Natural Regeneration Dynamics of Tree Seedlings on Skid Trails and Tree Gaps Following Selective Logging in a Tropical Moist Semi-Deciduous Forest in Ghana

One of the main threats to the sustainability of timber production in naturally managed forests in Ghana is insufficient regeneration of timber tree species. This study assessed regeneration success of a logged forest by comparing the species composition, diversity, density, recruitment, mortality, and growth of naturally established seedlings in 160 seedling plot samples of 50 m2 located randomly on main skid trails, secondary skid trails, felled tree gaps and unlogged parts of the same forest. The study was done within a 134-ha compartment in a selectively logged moist semi-deciduous forest in Ghana over a period of 33 months involving four enumerations. Seedlings population was initially dominated by pioneers, but after 33 months, population in all sites was dominated by non-pioneers. Seedling densities showed an increase initially in all the sites after logging, but declined after 10 months. The high seedling densities were driven by four (Albizia zygia, Ceiba pentandra, Celtis mildbraedii and Turreanthus africanus) out of the 37 species that regenerated. All four species exhibited a period of exceptionally high new seedling recruitment in the first 10 months. Diversity differed significantly among disturbance types initially, but after 33 months diversity was lower in the unlogged areas though not significant. Seedling mortality was initially greater in unlogged areas of the forest and growth rates higher in the logged areas. These results show that disturbed areas appear to be suitable sites for the regeneration of timber species following logging, although the long-term fate of trees growing on these areas remains uncertain as growth rates declined with time.

Domestication and Sustainable Use of Genetic Resources of a Native Tree with High Economic Potential in Ghana

Allanblackia parviflora A. Chev., an underutilized fruit tree species commonly found in tropical rainforest of West Africa, has potential for integration into agroforestry systems for economic and environmental benefits. The seed oil of A. parviflora is considered economically important but wild fruits collection produces an average of 40 tons of oil annually. However, over 100,000 tons of Allanblackia seed oil is needed annually by food and cosmetics industries. The need to domesticate and conserve A. parviflora to ensure adequate sustainable supply of seed oil and to sustainably manage the genetic resources is therefore critical. This paper reviews the current state-of-the art on domestication and sustainable use efforts of Allanblackia. Propagation methods have been developed to encourage large scale commercial cultivation, include grafting, rooting of stem cuttings and research into improved seed germination. Range-wide germplasm collection has been undertaken leading to establishment of 140 accessions in a gene bank for future source of germplasm. Mother blocks, i.e. established plots consisting of grafts, seedlings and cuttings, have been established at Rural Resource Centres with 58 elite clones, which have been recommended for distribution to farmers. The diversification of cropping systems to include A. parviflora trees is projected to contribute to community livelihoods development and poverty reduction through large-scale production and supply chain development of the species. Furthermore, the integration of A. parviflora into agroforestry systems is important for the conservation of the genetic resources of the species.

Physical and mechanical properties of Klainedoxa gabonensis with engineering potential

Adequate information is sparse for many tropical timbers on their engineering applications, which make their international promotion difficult. The physical and mechanical properties of Klainedoxa gabonensis Pierre ex Engl. （a lesserutilized species） and Entandrophragma cylindricum were compared. K. gabonensis contained more moisture with greater density at 12 % moisture content than E. cylindricum and had a tangential-radial ratio for swelling and shrinkage of 1.31-1.38 and 1.58-1.63, respectively, within acceptable thresholds for engineering/structural timbers. For K. gabonensis, shear parallel to grain was 32.2 ± 0.4-33.5 ±1 N mm^-2; compressive parallel to grain, 80.7 ± 1.4-90.6± 1 N mm^-2; modulus of rupture, 204± 4.0-214 ± 4.0 N mm^-2 and modulus of elasticity, 28,932 ± 664-29,493 ±822 N mm^-2. These properties were superior to those of E. cylindricum [（15.5 ± 0.9）- （15.6 ± 0.6）, （56.4 ± 4.5）-（63.6 ± 1.2）, （99.4 ± 4.7）- （121.3 ± 10.6）, and （9987.4 ± 207）-（10,051 ± 258） N mm^-2, respectively] and compared well with those of several traditional timbers for conslruction and furniture production. Its use would contribute to minimize pressure on the primary timbers in the forests and widen the raw material base for wooden products.

