城市绿地乡土树种对大气污染的适应性响应

为探究华南乡土树种对东莞市不同绿地类型的适应性，将14种华南乡土树种分别栽植于四种绿地类型：工业绿地、道路绿地、城市公园和植物园，研究乡土树种的生理生态变化。各类型绿地的大气监测结果表明，道路绿地的各项大气污染指标明显高于其他绿地；工业区绿地的总悬浮颗粒物和氮氧化物浓度比植物园高；城市公园的总悬浮颗粒物浓度明显高于植物园。14个树种的生理生态研究结果表明，不同植物在各种绿地环境中适应策略各异，且随着污染强度的增加，多数植物净光合速率（Pn）和气孔导度（Gs）之间的相关系数降低，且Pn与Gs之间的相关系数变化不一致。14种华南乡土树种中，深山含笑、樟树、山杜英、黄栀子、胡氏青冈、九节、格木、黄果厚壳桂和华润楠等9个树种在不同污染环境下均表现出不同程度的敏感性，红鳞蒲桃和越南山龙眼对各种环境污染都不敏感，红叶石楠、假鹰爪和枫香在不同的污染环境中表现各异。

Response of Native Tree Species Adapted to Air Pollution in Urban Green Land

In order to check the adaptability of 14 kinds native tree species of South China adapted to green land with different air pollution stress, the species were planted in 4 types green land and taken into physiology and ecology research. 4 types green land included botanical garden, park with more total suspended particulate than that in botanical garden, green land in industrial estate with more nitrogen oxides and total suspended particulate, green land of busy road, which is the most polluted land of the city. The result suggested that: the ways and the ability adapted to different types green land were not the same among the native tree species. With the pollution stress increasing, the correlation of the Pn with Gs in most native tree species decreased, and the change level of correlation coefficient was also different. Among them, 9 kinds native tree species including Michelia maudiae, Cinnamomum camphora, Elaeocarpus sylvestris, Gardenia jasminoides, Cyclobalanopsis hui, Psychotria asiatica, Erythrophleum fordii, Cryptocarya concinna and Machilus chinensis were sensitive to all the pollution stress, while Syzygium hancei and Helicia cochinchinensis were not. Photinia serrulata, Desmos chinensis and Liquidambar formosana were sensitive to some types pollution stress but not to the others.