Urban biodiversity in China: Who are winners? Who are losers?

Abstract

Rapid urbanization in the last three decades has impacted biogeographic patterns of wildlife in China profoundly. Large areas of natural habitats have been converted into concentrated industrial and residential areas [1]. Remaining habitats in vicinities of cities are often fragmented and degraded [2]. Besides land use/land cover changes, anthropogenic disturbances such as the introduction of exotic species further add pressure on local biodiversity [3]. How does wildlife respond to these impacts? Who will win and who will lose in this urbanization process in China? Answers to these questions will help conservation agencies to manage the impacts of urbanization on biodiversity more effectively. A general finding from urban biodiversity studies is that urbanization favors exotic species over native species because of the environmental filtering effect and anthropogenic influences [3]. The temporal change of species composition of birds in Beijing serves as a good example. By comparing the species composition of birds in Beijing recorded during 1954–1978 [4, 5] to those recorded during 2003–2013 (Chinese Bird Reports, http://www.chinabirdnet. org/report.html; eBird, http://www.ebird.org/), one can find that the proportion of species whose distribution ranges are outside of Beijing increased significantly, up from 22 % of the 172 observed species to 46 % of the 409 observed species. Three species whose distribution ranges encompass Beijing could not be observed in the later time (Names of species listed in supplementary Table S1). The gain of exotic species and loss of native species cause biotic homogenization, which is considered one of the most prominent forms of biotic impoverishment worldwide [6]. The diversity pattern of urban woody plants in China bears the evidence of this trend. Assemblages of urban woody plants from 35 Chinese cities had lower dissimilarities of species composition between urban areas than these of woody plants in natural areas (Fig. 1a, b, paired t test, P 0.001), which indicated that urbanization had a homogenization effect. This effect was significant and detectable as social factors explained 11 % of variation in the composition dissimilarity (Fig. 1c). Species from families like Prunus, Populus, and Magnolia have contributed to the homogenization of urban woody plants, which may be due to their wide use in landscaping. That rapid urbanization in China has caused negative impacts on urban biodiversity is supported bymore andmore evidences. The question is: ‘‘Why bother?’’ China has the largest urban population in the world—670 million and an additional 100million by 2020 is expected [7].Many of them experience ‘‘nature’’ primarily in urban areas. Preservation of urban biodiversity will increase their awareness to the importance of biodiversity conservation in nature [8]. Values of urban biodiversity are not restrict to psychological and educational benefits. Urban biodiversity is the foundation of a healthy urban ecosystem. Preserving biodiversity in urban ecosystems can sustain the supply of much-needed Electronic supplementary material The online version of this article (doi:10.1007/s11434-016-1187-7) contains supplementary material, which is available to authorized users.