A Study On The Differences And Influencing Factors Of Butterfly Species And Functional Diversity In Urban Green Spaces

As an important component of urban ecosystems,urban green spaces serve as crucial habitats and migration corridors for urban wildlife.In-depth research into urban green spaces can contribute to a better understanding of the biodiversity within these spaces.Existing studies have primarily focused on species diversity,and there is a lack of research combining both species diversity and functional diversity within urban green spaces.Based on this,the present study selected 80 green spaces in Hefei,Anhui Province,China,and butterflies as indicator species,and conducted one-year field surveys on 187 transects once a month.Based on clarifying the differences in butterfly species diversity and functional diversity among different types of urban green spaces,this study used methods such as correlation analysis,generalized linear models,redundancy analysis,and RLQ analysis to quantify the impact of influencing factors on butterfly species diversity,functional diversity,and functional traits.The study aimed to elucidate the relationship between butterfly species diversity and functional diversity and to provide new ideas and methods for urban green space planning,design,quality improvement,and effective enhancement of urban green biodiversity.The main research results are as follows:(1)The one-year survey observed and recorded 4,822 butterflies belonging to 55 species from 40 genera,17 subfamilies,and 5 families.Among them,the most abundant families were Lycaenidae and Pieridae,accounting for 88.43% of the total number.The most common species were Pseudozizeeria maha,Pieris rapae,and Eurema mandarina,which accounted for 52.18% of the total number.(2)Differences exist in the species diversity and functional diversity of urban green space among different types.In terms of species diversity,butterfly abundance,richness,and diversity indices were significantly higher in park green spaces than in residential and street green spaces(P<0.05).Among different urban regions,the mean abundance and richness of butterflies were highest in Baohe district,followed by Yaohai district,Luyang district,and Shushan district.The mean richness of butterflies was highest outside the second ring road among different urban loops,with a value of 9.273.In terms of functional diversity,the mean functional richness(0.252),functional dispersion(0.255),and Rao’s quadratic entropy(0.077)of butterflies in park green spaces were significantly higher than those in residential and street green spaces.Among different urban regions,the mean functional richness of butterflies was highest in Baohe district with a value of 0.171,while the mean Rao’s quadratic entropy of butterflies was highest in Yaohai district with a value of 0.068.Among different urban loops,the mean functional richness of butterflies was highest outside the second ring road,followed by the second ring road and the first ring road.In addition,differences in the functional traits of butterflies were found among different types of green space.The probability of eight functional traits occurring in park green spaces was higher than in residential and street green spaces.(3)The impact factors have different effects on butterfly functional and species diversity.The optimal generalized linear models showed that nine impact factors had a greater explanatory power for butterfly species diversity,while their explanatory power was lower for functional diversity.Butterfly abundance,richness,and functional richness had the highest model explanatory power,accounting for 66.8%,68.8%,and 45.1%,respectively.Correlation and redundancy analyses revealed that nectar plant richness spontaneous nectar plant richness,water area,and area of plot were important impact factors for butterfly species diversity,while the richness of nectar plant richness and distance from city center were important impact factors for butterfly functional diversity.Moreover,there were significant positive correlations between butterfly species diversity and functional diversity indices in urban green spaces.RLQ analysis results showed that the relationship between butterfly functional traits and environmental variables could be summarized by the first two RLQ axes,which accounted for 78.7% and 13.1% of the total covariation,respectively.(4)This study shows that in high-density cities,urban green spaces are important habitats for butterflies.Although they cannot replace natural environments,they can serve as shelters and transit stations for urban wildlife such as butterflies.Urban planners and managers should fully recognize the importance of urban green spaces and actively encourage residents to engage in gardening activities,promote the construction of near-natural plant communities in green spaces,implement eco-friendly management practices,pay attention to the use of local plants and seasonal flowering plants,and make reasonable use of various urban green spaces,to enhance urban biodiversity.