Mugo, Mware J.Mutiso, Festus M.Cheboiwo, JoshuaSang, FrancisTarus, George K.2020-10-132020-10-132015International Journal of Agriculture and Forestry 2015, 5(2): 79-91https://karuspace.karu.ac.ke/handle/20.500.12092/2428DOI: 10.5923/j.ijaf.20150502.02In the past, Mau forest complex has faced a wide range of disturbances majorly anthropogenic in nature. In this paper, the ecosystem floristic composition, richness, diversity and affinities are evaluated. Diameter at breast height (dbh) was measured and types and levels of disturbances recorded in plots, dbh of saplings measured in subplots and seedlings counted in microplots. To obtain the floristic composition and richness, we categorized species based on their families, development stages and life forms. Shannon-Wiener information index (H’) and Jaccard (JIA) and Sorensen(S) similarity indices were used to evaluate the species diversity and similarity respectively Trees, recorded belonged to 52 species, 45 genera and 31 families for seedlings; 43 species, 38 genera and 29 families for saplings and 55 species, 48 genera and 31 families for mature trees. The most species-rich family was rutaceae with six species followed by moraceae and flacourtiaceae with five. Western Kedowa had the highest diversity. Northern and Western Kedowa were the most similar pairs. Past and present disturbances and aggressive proliferation of the invasive; Trichocladus ellipticus (Eckl. and Zeyh) are the main causes of low species diversity and richness. In conclusion, the sites are floristically dissimilar but at varying degrees. The post-disturbance recovery on different sites is following different trajectory successional pathways. We recommend that the on-going disturbances should be curtailed to promote regeneration and successful recruitment of non-pioneer species.enTropical forestsMau ecosystemFloristic compositionSpecies richnessDiversity and similarity indicesArticle