Effect of Urbanization on Vegetation in Riparian Area: Plant Communities in Artificial and Semi-Natural Habitats

Yang Cao,Yosihiro Natuhara

doi:10.3390/su12010204

Abstract

Riparian areas are local hot spots of biodiversity that are vulnerable and easily degraded. Comparing plant communities in habitats with different degrees of urbanization may provide valuable information for the management and restoration of these vulnerable habitats. In this study, we explored the impact of urbanization on vegetation communities between artificial and semi-natural habitats within two rivers with different levels of development. We compared species richness, types of vegetation, and composition patterns of the plants in our study. In artificial habitats, the sites with relatively high levels of urbanization had the highest species richness, while in semi-natural habitats, the highest species richness was recorded in the less urbanized sites. Furthermore, every component of urbanization that contributed to the variation of species richness was examined in the current study. In artificial habitats, the proportion of impervious surface was the strongest predictor of the variation in species richness and was associated with the richness of alien, native, and riparian species. In semi-natural habitats, most of the richness of alien and native species were associated with the distance to the city center, and the number of riparian and ruderal species was significantly related to the proportion of impervious surface. Moreover, we found that a high level of urbanization was always associated with a large abundance of alien and ruderal species in both artificial and in semi-natural habitats. We recommend the methods of pair comparison of multiple rivers to analyze the impact of urbanization on plant species in riparian areas and have suggested various management actions for maintaining biodiversity and sustainability in riparian ecosystems.

Highlights

Riparian areas represent one of the most frequently found types of green area in the urban ecosystem
Results of generalized linear model (GLM) analyses revealed that in artificial habitats, the alien species richness was mainly affected by precipitation and proportion of impervious surface (Table 5)
The best explanation model for the variation of native species richness included the proportion of impervious surface and traffic density; no significant effects were shown within the variables

Summary

Introduction

Riparian areas represent one of the most frequently found types of green area in the urban ecosystem. With the possible exception of ecosystem services, riparian areas increase the aesthetic value of urban and agricultural regions and expand people’s opportunities for outdoor activities. These services are valuable in riparian areas of the world, where humans rely on these services for well-being [3]. Urbanization exerts intensive anthropogenic pressure on these areas These places are highly modified and affected by a large number of human activities [9,10]. Managing urbanization impacts has become a conservation priority worldwide, the maintenance of riparian areas is often ignored

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Results

Conclusion