Assessment of Endocrine Disrupting Trace Metals in River Samre at Samreboi in the Wassa Amenfi West District of the Western Region of Ghana

The rational for the study was to assess the levels of endocrine disrupting trace metals in River Samre. The levels of Mercury ranged from 0.01 to 0.02 mg/l (mean of 0.006 mg/l), whiles cadmium levels ranged from 0.002 to 0.011 mg/l (mean of 0.01 mg/l). The high levels of Hg and Cd may have adverse effects on the endocrine system of inhabitants who drink directly from the river without treatment. High levels of mercury and cadmium might be caused by the activities of a Timber and Plywood Company located close to the river and the underlying bedrocks of the area exposed as a result of human activities such as farming. The concentration of lead was below detection limit ( mg/l) but that of Arsenic ranged from 0.001 to 0.007 mg/l (mean of 0.005). Health risk assessment conducted shows that the risk associated with exposure to these metals for now are low. Continuous water quality monitoring is recommended to help protect the resource and also to safeguard human health.

Effect of Storage on the Quality of Sachet-Vended Water in the Tamale Metropolis, Ghana

Sachet water was introduced in Ghana to provide safe, hygienic and affordable instant drinking water to the general public. The aim of the study was to examine the effect of storage on the quality of sachet-vended water produced in the Tamale Metropolis. Two brands of sachet water were sampled freshly after production (Six packs or bags), transported to the laboratory and analysed. Samples of freshly prepared sachet water were then stored at ambient room temperature (at 27°C), in a refrigerator (at 4°C) and in the sun (at 40°C). Samples from these three storage methods were collected and analysed on a weekly and monthly basis for a period of three months. The physico-chemical parameters were within World Health Organization limits regardless of the mode of storage. The pH of sachet water ranged from 6.69 to 7.89 with a mean of 7.38 ± 0.31. There was no significant difference (p > 0.05) in the physico-chemical parameters for the sachet water under the different storage conditions over the period. The concern however was the low concentration of these major ions, sodium, potassium, total hardness, calcium and magnesium which seem to pose direct health concerns. The counts of total heterotrophic bacteria ranged from 0.0 to 73 cfu/1ml with a mean of 19.16 (SD = 21.61) of the sachet water samples. Total heterotrophic bacteria regrowth was observed on the third week in all brands stored and gradually deceased numerically throughout the study period. Total coliform regrowth ranged from 0.0 to 5 cfu/100 ml. There was significant difference (p Based on the findings of this study, it is recommended that Food and Drugs Authority and Ghana standard Board should ensure minerals concentrations of sachet water are improved to meet the general dietary requirement.

Homegardens as a Source of Income for Rural Households A Case Study of Bieha District, Southern Burkina Faso

This exploratory research studied the contribution of homegardens to household income generation. In Burkina Faso, the Bieha department was purposively selected. The initial rapid rural appraisal was complemented by a household survey. Tools of data collection included observation, key informant interview, and focus group discussion. For the survey, eighty households were selected based on systematic sampling. Data was collected by individual interviews at household level, and for statistical calculations, the households were subsequently categorized as small, medium and commercial based on their homegarden size. It was found that all the surveyed households managed homegardens composed of trees, crops and animals. Majority of the farmers （43%） belonged to the small category due to land constraints. Generally, farms contributed more income than the plant component of homegardens. However, when the livestock component of homegardens was added, homegardens became far more important than farms and accounted for over 60% of income generation for all categories. It can be concluded that homegardens are important to rural people for food and cash income.

