Characteristics and influencing factors of taxonomic and functional diversity of butterflies in urban green spaces

Abstract

Against the backdrop of urbanization posing a significant threat to global biodiversity, the biodiversity of urban green spaces and its influencing factors have become a hot topic in biodiversity conservation. However, most studies have focused on taxonomic diversity, neglecting functional and trait diversity. This study investigated the relationship between butterfly communities and urban green space environmental characteristics by analyzing changes in butterfly taxonomic diversity, functional diversity, and traits. We selected 80 urban green spaces in Hefei, Anhui Province, China, and conducted sampling and recording of butterfly traits for one year. Based on the understanding of butterfly taxonomic diversity and trait differences, we explored the effects of environmental characteristics on butterfly taxonomic diversity, functional diversity, and functional traits using methods such as generalized linear regression models, redundancy discriminant analysis, and environment matrix-trait matrix linkage analysis. During the one-year survey, we recorded 4822 butterflies of 55 species. These butterflies were mostly small to medium in size, with a long flying duration, multivoltine, polyphagous, and overwintered as pupae. The diversity and traits of butterflies in park green spaces were significantly higher than those in residential and street green spaces, with little difference across different urban rings and regions. Nectar plant abundance and distance from the city center, and area of plot were important factors influencing butterfly taxonomic and functional diversities. Butterfly communities were positively affected by spontaneous nectar plants and low-intensity management. Finally, we recommend that to create favorable butterfly habitats in urban areas, considering relevant traits such as life history, behavior, and ecological characteristics of butterflies, and providing diverse habitats to maintain population dynamics are necessary. Additionally, strategies should include increasing the diversity of food sources in urban green spaces, increasing the proportion of larval host plants, promoting low-intensity green space management, and using natural meadow greening forms.