FLORISTIC COMPOSITION AND STAND STRUCTURE OF THE MANGROVE FOREST IN CROSS RIVER STATE, NIGERIA
Egor B. Etigale1, Oluwayinka S. Oke2, Shadrach O. Akindele2, Victor A. J. Adekunle2and Opeyemi Olajide
ABSTRACT
The mangrove forest in Cross River State was assessed for information on its current plant species composition and density as well as trees stem-diameter distribution. Simple random sampling technique was used to select ten sample points on a gridded map of the mangrove forest. The ten selected sample points were located on the ground using their coordinates. At each sample point, one cluster consisting of five 20 m x 20 m nested plots laid alternately at 20 m intervals along a 200 m long transect was established. At the centre of each plot, a 2 m x 2 m quadrat was established as a nest. All living trees, shrubs and palms (with erect stems) ³ 5cm in dbh were identified, counted and measured in the 20 m x 20 m plots, while trees’ and palms’ juveniles (<5cm in dbh), Acrostichum aureum, Nypa fruiticans fronds and their stumps were identified and counted in the 2 m x 2 m quadrats. The data were analysed using Microsoft Excel. A total of 22 plant species, belonging to 20 genera and 15 families were encountered in this study. These consisted of 15 species of trees, 2 species of shrubs, 4 species of palms and 1 species of ferns. Nypa fruticans was the most abundant species in the area. Total number of adult trees recorded was 547. Rhizophora racemosa (156), with a population density of 78 stems per hectare was the most abundant tree species. The stand structure showed an inverse J-shaped diameter distribution pattern.
Keywords: species Composition, Density, Trees Stem-Diameter Distribution, Mangrove Forest, Cross River State.