Ornamental plant diversity, richness and composition in urban parks: studies in Metro Cebu, Philippines

Abstract

Urban parks are essential for a city’s sustainability. Thus, evaluating and determining the plants propagated in these urban parks is required for better future planning and for development of effective management strategies in urban green spaces in the Philippines. The study was conducted to determine native and exotic ornamental plant composition in the top five most visited urban public parks in Metro Cebu: Plaza Independencia, Senior Citizen Park, Fuente Osmeña Circle, Heritage Park and Plaza Hamabar. A total of 132 quadrats were established using the ground surveying technique to document all ornamental plants present. Diversity indices were also measured, which included abundance, richness, evenness, Shannon diversity and Simpson diversity indices. The chosen sampling sites were also categorized based on functional classification. In total, 28 647 individuals of native and ornamental plants were recorded. In terms of richness, 100 plant species were identified in all parks (85 species in Plaza Independencia; 17 species in Senior Citizen’s Park; 17 species in Fuente Osmeña Circle, 11 species in Heritage Park and 18 species in Plaza Hamabar). About 95% of the species were exotic and only 5% were native. Results on biological indices showed that Plaza Independencia was the most diverse in terms of the Shannon and Simpson diversity indexes, with the respective values of 2.775 and 0.896. In contrast, Senior Citizen Park had the lowest Shannon and Simpson diversity index (0.774 and 0.324, respectively). Plaza Hamabar had the highest evenness (0.743) while Senior Citizen’s Park had the lowest evenness (0.273). Dominance of exotic ornamental plant species over native ones in the top five most visited parks can be explained by various factors such as park category, functional classification and management options.