Citizen science reveals socio-economic influences on solitary bee abundance across multiple scales in a Global South city

Abstract Context Urban ecosystems exhibit complex biodiversity patterns influenced by both socio-economic and ecological factors. While the role of ecological factors is widely recognised, the relationships between socio-economic and ecological factors, particularly across various spatial scales and considering both landscape composition and configuration, remains underexplored. This limits our understanding of urban environments as interconnected socio-ecological systems. Objectives We examine the influence of socio-economic and ecological landscape factors on solitary bee abundance, aiming to elucidate the complex socio-ecological dynamics shaping urban biodiversity across multiple scales. Methods Data on solitary bee abundance were gathered through a citizen science campaign, supported by 347 participants from Johannesburg, South Africa. We explored the correlations and interactions between solitary bee abundance, socio-economic status (i.e. annual household income) and landscape composition and configuration (i.e. urban green cover and NDVI, and urban vegetation patch density and cohesion), assessing these relationships at 300 m, 2000 m, and 5000 m scales. Results Annual household income was significantly positively correlated with solitary bee abundance across all spatial scales examined, likely due to increased investment in gardens with diverse floral resources in affluent areas. In contrast, our ecological factors, including both landscape composition and configuration metrics, exhibited negligible effects on solitary bee abundance across all spatial scales. Conclusions The strong positive relationship between annual household income and bee abundance across scales highlights potential disparities in access to biodiversity and ecosystem services within Johannesburg. Our results indicate the presence of environmental injustice in this African city and reflect the need for integrating socio-economic factors into landscape ecology. Policies on urban greening that consider both socio-economic and ecological factors are essential for equitable, sustainable urban ecosystems.