ASSESSMENT OF ECOSYSTEM SERVICES IN REHABILITATED LIMESTONE QUARRIES OF BAMBURI, MOMBASA COUNTY - KENYA

Abstract

Bamburi quarries are expansive areas exploited by the Bamburi Cement Company, the largest cement producer in Kenya. These areas undergo ecological restoration, a process that began in 1971 to mitigate the degradation caused through mining. This study sought to elucidate ecosystem services in the rehabilitated site and to demonstrate how restored quarries can provide sustainable services. Random walks were conducted during this study to establish quarry status before and after rehabilitation. Habitats were mapped, biodiversity surveys conducted, and Simpson Diversity Index (D) calculated to provide a measure of community structure for describing the ecosystems. Additionally, land use activities were identified to determine sustainability of the ecosystems services. Results show that over 566.2 hectares are under various land use activities in Bamburi with over 320 hectares (56.51%) of quarry having been ecologically rehabilitated to achieve a soil pH of 7.2 to 7.53 useful for supporting plant growth. About 7.8% of the study site comprised of grasslands and over 2.8% aquatic habitats. Fourteen (14) species of aquatic plants used in water purification were identified. Four hundred and thirty (430) vegetation species support the ecosystem of which 84 species are listed in IUCN data list as endangered, near threatened and critically endangered. Results from Simpson Diversity Index shows diversity of animals (D) = 0.818. The emergent ecosystem delivers provisioning, supporting, regulating and cultural ecosystem services which include fuelwood, herbal medicine, nutrient cycling, soil formation, erosion control, air and water purification, ecotourism, recreation, as well as education. The site attracts over 181,000 visitors annually. Findings from this study can be applied in policy development to promote restoration of quarries for sustainable ecosystem services.