Effects Of Urbanization On Bird Diversity And Plant-bird Network In Wuhan City

Rapid urbanization has destroyed the urban forest ecosystems,leading to a reduction in biodiversity and affecting interspecific interactions between plants and animals.Birds are sensitive to changes in habitat structure,anthropogenic disturbance and are one of the animal groups most sensitive to urbanization.Understanding the bird composition,diversity of communities and the interactions between birds and plants,in the context of urbanization,will help to explore the impacts of urbanization on wildlife and the stability and function maintenance of ecosystems.Wuhan city is a typical sample of rapid urbanization in China.Thus,Wuhan city is a good example for studying the effects of urbanization on bird diversity.In this study,I studied bird diversity in urban forests using line-transect and point-count,and monitored plant-bird feeding interactions using infrared cameras along the urban-suburb gradient during July 2020 to December 2022.The results showed that:(1)A total of 144 species of birds,belonging to 16 orders,45 families,were recorded during the experimental years.The common species were Passeriformes,dominated by the Chinese Bulbul(Pycnonotus sinensis),Yellow-bellied tit(Pardaliparus venustulus),and Great Tits(Parus cinereus).The bird fauna is dominated by Oriental species.The residence type was dominated by resident birds.(2)Species and functional diversity of birds were significantly and positively correlated with the urban-suburb gradient.However,there is no significant correlation between bird diversity and patch isolation,area or shape index.This may be due to the larger patch areas we selected,the presence of greenway connections between patches,or the strong dispersal ability of birds.(3)The proportions of large-sized birds,carnivorous birds,fruit-eating birds,dedicated habitat birds,non-companion nesting birds,and ground-nesting and rock-wall nesting birds were significantly positively correlated with the urban-suburb gradient.Besides,the proportion of other birds were significantly negatively correlated or not correlated with the urban-suburb gradient.The results indicate that specialized birds are more sensitive to urbanization than general species.(4)Bird composition was significantly correlated with the urban-suburb gradient and patch area.This may be related to the higher requirements for habitat and large area of some specialized birds and large birds,such as the Reeves’ s Pheasant(Syrmaticus reevesii)and the Blue-throated bee-eater(Merops viridis).There is no significant correlation between bird composition,patch isolation or shape index,which may also be related to the larger patch area or the high dispersal ability of birds.(5)The stability of the bird-patch feeding network increased with the urban-suburb gradient.Species removal results show that birds with high generalization are the key species to maintain connectance and nestedness of the network,such as the Chinese Bulbul.Birds with high specificity and high interaction intensity are the key species to maintain network modularity.These results suggested that urbanization had negative impacts on bird diversity and the interactions between plants and birds,reducing the degree of ecological space use and ecosystem stability of bird communities.Our study explored the impact of urbanization on bird composition and diversity as well as plant-bird interactions in Wuhan city,to help maintain ecosystem functions and services.It also provides references for the protection of biodiversity and the development planning and management of forest ecosystems under rapid unbanization.