广州市不同环境屋顶自然生长的植物多样性分析

通过对广州市不同环境屋顶自然生长的植物进行广泛调查，共记录到维管植物49科109属128种，其中，在污染严重、中等和轻微的环境分别记录到21种、73种和111种。结果表明，植物种类的数量与环境受污染程度成反比，而与周围植物的多少成正比。对植物形态学及生态生物学特征的分析结果表明，屋顶自然生长的植物与地上自然生长的植物相比，植株较矮小，叶片较小，根系较发达，根冠比较大，这是屋顶植物长期适应屋顶特殊环境的结果。通过调查及分析，推荐12种有较好屋顶绿化潜力的植物。

Diversity of plant species naturally growing on the building roofs with different environmental conditions in Guangzhou city

An extensive investigation on the plant species naturally growing on the building roofs of Guangzhou city was conducted in 2003. We found 128 vascular plant species in total, which belong to 49 families and 108 genera. The habitat condition of these plants was distinguished into three types based on the degree of pollution. The results showed that more species occurred in less pol- luted roof environment. One hundred and eleven species were found in the slightly-polluted roofs, 73 in the moderately-polluted roofs, and 21 in the severely-polluted roofs. Our results also showed that the number of species lived in building roofs increased with the species richness of the nearby environment. Compared with the plants living on the ground, roof plants had shorter stems, smaller leaves, more and longer roots, and higher root-shoot ratios. It indicated that roof plants have developed a suite of morphological characteristics in order to adapt to the harsh environment. Based on the adaptive ability of these roof plants, 12 plant species were recommended as the prior choices for roof gardening in Guangzhou city.