不同城市化梯度对北京绿地植物群落的影响

Effect of urbanization in Beijing City on plant communities

城市化对生物多样性的影响是目前城市生态学的一项重要研究内容。本研究按照北京城市发展梯度,对北京城区六环内公园、居民区和道路3类绿地类型中的植物群落进行踏查和样方调查,分析植物物种组成及多样性对城市化的响应。结果表明:1)在北京城区六环内共调查到103科319属536种植物,其中,多种科有菊科、蔷薇科、禾本科和豆科等,多种属有李属(Prunus)和蒿属(Artemisia)等;2)国外引进种有80种,占总物种数的14.9%,国内引进种有95种,占总物种数的17.7%,本地物种数有361种,占总物种数的67.4%;3)城市绿地植物中乔木和灌木的物种丰富度及物种多样性随着城市化梯度的递增呈现出先下降后上升的趋势,而草本的变化不明显;植物物种均匀度随着城市化梯度的增加无明显的变化规律,物种同质化严重。

The effects of urbanization on biodiversity is an important field in urban ecology. We investigated plant communities in three green-land types, parks, residential areas, and roads along an urbanization gradient in the Beijing urban area (inner 6th ring road). Species composition, similarity index, and diversity of plants in urban areas were calculated. The results showed 536 species, belonging to 103 families, and 319 genera in the Beijing urban area. Among them, there were 361 native species and 175 imported species. 80 species were imported from abroad and 95 species from inland, namely 14.9% and 17.7% of the total species, respectively. The species richness and diversity of trees and shrubs first increased and then decreased along the urbanization gradients, with the decreasing trend from the inner 2nd ring road and the increasing trend from the 3rd – 4th ring road. No significant difference was found along the urbanization gradient for herbaceous plants. There were no significant differences in species evenness along the urbanization gradient.