In the foreseeable future, global urbanization will continue to develop in a rapid way. A better understanding of the relationship between degree of urbanization and biodiversity becomes more important for urban planning and conservation of species diversity.

Prof. Runzhi Zhang’s research group, from Institute of Zoology, Chinese Academy of Sciences, conducted a 3-year survey of willow trunk-dwelling insects in 25 parks and greenbelts within the 6^th ring road of Beijing, the urban area of which expanded in a typical concentric pattern. Change pattern of insect diversity along the urbanization gradient was studied. The environmental factors affecting this spatial pattern were also identified. The results showed a significant influence of urban expansion on insect diversity. It was estimated that within a 30-km limit, species richness and abundance might be reduced by one species and 60% of individuals per 5 km toward urban center. The change pattern of diversity was significantly correlated to landscape variables such as isolation degree and proportion of impervious surface.

These results support that urbanization is one of the most important impact factors to the current global biodiversity. To maximize the conservation value of urban forests, efforts should not only be focused on local afforestation, but also be directed to optimize the structure of urban landscape and to increase the connectivity between urban remnants and natural landscape in outskirts. Besides, the proportion of impervious surface in inner urban zones should also be limited.

Two papers relevant to this research have been recently published by Landscape and Urban Planningand Journal of Insect Conservation. This work was supported by grants from the Agricultural Project Office of Chinese Academy of Sciences, the National Natural Science Foundation of China, Ministry of Science and Technology of China, and the Chinese Academy of Sciences for Postgraduate Research, Innovation and Practice.

Huang D, Su Z, Zhang R*, Koh LP (2010) Degree of urbanization influences the persistence of Dorytomus weevils (Coleoptera: Curculionoidae) in Beijing, China. Landscape Urban Plan 96:163–171. (* Corresponding author.)

Su Z, Zhang R*, Qiu J (2010) Decline in the diversity of willow trunk-dwelling weevils (Coleoptera: Curculionoidea) as a result of urban expansion in Beijing, China. J Insect Conserv. doi:10.1007/s10841-010-9310-6 (* Corresponding author.)