Carbon storage and tree species diversity of urban parks in Kumasi, Ghana

Abstract

Though essential in combating climate change, conserving biodiversity and providing myriad ecosystem services, urban parks in Africa, are challenged by rezoning, encroachment and other pressures. Furthermore, research on urban park tree diversity, dominant species and carbon stocks of parks in developing countries in Africa are scanty. This study assessed the carbon stocks, tree species diversity and stand structure in public parks within Kumasi metropolis. In each selected park, four 40 × 40 m plots were randomly sampled. The heights, diameters, and crown width of all woody vegetation with a diameter at breast height (DBH) greater than 10 cm, were measured and carbon stocks determined. The stand density (p = 0.0546), DBH (p = 0.004), total tree height (p = 0.01), basal area, and carbon stocks (p = 0.018) differed significantly among parks. The carbon stocks of the parks were 80.73 ± 8.77, 45.10 ± 4.83, 76.26 ± 30.19 and 9.59 ± 2.13 MgCha⁻¹ at Kumasi Zoological Garden, KNUST Botanical Garden, Royal Golf Course, and Rattray Park, respectively. With an average of 53.88 ± 11.70 MgCha⁻¹ and 43 species, the public parks in Kumasi have the potential to alleviate climate challenges and conserve biodiversity. The park species composition slightly deviates from the 10/20/30 benchmark stipulated for urban forests. Increasing park tree cover by restoring degraded sections of parks with tree species with high carbon densities, increasing the area and number of parks per city, adopting integrated park management approaches and plans backed by appropriate legislation and policies in cities in Africa could significantly enhance urban climate resilience, conserve biodiversity, and mediate mitigation and adaptation to warmer cities.