城市绿地生态保护视角昆虫光谱趋性差异

照明提升城市夜间安全与活力,是城市建设的重要因素。但近年来夜间照明的迅速蔓延,改变了城市自然环境的光周期与光分布范围,造成光污染生态风险。其中,趋光昆虫受到的胁迫尤为显著,城市绿地昆虫种类与数量急剧下降,进而通过级联效应,引发城市绿地生态系统失衡问题。昆虫是典型的生态指示种和光敏动物,明确昆虫的光谱趋性差异,筛选出对昆虫趋光性友好的光谱,可为生态光源的研发提供依据,从而降低城市照明的生态风险。已有研究较多采用实验室内实验箱的设置方法,探究某一特定昆虫属种的趋光行为,尚缺乏对特定生境下的昆虫群落和典型昆虫目的光谱趋性研究。因此,研究在天津市津南区天津大学北洋园校区绿地系统开展野外人工光诱捕昆虫实验,以野外诱捕昆虫的种类与数量为判定依据,分析各光谱的昆虫趋性差异。野外诱虫实验以7种窄光带光谱(单色光)为研究对象,采用相对评价法,设置趋光昆虫最敏感的紫外光(Ultraviolet,369 nm)为对照组。结果表明,天津城市绿地生境中,4类典型趋光昆虫为双翅目(61.1%)、半翅目(19.7%)、鞘翅目(11.1%)、鳞翅目(5.7%)类,占诱捕总量的97.6%;对照紫外光(Ultraviolet,369 nm),4种典型昆虫总体的趋性敏感光谱排序及趋性概率为:远红色光(Far Red,740 nm)0.5%＜深红色光(Deep Red,660 nm)2.0%＜橘红色光(Red Orange,627 nm)9.0%＜青色光(Cyan,500 nm)22.8%＜绿色光(Green,519 nm)22.9%＜蓝紫色光(Royal Blue,447 nm)27.6%＜蓝色光(Blue,478 nm)40.1%;绝对生态光谱为红光,相对生态光谱为青色光(Cyan,500 nm)和蓝紫色光(Royal Blue,447 nm)。在全面推进人与自然和谐共生的现代化建设阶段,研究将有助于生态光源的开发、生态保护和城市光生态建设的提升。

Differences in insect spectral tropism from the perspective of urban green space ecological protection

Lighting enhances the safety and vitality of the city at night and is an important factor in urban construction. However, in recent years, the rapid spread of night lighting has changed the photoperiod and light distribution range of the urban natural environment, causing the ecological risk of light pollution. Among them, phototaxis insects are particularly stressed, and the species and number of insects in urban green space decrease sharply, which leads to the imbalance of urban green space ecosystem through cascading effects. Insects are typical ecological indicator species and photosensitive animals. Clarifying the difference of spectral taxis of insects and screening out the spectrum friendly to insect phototaxis can provide a basis for the research and development of ecological light sources, so as to reduce the ecological risk of urban lighting. Many studies have used the setting method of laboratory chamber to explore the phototaxis of a specific insect species, but there is a lack of spectral taxis of insect communities and typical insect targets in specific habitats. Therefore, this study carried out field experiments on artificial light trapping of insects in the green space system of Tianjin University Beiyangyuan Campus, Jinnan District, Tianjin, and analyzed the differences of insect taxis in various spectra based on the species and quantity of insects trapped in the field.In the field insect trapping experiment, seven kinds of narrow band light (monochromatic light) were used as the research object, and Ultraviolet light (369 nm), the most sensitive light of phototropic insects, was set as the control group by relative evaluation method. The results showed that the four typical phototropic insects were Diptera (61.1%), Hemiptera (19.7%), Coleoptera (11.1%) and Lepidoptera (5.7%), accounting for 97.6% of the total trapping. Compared with Ultraviolet (369 nm), the overall taxotaxis sensitivity spectrum ordering and taxotaxis probability of the four typical insects are as follows: Far Red light (Far Red, 740 nm) 0.5%