Distribution Patterns And Mechanisms Of Bird Species Diversity And Community Structure In Chinese Urban Parks

China is one of the countries with richest biodiversity in the world,and it is also one of the countries with the highest ratio of urbanization.In recent years,with the increasing focus on the urbanization problems,urban ecology has gradually become an important research topic in ecology,and the biodiversity pattern and its influencing factors have always been one of the hot topics of urban ecology.So far no one has carried out research on bird species diversity and community structure in urban parks in whole China.Based on the fact that park is an extremely important habitat plaque in the urban ecosystem and birds are an important biological group,this study investigated the present situation of bird diversity in Chinese urban parks,and assessed the correlations between bird species diversity,phylogenetic structure,functional structure and human activities(park area,population density and normalized difference vegetation index),natural factors(mean annual temperature,mean annual precipitation,paleoclimatic change,and altitudinal range).By collecting the published data on urban park bird community,extracting various data on environmental factors and conducting linear regression analyses,the main results of this study are as following:(1)This study collected the bird community data of 140 urban parks in 17 cities.A total of 495 bird species were found,belonging to 19 orders and 75 families,and the Passeriformes accounts for the main part,with 37 families and 287 species.More importantly,the phylogenetic diversity of the 495 bird species accounts for 49% ofthe phylogenetic diversity of all Chinese birds,the functional diversity of 495 bird species accounts for 80% of the functional diversity of 1209 Chinese bird,and the number of omnivorous(40%)and carnivorous(38%)birds was the highest.(2)The 495 species contain one critically endangered species(Aythya baeri),eight endangered species,11 vulnerable species and 53 near threatened species.And three species(Larus relictus,Ciconia nigra,Otis tarda)belonging to the first class of the national key protected wild birds,57 species belonging to the second class of the national key protected wild birds.(3)The general linear regression models and the linear mixed-effects models showed similar results,e.g.,the two factors most associated with park bird species diversity were altitudinal range and park area;the two factors most associated with park bird phylogenetic structure were mean annual precipitation and paleoclimatic change in temperature;the two factors most associated with park bird functional structure were mean annual precipitation and park area.(4)The results of residual analyses showed that when the effects of anthropogenic factors were controlled,park bird diversity was significantly associated with all natural factors(mean annual temperature,mean annual precipitation,paleoclimatic change in temperature,paleoclimatic change in precipitation and altitudinal range);park bird phylogenetic structure was significantly associated with mean annual temperature,mean annual precipitation,paleoclimatic change in temperature and altitudinal range;park bird functional structure was significantly associated with mean annual temperature,mean annual precipitation and altitudinal range.Notably,when controlled the effects of natural factors,there was only one significant relationship between bird species diversity,phylogenetic structure,functional structure and anthropogenic factors,e.g.,species diversity was positively correlated with park area,and population density and normalized difference vegetation index did not show significant relationships with bird diversity and community structure.Our study shows that Chinese urban parks harbor high bird species diversity,phylogenetic diversity and functional diversity,and could play an important role in protecting endangered birds and key protected wild birds.In addition,in the formation of bird diversity and community structure in Chinese parks,natural factors play a greater role than anthropogenic factors,again indicating the critical role of urban parks in the conservation of bird diversity.