Studies On Avian Community Structures And Affecting Factors In The Greenbelts Of Beijing Urban Area

Urban wildlife is an important component of the urban ecological system. With expansion of urbanization in the world, studies on urban wildlife that is closely related to the survival of human beings, especially those on urban birds, have become a new highlight of urban ecological researches. Avian communities in greenbelts of the Beijing urban area were main investigating target of the present study. Species, quantities and distributions of birds and invertebrates like insects as food of the birds, and species, quantities and structures of plants were totally investigated. Avian communities in greenbelts of urban areas and the relations between the avian communities and their habitat environments were systematically analyzed. Qualities of environmental situation of Beijing urban greenbelts were comprehensively evaluated by taking characteristics of the avian communities as the main indexes.A distinctive feature of the present study is that by taking artificial afforested lands of different functions and at different districts, comparative studies were thoroughly made on quantitative characteristics of avian communities and their relations to habitat environments in the greenbelts of three different ecological functions (namely, the afforested lands in parks, the shelter-afforested lands and the industrial parks) from an view of resource utilizations. Results of the study might provide basic theoretical data for monitoring and evaluating ecological effects of the afforested lands in urban areas.Major achievements of the study as follows:1. Composition analysis of avian communities in greenbelts of Beijing urban area:Within the 131 species recorded during investigations, summer migrants had the most and they accounted for 40% of the total. Birds of Palaearctic species, birds taking animals as main food, birds taking foods on trees and birds nesting in cavities had the most from respects of natural distribution regions, feeding habits, feeding niches and nesting tipes, and they accounted for 47.33%, 61.83%, 30.53% and 30% of the total, respectively. An average density of birds was 9.7824 individual per hm , an average biomass was 2817.5737 g/hm2, and there were 11 dominance species. Indexes of species diversity, uniformity and dominance were 3.2387, 0.4605 and 0.2137, respectively.2. Characteristic comparisons of the summer avian communities in three kinds of functional afforested lands: Number of bird species and density, dominance and biomass of birds of the afforested land in parks was the biggest, uniformity of the avian community of the industrial park was the highest, and differences of the speciesdiversities were similar within the three kinds of functional afforested lands. Similarity of the avian communities between afforested lands of parks and shelter-afforested lands was the highest, and that between afforested lands of parks and industrial parks was the lowest.3. Analyses of the bird-feeding trees in greenbelts: Totally 48 bird-feeding trees were recorded and investigated. Species number of the Chaolai Agro-horticulture Garden was the maximum (21 species), and those of the Tonghui River and banks of the Dongba River were the minimum (each 3 species). Characteristics of the bird-feeding trees in the greenbelts are that both number of species and quantity of the trees were relatively small and distribution of species and quantities were not uniform. Differences between greenbelts were relatively big, arrangements of bird-feeding trees were not reasonal, and seasonal distributions of the bird-foods were not balanced.4. Analyses and evaluations of the bird habitats: Environmental quality of the investigating sampling areas were evaluated by referring evaluation methods of developed countries. The results show that quality of the afforested lands in multipurpose parks of relatively large area was the best and those of the roadside trees and the economic forests were the worst.5. Studies on relations between birds and habitats: In all the habitats investigated, there were notable positive correlat...