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作 者 ：骆土寿,李意德,陈德祥,陈步峰,林明献

期 刊 ：生态学报 2003年 23卷 9期 页码：1765~1772

关键词：气体交换；光合环境；优势树种；热带雨林；

Keywords:leaf gas exchange, photosynthetic environment, dominant tree species, tropical rain forest,

摘 要 ：用Li-6400便携式光合测定系统(Li-CorInc.,USA)对海南岛热带山地雨林恢复演替先锋建群种黄桐(EndospermumchinenseBenth.)叶片的气体交换特征及其对环境的响应进行了测定。结果表明:(1)净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(E)日变化均为双峰型曲线。出现"午睡"原因是光合有效辐射(PPFD)不足和Gs的关闭,不是强光抑制和水分胁迫。(2)叶片Pn大小与Gs、E、PPFD、气温(Ta)和叶面温度(Tl)等为密切的正比关系,与胞间CO2浓度(Ci)、大气CO2浓度(Ca)和大气相对湿度(RH)等相关度极低甚至是负相关,光饱和点(LSP)较高,表现出阳性树种特性。(3)短期高Ca作用会引起Gs、E的降低和Pn增高。Ca倍增,则Pn提高了70%,E降低4.43%,水分利用效率(WUE)提高78%。(4)叶片Pn日平均值和日最大值分别达6.40±0.17、11.60μmolCO2/(m2·s),表现出速生性。

Abstract:To investigate how will leaf gas change of species response to environmental factors during the succession of tropical regeneration forest, we choose the dominant tree species, Endospermum chinense Benth as our study case. Leaf gas change characteristics and its responses were measured with Li 6400 portable photosynthesis system (Li Cor Inc.,USA) in Jianfengling, Hainan Island. Netphotosynthesis, stomatal conductance and transpiration are all exhibited a bimodal diurnal pattern and the first peak is reach...

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