Evaluation of Breeding Substrates for Cocoa Pollinator, <i>Forcipomyia</i>spp. and Subsequent Implications for Yield in a Tropical Cocoa Production System

A comparative study was carried out to determine the most suitable substrate for breeding of midges (Forcipomyia spp.) and the implications for pollination and yield in a typical cocoa production system in the forest ecological zone of Ghana. For the field experiment, the typically available substrates in cocoa farms which were used as the treatments under cocoa trees were: 1) rotten cocoa leaf litter;2) rotten cocoa pod husks;and 3) rotten banana pseudostem. The untreated cocoa trees served as control. The experiment was set up in a randomized complete block design with three replications. For the laboratory experiment, the design was completely randomized design with four replications. The objective was to determine which substrate best supported breeding of the midges. The rotten banana pseudostem substrate recorded the highest population (7680) of Forcipomyia spp. after 56 days of observation. The cocoa pod husk and cocoa leaf litter recorded populations of 5226 and 1920, respectively. Similar observations were recorded in the level of pollination of the cocoa trees treated with rotten banana pseudostem (95.78%), cocoa pod husks (89.05%) and cocoa leaf litter (68.42%). Application of all substrates to the cocoa tree resulted in a 77% mean reduction in flower abortion as compared to the control. Fruit abortion, on the other hand, was significantly greater in trees treated with rotten banana pseudostem (73.7%) and rotten cocoa pod husks (71.3%) than in trees treated with rotten cocoa leaf litter (54.3%). Application of banana substrate explained 88% of the variation in cherelle production (fruit set) whereas cocoa pod husks and cocoa leaf litter accounted for 71% and 94%, respectively, of the variation in cherelle production. The study concluded that although cocoa leaf litter resulted in average increases in midges population and subsequently not too high levels of pollination, there was a significantly higher number of set fruits retained which implied high cocoa pod yields. Consequently, in accordance with the observed trend cocoa leaf litter should be considered as the most appropriate substrate for midges activity in cocoa for high yields.

Microbial Contamination in Vegetables at the Farm Gate Due to Irrigation with Wastewater in the Tamale Metropolis of Northern Ghana

The rational for this study was to assess the microbial quality of fresh vegetables at the farm gate of the Water Works road vegetable farm at Gumbihini in the Tamale Metropolis. A total of thirty-six (36) vegetables comprising lettuce, amarantus and cabbages and eight (8) wastewater samples were collected at random and analysed for a period of four months, to assess the microbial contamination level. Samples were analysed for total coliforms, faecal coliforms, E. coli and helminthes eggs. All vegetables sampled during the study period recorded high levels of total and faecal coliform bacteria. Mean faecal coliforms for the various vegetables were as follows;lettuce 3.7 ± 0.5 CFU.g-1, amarantus 3.5 ± 0.6 CFU.g-1 and cabbage 3.1 ± 0.6 log CFU.g-1 fresh weight. FC levels were above the International Commission on Microbiological Specifications for Foods (ICMSF) recommended level of 3 log CFU.g-1 fresh weight. E. coli were recorded in lettuce (3.3 ± 0.6 log CFU.g-1 fresh weight) and amarantus (0.6 ± 0.1 log CFU.g-1 fresh weight) but not in cabbages. Lettuce generally recorded high levels of microbial contamination because of the large surface area occupied by its leaves. Two helminth eggs (Strongiloides stercoralis) were identified in lettuce while four (Ascaris lumbricoides) were identified in wastewater. Microbial loads recorded in wastewater were generally higher than that of vegetables. Since most of these vegetables are eaten fresh or slightly cooked, there is course for concern as public health will be adversely affected. Education of farmers and consumers on food safety has to be intensified to avert a possible outbreak.

Empirical Modeling of Annual Fishery Landings

Forecasting plays an essential role in policy formulation and implementation especially in the management of fisheries resources. In this paper, various techniques of forecasting using time series analysis were evaluated on annual fishery production data. In addition to the Box-Jenkins approach, other methods such as the feed forward neural network and exponential smoothing approaches were also examined. A parsimonious model for each forecasting approach was then selected using penalized likelihoods. The chosen models were then evaluated based on their ability to produce accurate forecasts. Implications of the findings as discussed revealed that no particular method was ideal for modeling all landings. Hence when forecasting fishery landings, it is recommended that different structural approaches be compared before selecting an appropriate one for use.

