Articles

The Douala-Edea National Park is a coastal protected area that opens to the Atlantic Ocean, and contains an abundant wildlife which finds a privilege habitat there, and certain taxa such as epiphytes, which are of particular interest for conservation. In many tropical forests, vascular epiphytes are one of the richest taxa, with major impacts on the nutrient and hydrological cycles. The aim of this research was to study the effect of the disturbance of habitat on the floristic composition of vascular epiphytes in the Douala-Edea National Park. This study was carried out between January - April 2021 in three types of disturbed habitats at the northern part of the park. Three plots of 100 m × 100 m dimensions were laid out across three ecosystems along the Sanaga river. The sampling method consisted in the direct observation of five adjacent transects of 100 m x 20 m dimensions inside each plot. Epiphytes species were evaluated on all trees of DBH ≥10 cm. Epiphytes' life-forms and the position on the host trees occupied by the epiphytes were also recorded. A total of 18 species belonging to 16 genera and 13 families were identified. <i>Culcasia</i><i> sp.</i> was the most common species with a relative frequency of 30.27%. Biological indicators were represented by Ferns, with four species, and Orchidaceae, with one species<i>.</i><i> </i>The epiphytes species richness was highest in the low disturbed habitat (13 species), and lowest in the highly disturbed habitat (8 species). Strict epiphytes were highly recorded in the low disturbed habitat (6 species), and were absent in the highly disturbed habitat. Hemi-epiphytes were the commonest life-form (12 species) in the highly disturbed habitat, and have been defined as indicators of the perturbation of the habitat. Canopy was mostly sollicitated by epiphytes in the low disturbed habitat (66.25%) than the moderate disturbed habitat (49.85%), and highly disturbed habitat (30.66%). It has been found that the different forest sites have an influence on the typology of epiphytic species, and therefore, epiphytic flora should be managed for the conservation of the biodiversity in tropical forests.

This study took place in the Far North region of Cameroon. The general objective was to assess the floristic diversity of the undergrowth of Agrosystems in <i>Azadirachta</i><i> </i><i>indica</i>. The data were collected in 100 m long by 20 m wide transects surveyed in plantations of different ages. In total, 5 transects were carried out, ie a total area of 1 ha per site. The sampling bands were established using the compass, decameter, GPS and wires. The experimental set-up used was a 5-repetition split plot. A total of 7689 individuals divided into 9 families, 13 genera and 16 species have been identified. <i>Guiera</i><i> </i><i>senegalensis</i> and <i>Piliostigma</i><i> </i><i>thonningii</i> are the most common in terms of relative abundance. The analysis of the Family Importance Index (VIF) shows overall that the Combretaceae, and Mimosaceae are the most important in ecological terms. While those of the species show that <i>Guiera</i><i> </i><i>senegalensis</i>, <i>Combretum</i><i> </i><i>micranthum</i> and <i>Acacia</i><i> </i><i>nilotica</i> finally for the genera, it is Acacia, Guiera and Combretum which contains the most important ecological indices. The overall density of species within the plots varies between 129 and 105 ind / ha. The basal area varies from 2.02 to 3.88 m² / ha. The Importance Value Index (IVI) is of the order of 300 in the different plots. The floristic diversity of the undergrowth of Agrosystems (average ISH> 2) shows homogeneity and an even distribution between the different plots. Plots with similarity indices of less than 50% do not meet floristic affinity while similarity indices are high in plots with floristic affinities greater than or equal to 50%. The diameter structure showed a predominance of young individuals. This information drawn from the conclusion of the present study shows that they constitute an important argumentation of the advantages so that the services of agricultural development should be interested in the conservation and valuation of such an agroforestry system for the protection of the environment against the climate change mitigation and sustainable development of local communities.