Bird Biodiversity Increased with the Area of Urban Green Spaces Expanding after 40 Years of Tree Planting in Beijing

Abstract

Beijing, the capital of China, with a population of more than 21 million, is a mega city that is located on the migration route between East Asia and Australia. Owing to the process of urbanization, more urban spaces have been occupied by artificial buildings and facilities in the past. Since the implementation of the Measures of the National Voluntary Tree Planting Movement by the State Council in Beijing in 1982, urban green spaces (especially urban parks) have been greatly increased, promoting the restoration of ecosystem in Beijing. Interestingly, bird biodiversity greatly increased with the expanding of urban green spaces, and more new records of birds were found by the booming development of bird watching activities in Beijing. A total of 503 bird species have been found in Beijing to date, including 27 Class I species (Aythya baeri, Grus japonensis, Emberiza jankowskii, etc.) and 89 Class II species (Grus grus, Paradoxornis heudei, etc.) in the List of Key Protected Wildlife in China, most of which are the flagship species of the wetland ecosystem and forest ecosystem. This suggests that Beijing has become one of the richest mega cities in the world in terms of bird biodiversity. Therefore, the long-term conservation of urban biodiversity should be considered during the process of urbanization construction.