Biodiversity and Carbon Storage in a Tropical Urban Park: Implications for Nature-Based Solutions in Jakarta, Indonesia

Urban green open spaces play a critical role in mitigating greenhouse gas emissions and enhancing biodiversity in rapidly urbanizing tropical megacities. This study aims to characterize vegetation structure and species diversity, as well as quantify above-ground carbon stocks in Taman Bendera Pusaka, South Jakarta, Indonesia. The results are expected to inform evaluations of urban parks’ contribution as nature-based solutions. A complete tree census was conducted between August and September 2025, recording diameter at breast height, height, and species identity for all individuals. Above-ground biomass (AGB) for woody trees was estimated using a widely applied pantropical allometric model developed for humid tropical forests, while separate generalized equations were applied respectively to the palms and bamboos groups to account for their distinct morphological characteristics. The estimated biomass values were subsequently converted into carbon stocks and CO2 equivalents. Biodiversity was evaluated using Margalef richness, Shannon–Wiener diversity, and Pielou’s evenness indices. A total of 2459 individuals were recorded. Langsat Park had the highest species richness (S = 79) with diversity (H′ = 3.38; E = 0.77), and Leuser (S = 78) with highest diversity (H′ = 3.44; E = 0.79), whereas Ayodya Parks showed the lowest structures and diversity values (S = 33; H′ = 2.18; E = 0.68). Total AGB reached 5873.63 Mg, with a mean carbon density of 444.64 Mg C ha−1 or 1631.82 Mg CO2 ha−1. Carbon storage was largely driven by a few dominant ornamental palms, particularly Roystonea regia, although native canopy trees contributed to structural stability. These findings show that even relatively small tropical urban parks can serve as significant localized carbon storage while sustaining urban biodiversity, underscoring the value of structurally diverse, native-enriched planting strategies for resilient urban forest management.