人工控制条件下9种园林植物叶功能性状对短期NO2污染的响应

叶功能性状能反映植物对环境变化的适应策略，利用开顶式熏气法，对9种常见园林植物进行为期20天的NO₂熏气实验，分析不同NO₂浓度熏气下叶片形态结构指标（单叶干重、单叶面积、比叶面积）、光合生理指标（光合速率、荧光参数）及化学性状指标（叶N含量、叶P含量、N：P比值）的差异，从而探讨以上植物叶性状对NO₂污染的短期响应。结果表明，不同植物叶性状对不同浓度NO₂污染的响应存在显著差异，即不同植物应对NO₂污染的适应策略不同，同种植物在不同浓度NO₂熏气下叶性状指标变化趋势相同，但变化幅度不同，可见同种植物对不同NO₂浓度的响应策略也存在差异；大部分叶性状指标间表现出显著的相关性，但叶N含量与比叶面积间未发现显著相关性，表明叶经济谱性状间权衡机制的稳定性在个体尺度上可能会发生改变。研究结果揭示了不同植物对NO₂污染的适应与响应差异，对预测城市NO₂污染可能带来的植物功能性状的协同进化以及植物生态策略的改变具有重要意义。

The impact of short-term NO2 pollution on leaf functional traits of nine landscape plant species

Leaf functional traits can reflect adaptation and response of individual plants to environmental variability. In this study, we conducted a 20-day artificial fumigation experiment on nine common landscape plant species to examine the response of leaf morphological traits (individual leaf mass, individual leaf area, and specific leaf area), photosynthetic traits (photosynthetic rate and fluorescence parameters), and chemical traits (leaf nitrogen content, leaf phosphorus content, and N:P ratio) to different NO₂ concentration treatments. The experiments showed there were significant differences in the response of different plant leaf traits to NO₂ pollution, notably that different plants had different adaptation strategies to deal with NO₂ pollution. Leaf traits of the same plant under different concentrations of NO₂ varied in the same direction, but were of different magnitudes, which means the response strategy of the same plant to different NO₂ concentrations also varied. We found that most leaf trait relationships were consistent with the leaf economic spectrum. However, there was no significant correlation between leaf nitrogen content and specific leaf area (SLA). The lack of a significant leaf N-SLA relationship might be caused by the variations in environmental conditions. Our research revealed plant differences in response to NO₂ pollution, and these results are of great significance for predicting coevolution of plant functional traits and changes in plant ecological strategies brought about by urban air pollution.