) and light use efficiency (LUE, expressed in terms of photosynthesis). In contrast to pioneer and mid-successional species, late-successional species had lower photosynthetic capacity and carbon uptake efficiency, but higher shade tolerance and high-light heat dissipation capacity, as characterised by higher levels of total xanthophyll cycle pigments (VAZ) and de-epoxidation state of xanthophyll cycle (DEPs). These results indicate that photosynthetic capacity decreases along the successional axis and that late-successional species have more responsive heat dissipation capability to compensate for their inferior photosynthetic capacity.