Zhou Lingyan, Liu Fude, Yang Wenjie, Liu Hong, Shao Hongbo, Wang Zhongsheng, An Shuqing
The Laboratory of Forest Ecology and Global Changes, School of Life Sciences, Nanjing University, Nanjing 210093, China.
The Laboratory of Forest Ecology and Global Changes, School of Life Sciences, Nanjing University, Nanjing 210093, China ; School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China.
ScientificWorldJournal. 2014;2014:681369. doi: 10.1155/2014/681369. Epub 2014 Jun 4.
Epiphylls widely colonize vascular leaves in moist tropical forests. Understanding the effects of epiphylls on leaf traits of host plants is critical for understanding ecological function of epiphylls. A study was conducted in a rain forest to investigate leaf traits of the host plants Photinia prunifolia colonized with epiphyllous liverworts and foliicolous lichens as well as those of uncolonized leaves. Our results found that the colonization of lichens significantly decreased leaf water content (LWC), chlorophyll (Chl) a and a + b content, and Chl a/b of P. prunifolia but increased Chl b content, while that of liverworts did not affect them as a whole. The variations of net photosynthetic rates (P n ) among host leaves colonized with different coverage of lichens before or after removal treatment (a treatment to remove epiphylls from leaf surface) were greater than that colonized with liverworts. The full cover of lichens induced an increase of light compensation point (LCP) by 21% and a decrease of light saturation point (LSP) by 54% for their host leaves, whereas that of liverworts displayed contrary effects. Compared with the colonization of liverworts, lichens exhibited more negative effects on the leaf traits of P. prunifolia in different stages of colonization. The results suggest that the responses of host leaf traits to epiphylls are affected by the epiphyllous groups and coverage, which are also crucial factors in assessing ecofunctions of epiphylls in tropical forests.
叶附生植物广泛分布于潮湿热带森林的维管植物叶片上。了解叶附生植物对宿主植物叶片性状的影响对于理解叶附生植物的生态功能至关重要。在一片雨林中进行了一项研究，以调查被叶附生地钱和叶生 lichens 定殖的宿主植物石楠叶石楠的叶片性状，以及未被定殖叶片的性状。我们的结果发现，lichen 的定殖显著降低了石楠叶石楠的叶片含水量（LWC）、叶绿素（Chl）a 和 a + b 含量以及 Chl a/b，但增加了 Chl b 含量，而地钱的定殖总体上对它们没有影响。在去除处理（从叶片表面去除叶附生植物的处理）前后，被不同覆盖度 lichens 定殖的宿主叶片之间的净光合速率（Pn）变化大于被地钱定殖的叶片。lichen 的完全覆盖使其宿主叶片的光补偿点（LCP）增加了 21%，光饱和点（LSP）降低了 54%，而地钱的覆盖则显示出相反的效果。与地钱的定殖相比，lichen 在定殖的不同阶段对石楠叶石楠的叶片性状表现出更多的负面影响。结果表明，宿主叶片性状对叶附生植物的响应受叶附生植物类群和覆盖度的影响，这也是评估热带森林中叶附生植物生态功能的关键因素。