Modelling height-diameter relationships in complex tropical rain forest ecosystems using deep learning algorithm

Modelling tree height-diameter relationships in complex tropical rain forest ecosystems remains a challenge because of characteristics of multi-species, multi-layers, and indeterminate age composition. Effective modelling of such complex systems required innovative techniques to improve prediction of tree heights for use for aboveground biomass estimations. Therefore, in this study, deep learning algorithm (DLA) models based on artificial intelligence were trained for predicting tree heights in a tropical rain forest of Nigeria. The data consisted of 1736 individual trees representing 116 species, and measured from 52 0.25 ha sample plots. A K-means clustering was used to classify the species into three groups based on height-diameter ratios. The DLA models were trained for each species-group in which diameter at beast height, quadratic mean diameter and number of trees per ha were used as input variables. Predictions by the DLA models were compared with those developed by nonlinear least squares (NLS) and nonlinear mixed-effects (NLME) using different evaluation statistics and equivalence test. In addition, the predicted heights by the models were used to estimate aboveground biomass. The results showed that the DLA models with 100 neurons in 6 hidden layers, 100 neurons in 9 hidden layers and 100 neurons in 7 hidden layers for groups 1, 2, and 3, respectively, outperformed the NLS and NLME models. The root mean square error for the DLA models ranged from 1.939 to 3.887 m. The results also showed that using height predicted by the DLA models for aboveground biomass estimation brought about more than 30% reduction in error relative to NLS and NLME. Consequently, minimal errors were created in aboveground biomass estimation compared to those of the classical methods.

Plant Species Selection for Charcoal Production： Dwindling Resource and Further Implications for the Environment

The authors investigated plant species selected for charcoal production. Then, they compared these species with those exploited for charcoal production in Togo, another West African country. The study in Ghana took place in six localities in the Volta Region. Simple ranking was used in the analysis of the species. A total of 35 species belonging to 31 genera were used. Five of these are non-traditional charcoal-making species, implying the increasing diversity of the plants used. Anogeissus leiocarpus ranked first with over 79% of the producers exploiting it and was reported as a preferred or a category 1 species for charcoal production in Togo. Out of the 34 woody species exploited in Togo, 10 are similar to those used in the study area. The ranking used are compared favourably with the categorization used in the Togolese studies.

Charcoal Production in a Cocoa-Farming Area： Plant Species Used and Their Sources

The authors investigated the plant species used for charcoal production and their sources and the willingness of the producers to plant charcoal-making species. Furthermore, the authors indirectly determined the involvement of farmers in charcoal production in Atwima Mponua District of Ghana. A total of 120 producers were interviewed and simple ranking was used for the analysis. Twenty-three plant species were used with the first, second, third and fourth which were Celtis mildbraediL Cylicodiscus gabunensis, Margaritoria discoides and Amphimas pterocarpoides respectively. However, the Amphimas pterocarpoides was not among the traditional charcoal-producing species. The wood used came from seven different sources. None of the charcoal producers had a plantation of charcoal-producing species. Only 13 % of the producers were willing to plant, 87% of them who were not willing to plant indicated that they would leave charcoal production if the resource got finished. The 120 charcoal producers were made up roughly of 56% males, and 44% females and in which 69.2% of them were farmers.

Processing techniques of selected oilseed by-products of potential use in animal feed: Effects on proximate nutrient composition, amino acid profile and antinutrients

The effects of processing by autoclaving(AC), soaking(SK), short-term fermentation(S-TF, 4 d) and longterm fermentation(L-TF, 14 d) on the nutritional composition, amino acid profile and some antinutrients were determined for cottonseed meal(CSM), groundnut meal(GNM) and groundnut husk(GH) in this study. After processing, crude protein content improved by 11% after L-TF, and crude lipid content 25%after SK for CSM; crude protein content improved by 27% after S-TF and L-TF, and crude lipid content 13%after SK for GNM. Soaking and fermentation were shown to significantly increase essential amino acid contents by 44%(SK, methionine) in CSM and 46% in GNM(L-TF, histidine). Phosphorus content was reduced by 59% in CSM and 57% in GNM by L-TF. All processing techniques, with the exception of AC,reduced phytic acid and gossypol contents in CSM and GNM. It was concluded that SK and fermentation were simple, cost-effective, and efficient ways to improve the nutritional value of the selected oilseed byproducts.