Browsing by Author "Adomako, J.K."
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Item Comparative Study of the Mangrove Ecosystems of Douala-Edea Reserve (Cameroon) and Songor Ramsar Site (Ghana) Using Parameters of Ecological Value(University of Ghana, 2014-06) Ntyam, S.C.O.; Wiafe, G.; Armah, A.K.; Adomako, J.K.In most tropical countries including Ghana and Cameroon, knowledge of ecological importance of mangrove ecosystem in terms of litter production, structural characteristics, water and soil properties, has been qualitatively well documented and recognised. However, there is scanty quantitative scientific data to back this up. The purpose of this research dissertation was to study and compare the mangrove ecosystems of Cameroon and Ghana two contrasting coastal zones, using parameters of ecological value and to have a better understanding of their interrelationships within mangrove ecosystem as well as the impact of their values or roles to the global ecosystem (marine and coastal) within the West and Central African ecoregion. The study was conducted within the period of two years for both countries (One year in each country), Two major sites were chosen in Ghana (Songor Ramsar site) and Cameroon (Douala Edea Reserve). In each site, three mangrove stands: 1) Avicennia, 2) Rhizophora and mixed (Rhizophora and Avicennia) were selected and marked out, and parameters like litterfall, structural characteristics, water and soil properties were assessed. This research on mangrove ecosystem addressed four objectives: (1) assessment of the structural parameters; (2) assessmentof litter production; (3) determination of physicochemical and climatic factors affecting mangrove structure and productivity; (4) Show the interrelationships between mangrove resources in both countries. The results in both countries showed that, (1) Leaves, twigs, flowers and fruits were present in litter samples all over the study period with highest peak mainly in the dry season, and leaf production accounted for more than 80% in each country; (2) High values of most of the major nutrients (N, P, K, Mg, Ca) investigated and used in evaluation of mangrove ecosystem importance were recorded between March and October for Cameroon mangroves and in December for Ghana mangroves. (3) The mean highest species density was observed in Rhizophora for Cameroon and Avicennia and mixed in Ghana. The mangrove of Cameroon showed greater heights than their Ghanaian counterparts. (4) The values of Physical parameters (DO, BOD, EC, TDS, TSS), and nutrients were most often high in Cameroon, compared to Ghana. Mangrove waters were also found more alkaline in Cameroon than in Ghana. (5) It was observed that in both countries, Avicennia had the highest percentage of silt. In addition to that nitrogen ,phosphorus, leaves (Litterfall), nitrate, Biochemical Oxygen Demand, pH, Phosphate, salinity, Conductivity (Mangrove Water ), percentage organic nitrogen, electrical conductivity, acidity, Exchangeable magnesium, ECEC Effective Cation Exchange Capacity, and available phosphorus Av P (Mangrove Soil), height, basal area and density (Structural characteristics) were the major discriminatory ecological features of the mangroves of Ghana and Cameroon. Correlations with litterfall, structural, water and soil variables indicated that mangrove ecosystem within and across the countries respond differently to environmental conditions. The combination of rainfall, temperature and salinity was a good predictor of variability in the production of litterfall in both countries. This study contributes to a better understanding of how mangrove ecosystems function. Additional work in other geographic areas within the West and Central African ecoregion is needed to provide a broader perspective on the ecological importance of mangrove ecosystem and their impact on the nearby marine and coastal areas.Item Distribution and abundance of small mammals in different habitat types in the Owabi Wildlife Sanctuary, Ghana.(Journal of Ecology and the Natural Environment, 5 (5): 83-87, 2013) Garshong, R.A.; Attuquayefio, D.K.; Holbech, L.H.; Adomako, J.K.Information on the small mammal communities of the Owabi Wildlife Sanctuary is virtually non-existent despite their role in forest ecosystems. A total of 1,500 trap-nights yielded 121 individuals of rodents and shrews, comprising five species: Praomys tullbergi, Lophuromys sikapusi, Hybomys trivirgatus, Malacomys edwardsi and Crocidura buettikoferi, captured in Sherman traps using 20 × 20 m grids. P. tullbergi was the most common small mammal species in all the four habitat types surveyed, comprising 63.6% of the total number of individual small mammals captured. The Cassia-Triplochiton forest had 61.2% of the entire small mammal individuals captured, and was the only habitat type that harboured higher abundances of the rare small mammal species in the sanctuary (H. trivirgatus and M. edwardsi). It also showed dissimilarity in small mammal species richness and abundance by recording a Sǿrenson’s similarity index of less than half in comparison with the other three habitat types. Management strategies for the sanctuary should therefore be structured to have minimal impact in terms of development and encroachment on the Cassia-Triplochiton forest area in order to conserve the rare species and biodiversity of the Owabi Wildlife Sanctuary.Item Effects of Broussonetia papyrifera invasion and land use on vegetation characteristics in a tropical forest of Ghana(Northeast Forestry University, 2018) Adigbli, D.M.; Anning, A.K.; Adomako, J.K.; Fosu-Mensah, B.Y.The purpose of this study was to evaluate the effects of Broussonetia papyrifera (paper mulberry) invasion and land use on the floristic composition of a dry semi-deciduous forest in Ghana. Forty-five plots (25 m × 25 m each), distributed among three land uses—selectively logged (SL); abandoned farmlands (AF); and an undisturbed reference (RF)—were surveyed. Results showed lower tree species richness (S), diversity (H′), evenness (S) and basal area (BA) in the SL (46, 0.78, 0.32 and 269.12 m2 ha−1, respectively) and AF (40, 0.53, 0.45, and 131.16 m2 ha−1) sites compared to the RF site (79, 2.66, 0.87, 963.72 m2 ha−1). Similar patterns were found at the shrub layer, but no differences were observed at the herb layer. Non-metric multidimensional scaling ordination revealed distinct species composition among the land uses. The two disturbed habitats, SL and AF, were associated with increased B. papyrifera invasion particularly in the overstory, with importance value index and mean relative density of 45 and 65.03%, and 42 and 53.29%, correspondingly. However, the species was only sparsely represented in the RF site. Tree density of B. papyrifera correlated negatively with H′, S, E, BA, and native tree density and richness. These findings highlight the strong link between human land use (i.e., logging and slash-and-burn farming), invasion, and vegetation characteristics, and suggest the need to limit these disturbances to conserve biodiversity within tropical forest ecosystems. © 2018 Northeast Forestry University and Springer-Verlag GmbH Germany, part of Springer Nature