Comparison of plant communities between primary and secondary tropical forests of Mount Oku, Cameroon

Globally, human populations are rapidly converting large blocks of tropical old-growth forests into small forest patches, embedded within human-modified landscapes, consisting mostly of agricultural fields and pasture lands. Mount Oku commonly known as Kilum-Ijim, situated at the North-western Cameroon is recognized as a globally important center of endemism and a hotspot for biodiversity conservation but now undergoes unprecedented degradation. The aim of this study was to compare the diversity between primary and secondary forests in mount Oku (Cameroon) and determine whether species richness and composition are distinguishable in the two forest types. The vegetation was sampled in 102 plots according to a stratified sampling design so as to cover the altitudinal gradient from 1833 to 2772 m. Forty plots were located in primary forest and 62 in secondary forest. A set of 6 plant traits/characteristics associated with dispersal, establishment, and persistence functions were gathered. A total of 385 vascular plant species were present in the 102 plots. 243 species were common to primary and secondary forest plots, 69 were present exclusively in primary forest plots and 73 in secondary forest plots. The Indicator Species Analysis showed that 38 and 28 species were indicator of primary and secondary forests, respectively. The mean species richness per plot was 45.5 and 44.1 in primary and secondary forests, respectively. Only tree species richness was significantly higher (p < 0.001) in the primary forest. The maximum height of vegetation and density of trees were respectively 19.42 m, 101 stems/ha in primary forest and 11.93 m, 36 stems/ha in secondary forest and show significant difference (p<0.001). Primary forest plots were characterized by phanerophytes, while secondary forest plots were characterized by geophytes and chamaephytes, able to propagate vegetatively and resist disturbances. Finally, there is need to urgently protect the last remnants of ancient forest for their biological value. Key words: Afromontane forest, biodiversity, endemism, human activities, mount Oku, species composition, species richness.