Response of spontaneous plant communities to microhabitats in a riparian corridor in Beijing, China.

With the increasing urban environmental problems, spontaneous vegetation has been gradually emphasized for high ecological value, whose distribution has been reported as strongly influenced by fine-scale environmental factors. As one of the major zones for urban spontaneous vegetation distribution, urban riparian corridors are well suited for research on the response of spontaneous plants to microhabitats. Taking the Wenyu River-North Canal in Beijing as the study site, we measured six microhabitat factors, including the level of maintenance and visitor activity, canopy density, litter thickness, and distance to water and road, to investigate their effects on spontaneous plant assemblages. The results showed that spontaneous plants respond significantly to fine-scale habitat variation, and were more responsive to human disturbance than other factors. Compared with diversity indicators, the functional trait compositions were more significantly correlated with microhabitat factors. Under lower maintenance of plants, the spontaneous communities had a higher invasion risk for plants. Thick litter can impede the occurrence of invasive species while favoring the growth of native ones. Our findings are important for furthering understanding of the spontaneous plant community establishment, and can serve as a good reference for the maintenance and management of spontaneous plants in urban riparian corridors.