The colonizing flora ofCanarium schweinfurthii in the grassfields of Cameroon

Abstract

Agroforestry affords diversification and intensification of farming systems through the integration of indigenous trees such as canarium (Canarium schweinfurthii [Burseraceae]) which produce marketable products. Although biodiversity in agrosystems is one of the cornerstones of sustainability, little is known about the colonizing organisms of the species introduced. A study was carried out in six Divisions of the grassfields of Cameroon in order to identify the most common epiphytes and parasites of the canarium tree. Sixteen species of vascular epiphytes were recorded, of which 93.75% were holoepiphytes and 6.25% hemiepiphytes. Of the different families encountered. Orchidaceae represented 62.50%, Polypodiaceae 25%, and Davalliaceae and Cactaceae each only 6.25%. In the grassfields of Cameroon, the distribution patterns of vascular epiphytes vary in two ways. Horizontally, there is a significant difference between divisions (P<0.001).Microsorium punctatum andRhipsalis baccifera were specific to Menoua Division andMicrocoelia macrorrhynchia to Mezam Division. Vertically, there is also significant variation from the tree base to the canopy (P<0.001), the lower and middle canopy being the preferred positions. Four species of parasites were recorded:Ficus thonningii, Ficus vallis-choudae (Moraceae),Hymenodyction floribundum (Rubiaceae) andTapinanthus loranthus (Loranthaceae). The Moraceae and Rubiaceae prefer the basal and lower trunk, whereas the Loranthaceae prefer the lower and upper canopy of the tree. The parasites, in contrast to the epiphytes, lead to the death of the canarium tree.