Diversity and influencing factors on spontaneous plant distribution in Beijing Olympic Forest Park

With intensive management practices on highly cultivated urban vegetation resulting in the over-consumption of natural resources and urban green spaces losing ecological function, interest is growing in spontaneous plants. Our goal was to improve knowledge of the biodiversity and distribution patterns of spontaneous vegetation in urban parks, which may benefit sustainable and low-maintenance planting design in future green spaces. To disentangle these patterns, a field survey was carried out at both habitat (determined by position in the park) and microhabitat (determined by the planted plants) scales. A total of 102 spontaneous plant species were recorded, and most of them were herbaceous plants. The habitats located between road and building (R-B) and waterside (WS) showed maximum levels of diversity and evenness; the two microhabitats showing maximum levels of diversity and evenness were the waterside unplanted plot (WUP) and the flower bed (FB). Microhabitat affected spontaneous plants more significantly than did habitat. Furthermore, canopy density (CD) and intensity of disturbance (ID) were influencing factors at both scales, while community structure of planted plants (P-CS) was only influential at the habitat scale and slope gradient (SG) was influential at the microhabitat scale. Additionally, the impact of specific planted trees was not significant, but some associated species were notable. Species composition showed markedly different characteristics in different habitats and microhabitats. Understanding these patterns and influencing factors could provide helpful references for any future construction of sustainable urban vegetation with low-maintenance, high-biodiversity and local character.