不同光强对4种城市绿化树木生长的影响
Effects of Different Light Intensity on the Growth of Four Urban Greening Trees

本研究通过将供试植物置于5种光强条件下延时照明培养，模拟城市夜间景观灯照明环境，探究不同光强对4种城市绿化树木叶片结构、叶绿素、生长势和生物量的影响。结果表明，随着光强增加，4种植物的叶面积和比叶面积呈现先增加后降低的趋势，在250 lx光强处理下叶面积最大，在150~250 lx光强处理下比叶面积值最高；延时光照处理下，干物质含量均降低。在70~150 lx光强处理下，可以促进叶绿素合成，并且植株的树高生长量、当年生枝条生长量和生物量积累量均达到最大值；当光强高于150 lx时，随着光强增加叶绿素含量降低，引起植物的光抑制，植株的生长量和生物量积累受到抑制。
The effects of different light intensity on leaf structure, chlorophyll, growth potential and biomass of four urban greening trees were studied through the cultivation experiment of the tested plants under five light intensities to simulate the lighting environment of urban landscape lamp at night. The results showed that the leaf area and specific leaf area of four plants increased first and then decreased with the increase of light intensity. The leaf area was the largest under 250 lx treatment, and the specific leaf area was the highest under 150~250 lx treatment, and the content of dry matter decreased under delayed illumination. Chlorophyll synthesis was promoted, and the tree height growth, annual branch growth and biomass accumulation reached the maximum under the light intensity of 70~150 lx. When the light intensity was higher than 150 lx, the chlorophyll content decreased with the increase of light intensity, resulting in that the photo inhibition of plants, and the growth and biomass accumulation of plants were inhibited.