Deforestation is driven by agricultural expansion in Ghana's forest reserves

Emmanuel Opoku Acheampong,Colin J Macgregor,Sean Sloan,Jeffrey Sayer

doi:10.1016/j.sciaf.2019.e00146

Emmanuel Opoku Acheampong, Colin J Macgregor + Show 2 more

Open Access

https://doi.org/10.1016/j.sciaf.2019.e00146

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Abstract

Ghana's protected forest reserves have suffered average annual deforestation rates of 0.7%, 0.5%, 0.4%, and 0.6% for the periods 1990–2000, 2000–2005, 2005–2010 and 2010–2015, respectively. The Ashanti region has recorded the second highest deforestation rates. Despite the government's efforts to maintain and protect Ghana's forest reserves, deforestation continues. We observed deforestation patterns in the Ashanti region of Ghana from 1986 to 2015 using Landsat imagery to identify the main causes of deforestation. We obtained and processed two adjacent Landsat images from the United States Geological Survey's (USGS) National Centre for Earth Resources Observation and Science at 30 m spatial resolution for 1986, 2002, and 2015. We then supported the results with findings from 291 farm household surveys in communities fringing the forest reserves. By 2015, dense forest covered 53.3% of the land area of the forest reserves, and the remaining area had been disturbed. Expansion of annual crop farms and tree crops caused 78% of the forest loss within the 29-year period. Afforestation projects are ongoing some of which employ the participation of farmers, yet agricultural expansion exerts more pressure on the remaining dense forest. Agricultural intensification on existing farmlands may reduce farm expansion into the remaining forest areas. Strengthening and enforcing forest protection laws could minimise the extent of agricultural encroachment into forests. Mixed tree-crop systems could reduce the effects of arable farming on deforestation, limit the clearance of trees from farmlands, enhance the provision of ecosystem services, and improve the soil's fertility and moisture content. A forest transition may be underway leading to more trees in agricultural systems and better protection of residual natural forests.

Highlights

The tropical forest areas of Ghana form part of the Guinea Forest Region of West Africa, one of 34 severely threatened World Biodiversity Hotspots [9]
The net gain of dense forest over the 29-year period was lower than the net loss and this resulted in net deforestation
Settlements/ bare soil/ dry grass that occupied only 0.5% of the land area of the forest reserves increased by 60% annually from 1986 to 2015 (Table 2)

Summary

Introduction

The tropical forest areas of Ghana form part of the Guinea Forest Region of West Africa, one of 34 severely threatened World Biodiversity Hotspots [9]. Human activities have degraded about 85% of Ghana’s Guinea Forest Region. Forest resources contribute up to 38% to the income of Ghana’s forest dwellers and about 6% annually to the Gross Domestic Product of the country [4,8]. The decline of the resource will impact on the livelihoods of those who depend directly on the forest and the economy of the country as a whole. One means to curb deforestation in Ghana is to identify and tackle the drivers of forest loss – the physical human-induced and location-specific drivers of deforestation such as agriculture

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