Assessment of the Floral Diversity along Disturbance Gradient in Kaya Muhaka Forest, Msambweni District

Abstract

Kaya Muhaka Forest in the Kenyan Coast is one of the remianng lowland forest patches belonging to Zanzibar-Inhambane vegetation mosaic of Eastern Africa, which are rich in \ endemic and threatened flora and fauna. Although gazetted and protected as a national monument, the forest biodiversity is still endangered. This research attempted to establish the flora diversity along disturbance gradient ranging from the forest core to the agro-ecosytems of the forest. The belt transect method was used where quadrants of 20m x 20m placed at intervals of every 250m were systematically selected along two parallel transects of 3km long each and all the plant species recorded. An additional nine plots of similar size and placement were surveyed on three parallel transects of 1km each established from the edge of the forest to the forest core. The flora diversity was calculated by use of the Shannon Wiener Index of diversity. The Importance Value Index, forest strcture, the species area curve and dominance were determined. Other ecological attributes established included species composition, and canopy cover. The distribution and conservation status of endangered species was studied by means of random walks and georeferencing the target species using Global Positioning System Forest disturbance was also recorded by use of indictaors such as presence of paths, tree stamps and evidence of firewood collection. Scorodophloeus fisheri (Taub) J. Lion was the most important species in the forest and Cocos .nucifera L. was the most important in the farmland. A total of 492 species in 92 families were recorded. The forest was found to be heavily disturbed with numerous paths crossing it. The threatened speices are not protected and they risk being logged. There was a high diversity of plant species in the Kaya Muhaka forest and agro-ecosystems. The forest is homogenous with most of the species being indigenous and endemic. The protection of the forest should be improved. Further research should be done on the conservation, presence and mapping of the endangered species in Kaya Muhaka forest.