Trait acclimation of the clonal fern Selliguea griffithiana to forest epiphytic and terrestrial habitats
Trait acclimation of the clonal fern Selliguea griffithiana to forest epiphytic and terrestrial habitats
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DOI：
10.1111/1440-1703.12002
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发表时间：
2019-05
影响因子：
2
通讯作者：
Quan Chen;Jingjue Sun;L. Song;Wen-Yao Liu;F. Yu;Su Li;H. Gong;Hua-Zheng Lu
中科院分区：
文献类型：
--
作者：
Quan Chen;Jingjue Sun;L. Song;Wen-Yao Liu;F. Yu;Su Li;H. Gong;Hua-Zheng Lu
尽管附生生境比陆地生境更具压力和异质性，但兼性附生植物如何适应这种截然不同的环境却知之甚少。我们的研究重点是Selliguea griffithiana附生个体和陆生个体之间功能性状的变化，并提供了该物种对这种对比环境的相当大的功能适应。我们从中国西南部亚热带山地潮湿森林的附生和陆地生境中采集了 S. griffithiana 的分株。对S. griffithiana的形态和解剖性状、光合作用、生物量和分株密度进行了测量，发现这些性状在两个生境之间存在显着差异。附生生境的叶长、叶柄长度、间隔长度（分株间距离）、气孔密度、叶脉密度、最大叶绿素荧光和叶绿素相对含量以及每分株生物量均低于陆生生境，而附生生境的叶厚度和分株密度则较高。光合光响应曲线显示陆地生境个体比附生生境个体具有更高的碳同化能力，而累积失水曲线显示后者的失水率较低。研究结果表明，S. griffithiana 对这两种栖息地都有适应，也就是说，附生分株可以以降低光合能力为代价缓解水资源短缺，而陆生分株可以在没有任何水分胁迫的情况下提高光捕获能力，达到更高的光合能力。
Although epiphytic habitats are more stressful and heterogeneous than terrestrial habitats, how facultative epiphytes acclimate to such contrasting environments has been poorly understood. Our study focused on the variation of functional traits between epiphytic and terrestrial individuals of Selliguea griffithiana, and provided considerable functional acclimation of this species to such contrasting environments. We sampled ramets of S. griffithiana from epiphytic and terrestrial habitats of a subtropical montane moist forest, SW China. Morphological and anatomical traits, photosynthesis, biomass and ramet density of S. griffithiana were measured and it was found that these traits differed significantly between the two habitats. Frond length, stipe length, spacer length (interramet distance), stomatal density, vein density, maximal chlorophyll fluorescence and relative chlorophyll content of fronds, and biomass per ramet were all lower in epiphytic habitat than those in terrestrial habitat, whereas frond thickness and ramet density were higher in the former. Photosynthetic light-response curves revealed a higher carbon assimilation capability of individuals in terrestrial habitat than in epiphytic habitat, whereas cumulative water loss curves showed a lower water loss rate in the latter. The findings demonstrate acclimation of S. griffithiana to both habitats, that is, epiphytic ramets can mitigate water scarcity at some cost of a reduced photosynthetic capacity, whereas terrestrial ramets can afford to improve the light capture to a higher photosynthetic capacity without any water stresses.