Deforestation and land degradation is caused by multiple forces, including extreme weather conditions particularly drought, and human activities that pollute or degrade the quality of soils and land utility negatively affecting food production, livelihoods, and the production and provision of other ecosystem goods and services. About 38% of Sierra Leone’s remaining land covered by forest is decreasing, principally as a result of anthropogenic activities which can all be attributed to poverty as the underlying cause of much of the forest degradation and deforestation. The main drivers of deforestation in Sierra Leone are: urbanisation, mining and quarrying, agriculture slash and burn farming, fire wood and charcoal production and timber production.

Although degradation processes do occur without interference by man, these are broadly at a rate which is in balance with the rate of natural rehabilitation. The most frequently recognised main causes of land degradation include: deforestation, over-cultivation of cropland, overgrazing of rangeland, waterlogging and salinization of irrigated land, and pollution and industrial causes. Within these broad categories a wide variety of individual causes are incorporated. These causes may include the conversion of unsuitable, low potential land to agriculture, the failure to undertake soil conserving measures in areas at risk of degradation and the removal of all crop residues resulting in 'soil mining' (i.e. extraction of nutrients at a rate greater than resupply). They are surrounded by social and economic conditions that encourage land users to overgraze, over-cultivate, deforest or pollute.

Summary of Established Reserves by Ecosystem

Ecosystem Type	Number of Reserves	Total Land Area, ha	Categories Represented
Montane	2	43,720	National Park, Game Reserve
Rainforest	27	124,789	Forest Reserve, National Park, Game Reserve, Game Sanctuary
Savanna	3	113,500	National Park, Game Reserve, Game Sanctuary
Wetland	13	350,677	Strict Nature Reserve, Game Sanctuary, Game reserve, National Park, Important Bird Area
Marine	1	300,000	Inshore Exclusion Zone (IEZ)

 Designated Reserves and Corresponding Areas in Sierra Leone

  Tree cover by percent canopy cover (2000)

Provinces	Area, hectares
	>10%	>15%	>20%	>25%	>30%	>50%	>75%
Eastern province	1,566,122	1,558,959	1,510,658	1,500,753	1,457,222	1,280,872	166,812
Northern province	3,552,151	3,484,591	2,866,737	2,781,735	2,434,927	1,014,674	41,492
Southern province	1,956,457	1,919,306	1,757,924	1,742,137	1,680,631	1,267,176	30,856
Western area	62,996	59,499	49,923	48,877	45,098	26,565	3,421
National	7,137,726	7,022,355	6,185,242	6,073,503	5,617,878	3,589,287	242,582