Analysis of Plant Species as Noise Barriers in Air Transportation Activities at Sam Ratulangi Airport, Manado, North Sulawesi, Indonesia

Plants serve as natural noise barriers at airports, particularly in areas surrounding runways and airport terminals. This research aims to analyse plant species that function as noise barriers in response to air transportation activities at Sam Ratulangi Airport, Manado, North Sulawesi, Indonesia. The research was conducted within and around the vicinity of Sam Ratulangi International Airport and its surrounding areas. The research methodology utilised both primary and secondary data. Plant inventories were carried out using purposive sampling. All plant species relevant to the research were recorded and documented, including the species identity and the number of individual specimens. The collected data were analysed using qualitative descriptive methods. The research findings indicate that in the airside area, there are 27 species of understory plants (including grasses, sedges, and broad-leaved species) within the plots, and 12 species found outside the plots. Outside the airside area, 26 species of tree-form plants and one epiphytic species were recorded. Ficus rumphii exhibited the highest relative density among the plant species outside the airside area, with 88 individuals (21.89%), followed by Polyalthia longifolia with 86 individuals (21.39%), and Mimusops elengi with 64 individuals (15.92%). These three species, which function as noise barrier plants, were found outside the airside area and demonstrated higher relative densities compared to other plant species. The noise barrier understory plant species identified in the airport’s airside area with the highest relative density were Poaceae 1 (8.76%), followed by Paspalum sp. (2.78%) and Carex sp. (0.09%). Keywords: Plants, Noise barriers, Sam Ratulangi Airport, North Sulawesi, Indonesia.