Assessing landscape fragmentation and its implications for biodiversity conservation in the Greater Accra Metropolitan Area (GAMA) of Ghana

Abstract

ContextThis paper discusses the impact of urban expansion on the environment, including its effects on biodiversity conservation. As urban areas develop, natural habitats such as forests and agricultural lands are transformed into industrial, commercial, and residential uses, which alters landscape patterns and can lead to fragmentation. Fragmentation can have negative impacts on biodiversity, such as deforestation, alteration of watercourses leading to flooding, reduced availability of food, and increased pollution. The objective of this paper is to provide a comprehensive and data-driven analysis of the urban expansion of Greater Accra Metropolitan Area (GAMA) over time, and its effects on biodiversity. The idea is to capture the changes in land cover and landscape patterns in GAMA from 1991 to 2022 and predict the region’s landscape patterns for 2030. This was achieved by performing a land cover change analysis of GAMA from 1991 to 2022; capturing the evolution of landscape patterns by calculating landscape metrics; and using multiradial fractal dimension as a transition variable to model and predict the land cover and landscape pattern of GAMA for 2030. The landscape metrics revealed extensive fragmentation of the Vegetation land cover type of GAMA, indicating a negative impact on biodiversity conservation, species movements, ecosystem functioning, and long-term ecological resilience. The trends highlight the importance of considering landscape connectivity, habitat fragmentation and spatial arrangement of land cover types for assessing ecological processes and urban development impacts on the environment. Additionally, multiradial fractal dimension of built-up areas is recommended as an explanatory variable for urban growth modelling.