Gallery forest is found in relic patches in the upper (freshwater) reaches of the bolongs. These relic forest patches are comparable in composition and structure to the Fathala forest within the adjacent Delta du Saloum National Park with the most abundant woody species being Anthostema senegalensis and Dialium guineense (c,f Lykke. 1994). Other notable species include Khaya senegalensis, Detarium guineese, Alchorea cordifolia and Afzelia africana. The forest on the Duniajoe Bolong is quite degraded through a combination of clearance of the understorey for rice cultivation, selective felling and fire damage.
Dry Woodland and Wooded Grassland
36 Woodland is defined as having a canopy cover of more than 40% and reaching a height greater than 8m, while wooded grassland has a canopy of 10-40%. [Within Niumi National Park land elevated above the seasonally flooded areas and valley bottoms falls within one or the other of these categories with the exception of some cleared agriculture land.]
The dominant species found within these vegetation types are Parkia biglobosa, Daniellia oliveri, and Pterocarpus erinaceus. Shrubby species found in association include Combretum nigricans, Dierostachys glomerate, Guiera senegensis and Ziziphus mauritinia.
These species are more dominant in locations where there has been clearance for agriculture in the past or a high incidence of fire damage to the vegetation giving rise to bushland or thicket. Dense regeneration of Daniellia oliveri is often found in fallow agricultural land.
The understorey in both woodland and grassed woodland is dominated by the grass Andropogon gayanus which reaches heights of over 2m. Other grasses which occur include Echinochloa colona and Chloris spp.
On the Island of Jinack and the sandier soils immediately east of the Niji Bolong, the woodland has a higher incidence of Parinari macrophylla, Ficus spp and Tamarindus indica. Maytenus senegalensis is common in this woodland type.