Floristic Inventory of Woody Species in the Manengouba Mountain Forest, Cameroon

Abstract

This study aims to assess the vegetation structure and diversity of woody species in the mountain forest of mount Manengouba, and compare the values obtained with those from other tropical regions of the world.

A quantitative inventory of a 1-ha plot was achieved by plots of rectangles taking into account all trees whose diameter at breast height (DBH) was superior or equal to 10 cm, and the parameters of floristic diversity were calculated using the standard methodology.

A total of 763 trees, belonging to 40 species, were inventoried. The total basal area was 61.6 m²/ha.. Most of trees had between 10 and 15 m height and diameters between 10 and 20 cm, but an important number of individuals attained even higher values, up to 25 m height and 115 cm of diameter. The 4 most important families in terms of density, diversity and dominance were Rubiaceae, Euphorbiaceae, Araliaceae and Myrsinaceae. They represent 70.8% of the Family Importance Value (FIV). The specific composition reveals that a small number of common species dominate the forest, 15% of species represent 54.59% of the Index of Value Importance (IVI). They are Macaranga occidentalis, Rapanea melanophloeos, Maesa lanceolata, Polyscias fulva, Psydrax arnoldianu and Rothmannia urcelliformis. A fraction of species (32.5%) is only represented by 1 individual.

In conclusion, in the Manengouba montane forest the diversity is weak, the density and dominance are in the higher fringes of the values obtained in most forests of tropical regions of the world. The family Rubiaceae displaced the family Leguminosae in the Manengouba forest even though the Leguminosae is the most important family in the lower and sub mountain forests of the tropical regions of the world.