Higher clonal integration in the facultative epiphytic fern Selliguea griffithiana growing in the forest canopy compared with the forest understorey.
Higher clonal integration in the facultative epiphytic fern Selliguea griffithiana growing in the forest canopy compared with the forest understorey.
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DOI：
10.1093/aob/mcv059
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发表时间：
2015-07
期刊：
影响因子：
4.2
通讯作者：
Hua-Zheng Lu;Wen-Yao Liu;F. Yu;L. Song;Xingliang Xu;Chuan-sheng Wu;Yu-long Zheng;Yang-Ping Li
中科院分区：
文献类型：
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作者：
Hua-Zheng Lu;Wen-Yao Liu;F. Yu;L. Song;Xingliang Xu;Chuan-sheng Wu;Yu-long Zheng;Yang-Ping Li
背景与目的克隆整合（克隆植物的相连分株之间的资源共享）的优势各不相同，并且在更紧张和/或更异质的生境中期望更高程度的整合。无性系兼性附生植物既存在于林冠（附生生境），也存在于林下（陆生生境）。由于环境条件，特别是水分和养分，更紧张和异质性的冠层比在林下，本研究假设，克隆整合是更重要的兼性附生植物在附生栖息地比在陆地栖息地。方法通过田间试验，研究了兼性附生根茎蕨Selligueagriffithiana（水龙骨科）在附生生境和陆生生境中根茎连接（连接与不连接，即有与没有克隆整合）对单分株存活和生长的影响。在另一个田间试验中，分别在附生和陆生生境中，采用10 × 10 cm（2）和20 × 20 cm（2）的小块试验区，研究了根茎连接对分株生长的影响。关键结果根茎切断显著降低了S.在这两个实验中，griffithiana。在附生生境中，根状茎切断对单分株存活率、分株数量和生长的影响大于陆生生境。结论克隆整合对兼性附生蕨类植物的生长发育有重要影响，且在林冠中的作用比林下更重要。因此，结果支持的假设，自然选择有利于基因型与更高程度的整合在更紧张和异质性的环境。
BACKGROUND AND AIMS The advantage of clonal integration (resource sharing between connected ramets of clonal plants) varies and a higher degree of integration is expected in more stressful and/or more heterogeneous habitats. Clonal facultative epiphytes occur in both forest canopies (epiphytic habitats) and forest understories (terrestrial habitats). Because environmental conditions, especially water and nutrients, are more stressful and heterogeneous in the canopy than in the understorey, this study hypothesizes that clonal integration is more important for facultative epiphytes in epiphytic habitats than in terrestrial habitats. METHODS In a field experiment, an examination was made of the effects of rhizome connection (connected vs. disconnected, i.e. with vs. without clonal integration) on survival and growth of single ramets, both young and old, of the facultative epiphytic rhizomatous fern Selliguea griffithiana (Polypodiaceae) in both epiphytic and terrestrial habitats. In another field experiment, the effects of rhizome connection on performance of ramets were tested in small (10 × 10 cm(2)) and large (20 × 20 cm(2)) plots in both epiphytic and terrestrial habitats. KEY RESULTS Rhizome disconnection significantly decreased survival and growth of S. griffithiana in both experiments. The effects of rhizome disconnection on survival of single ramets and on ramet number and growth in plots were greater in epiphytic habitats than in terrestrial habitats. CONCLUSIONS Clonal integration contributes greatly to performance of facultative epiphytic ferns, and the effects were more important in forest canopies than in forest understories. The results therefore support the hypothesis that natural selection favours genotypes with a higher degree of integration in more stressful and heterogeneous environments.