Plant Diversity of Concessions Held by Catholic Religious Groups in Three Cities of the Democratic Republic of the Congo

Urbanization’s environmental challenges have increased interest in urban biodiversity, traditionally focused on public green spaces, which are shrinking as urban growth escapes government control. This study examines the understudied role of private actors—specifically Concessions held by Catholic Religious Groups (CRGs)—in biodiversity conservation across three DRC cities (Bukavu, Kisangani, Lubumbashi). CRGs were selected due to Catholicism’s dominance and socio-economic influence in the DRC. A systematic flora inventory of 70 randomly sampled CRGs identified 220 species from 76 families and 185 genera. Although the CRG area was smaller in Lubumbashi (1.1 ha) than Bukavu (3.7 ha) and Kisangani (5.2 ha), the area did not correlate with species richness. Plant composition varied significantly within and between cities, dominated by phanerophytes and exotic species. These findings underscore the importance of including private stakeholders in urban biodiversity conservation.