Biodiversity conservation in a fast-growing metropolitan area in China: a case study of plant diversity in Beijing

Abstract

As the capital of China, Beijing has experienced extensive urbanization in the past two decades. To explore the effect of urbanization on plant diversity, we investigated the vascular plant diversity of the whole Beijing Municipality in three different functional (urban, suburban and exurban) regions. For its geo-diversity, Beijing has a rather abundant vascular plant diversity (2,276 species), including 207 species of conservation concern such as endemic, threatened and protected species. The exurban region had not only the highest species diversity (1,998 species), but also the most species of conservation concern (194 species). Urban region possessed the maximum alien species in terms of both absolute number and proportional representation, while the suburban region had the least species diversity (1,026 species). Some problems, such as wetland shrink and biological invasions, were common in the whole Beijing Municipality. However, primary threats to biodiversity differed in the three functional regions. The urban and suburban regions mainly suffered from habitat loss and fragmentation due to urban sprawl, while the exurban region faced serious ecosystem degradation from increasing disturbance from both local and urban people. Based on our investigation, we put forward conservation strategies for the three regions: improving the structure and ecological function of green spaces in urban region, preserving as much remnant natural habitats in the suburban region, and restricting the rural tourism and establishing a biosphere reserve in the exurban region. In addition,

Plant species composition in green spaces within the built-up areas of Beijing, China

“…Alien species in the built-up areas of Beijing accounted for 53% of all species recorded in our survey. While this percentage is close to the 54.8% of alien plant species reported by Wang et al (2007), it is much larger than the 28.6% that were recorded by Zheng and Liu (2006), a study conducted in the constructed urban areas of Beijing. It is also greater than the range of 19.3-45.7% that was found in a study of eight cities in the eastern and mid-western United States, including New York City (Clemants and Moore 2003).…”

“…While Polish villages have an average of 30% nonnative plant species, medium-sized towns have an average of 40-50%, and cities have an average of 50-70% non-natives (Kowarik 1990). Thirty three invasive species were recorded in this study, including four harmful invasive species that were previously reported in another study on the urban flora of Beijing (Wang et al 2007). These were Alternanthera philoxeroides, Conyza canadensis, Galinsoga parritlora, and Lolium temulentum.…”

“…A large proportion of native species found in the mountain areas do not occur in the built-up urban environments, where the plant species have been mostly planted since 1949 (Wang et al 2007). Therefore, while not all those mountain species are capable of growing in an urban environment, there is still great potential to increase the diversity of native plant species in the central built-up areas of Beijing.…”

Disturbance impacts of land use change on biodiversity conservation priority areas across China: 1990–2010

“…From 2000-2010, the increase of the built-up land area in East China was about 2.55 times the increase from 1990 to 2000. It is notable that the expanded area of built-up land with less vegetation distribution was mainly converted from semi-natural cropland, thus exerting considerable pressure on biodiversity conservation (Li et al, 2010;McDonald et al, 2008;Seto et al, 2012;Wang et al, 2007). Cropland reclamation mostly occurred in Northeast and Northwest China.…”

“…Accordingly, they have suggested that increased efforts should be made to protect Mediterranean-type forests and scrublands, as well as traditional agricultural practices. Wang et al (2007) analyzed the vascular plant diversity of Beijing along an urban-suburban-rural gradient, and recommended improving the structure and ecological function of green spaces in urban region, preserving as much remnant natural habitats in the suburban region, and restricting the rural tourism and establishing a biosphere reserve in the exurban region. Newmark et al (2011) conducted a multispecies analysis of the impact of habitat fragmentation on avian nest survival within an Afrotropical understory bird community.…”