Covering an area of 71,070 ha, GRNP is characterized by extensive rolling hills cloaked in evergreen and semi-deciduous forest divided into three blocks – Gola North, Central and South. The park comprises the largest remaining area of intact, lowland rainforest in Sierra Leone and is a significant remnant of the once vast Upper Guinea Forest belt of West Africa, a global biodiversity ‘hotspot’ and a priority for international conservation efforts. Botanical assessments have identified close to 1,000 plant species, half of which are endemic to the Upper Guinea Forest ecosystem. The forests of the GRNP have largely remained intact in spite of sporadic logging and a decade of civil war during the 1990s. Regenerating secondary forest (in old logging areas) is largely confined to the edges of the park with the core interior zone supporting high, primary forest and abundant wildlife. Current satellite imagery shows the park as an ‘island of green’ in a largely agricultural landscape, confirming that the park’s forests are continuing to be effectively protected.
Of the 899 species of plant that are known to occur in the park, 232 are tree species. The most common family is identified as Leguminosae, with common species such as Cynometra leonensis and Brachystegia leonensis. However, the most dominant tree species is Heritiera utilis (Sterculiaceae) (Klop et al 2008).
IUCN classification for plants is incomplete. Nonetheless, at least 21 threatened species listed by IUCN have been recorded recently including one, Tieghemella heckelii, that is classified as Endangered and 20 classified as Vulnerable (IUCN 2012). Poorter et al. (2004) classified 278 woody plants in the Upper Guinea forests as rare or threatened based on extent of distribution and threats from human exploitation. Of these, 67 have been recorded in the park.