The value of pocket parks in preserving urban butterfly diversity

Abstract

Butterflies, valued for their aesthetic and ecological value, are key subjects in urban biodiversity research. Our study focused on the often-overlooked roles of pocket parks, which are micro-greenspaces and small amusement parks open to the public. Despite their limited size, pocket parks are vital in maintaining the diversity of urban butterflies. We contrasted pocket park diversity with urban parks in Beijing, China. Next, using hierarchical clustering, we classified butterflies into exploiters, adapters, and avoiders based on how well they adapted to urban environments. Finally, we used Logistic regression and Poisson regression to build generalised linear models for all species and each of the three groups separately, allowing us to investigate the differences in the effects of variables from food resources and shelters on various butterfly groups in pocket parks. The results showed that although the primary restrictions differ depending on the group, pocket parks can serve as habitats for most species. Management intensity, pocket park area and nectar plants were significant variables for all species. The tourist intensity and host plants were variables that affected the presence of exploiters. Host plants, nectar plants, and management intensity all affected adapter diversity. Pocket parks’ area was only affected avoiders significantly. These results suggest that pocket parks have roles as source and sink habitats for exploiters and adapters and as stepping stones and corridors for most butterfly species inhabiting cities.