Nikko Botanical Garden, Graduate School of Science, The University of Tokyo, 321-1435 Tochigi, Japan.
Graduate School of Life Sciences, Tohoku University, Aoba, Sendai, 980-8578 Miyagi, Japan.
New Phytol. 2012 Sep;195(4):803-811. doi: 10.1111/j.1469-8137.2012.04218.x. Epub 2012 Jul 6.
In crowded stands, height is often similar among dominant plants, as plants adjust their height to that of their neighbours (height convergence). We investigated which of the factors, light quality, light quantity and mechanical stimuli, is primarily responsible for stem elongation and height convergence in crowded stands. We established stands of potted Chenopodium album plants. In one stand, target plants were surrounded by artificial plants that were painted black to ensure that the light quality was not modified by their neighbours. In a second stand, target plants were surrounded by real plants. In both stands, one-half of the target plants were anchored to stakes to prevent flexing by wind. The target plants were lifted or lowered by 10 cm to test whether height convergence was affected by the different treatments. Stem length was affected by being surrounded by artificial plants, anchoring and pot elevation, indicating that light quality, light quantity and mechanical stimuli all influenced stem elongation. Height convergence did not occur in the stand with artificial plants or in anchored plants. We conclude that light quality and mechanical stimuli are important factors for the regulation of stem growth and height convergence in crowded stands.
在拥挤的看台中，优势植物的高度通常相似，因为植物会根据邻居的高度调整自己的高度（高度趋同）。我们研究了哪些因素，如光质、光量和机械刺激，是导致拥挤的看台中茎伸长和高度趋同的主要原因。我们建立了盆栽藜属植物的看台。在一个看台中，目标植物被涂成黑色的人工植物包围，以确保光质不会被邻居改变。在第二个看台中，目标植物被真正的植物包围。在两个看台中，一半的目标植物被固定在桩上，以防止被风吹弯。目标植物被抬高或降低 10 厘米，以测试高度趋同是否受到不同处理的影响。茎长受到被人工植物包围、固定和花盆抬高的影响，这表明光质、光量和机械刺激都会影响茎的伸长。在有人工植物或固定植物的看台中，没有发生高度趋同。我们得出结论，光质和机械刺激是调节拥挤看台中茎生长和高度趋同的重要因素。
