Wang Wei, Franklin Scott B, Lu Zhijun, Rude Brian J
Analytic Consulting Group, Epsilon Blue Ash, OH, USA.
School of Biological Sciences, University of Northern Colorado Greeley, CO USA.
Front Plant Sci. 2016 Feb 16;7:151. doi: 10.3389/fpls.2016.00151. eCollection 2016.
Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a 5-year period (2003-2007) after a mast flowering event (2003). We examined flowering culm and seedling characteristics in relation to questions regarding the evolution of delayed flowering. Density of live culms decreased over the 5 years in both flowering sites and un-flowered patches. New shoots regenerated only in un-flowered patches. Chemical constituent allocation varied among culm parts (stems, branches, and leaves). Crude protein and extract ether in branches and leaves were less in flowering culms than in un-flowered culms. Seedling density was lower than expected based on floret counts, suggesting predation of seeds. Seedling density was significantly greater in flowering sites than in un-flowered patches and decreased over time. Seedlings performed better in flowering sites than in un-flowered patches based on their height, leaf number per seedling, and average leaf length, while fertilization on flowering sites had no significant effect on seedling growth, suggesting a saturation of resources. This study suggested that the characteristics of bamboos and bamboo stands were dramatically altered during this flowering event, enhancing seedling establishment and growth, and supporting mostly the habitat modification hypothesis of delayed reproduction.
竹种的集体开花会影响生态系统特性和保护工作，但记录这些周期性事件却很困难。在此，我们比较了中国秦岭地区一种箭竹（秦岭箭竹）在一次大规模开花事件（2003年）后的5年期间（2003 - 2007年）开花区域和未开花区域的特征。我们研究了开花竹茎和幼苗的特征，以探讨延迟开花的进化问题。在这5年里，开花区域和未开花区域的活竹茎密度均有所下降。新笋仅在未开花区域再生。竹茎各部分（茎、枝和叶）的化学成分分配有所不同。开花竹茎的枝叶中的粗蛋白和乙醚提取物含量低于未开花竹茎。基于小花数量，幼苗密度低于预期，这表明种子存在被捕食的情况。开花区域的幼苗密度显著高于未开花区域，且随时间下降。基于幼苗高度、单株叶片数量和平均叶长，幼苗在开花区域的表现优于未开花区域，而在开花区域施肥对幼苗生长没有显著影响，这表明资源已饱和。这项研究表明，在这次开花事件期间，竹子和竹林的特征发生了显著变化，促进了幼苗的建立和生长，并且主要支持延迟繁殖的栖息地改变假说。
