Journal of Research in Forestry, Wildlife and Environment, 2018
Distribution of tree diameter in a specific stand provides basic information for forest managemen... more Distribution of tree diameter in a specific stand provides basic information for forest management. Little attention is given to the use of probability distribution functions in characterising the stem diameters of most Nigeria indigenous species. This study used Three-parameters lognormal and Weibull probability distribution functions in characterising the diameter of Nauclea diderrichii plantations within a restricted tropical rainforest of Nigeria for sustainable management. Thirty temporary sample plots of dimensions 20 m × 20 m were randomly laid in three age strata (42, 43 and 46 years). Stem diameters of all living Nauclea diderrichii trees with diameter at breast height ≥10.0 cm in all the sampled plots were enumerated. The performance and suitability result revealed that lognormal distribution gave superior description of the stem diameter for the Nauclea diderrichii species in the study area, with least values of Bias (0.00001), Mean absolute error (0.1214), Mean square er...
Journal of Research in Forestry, Wildlife and Environment, 2020
Potting media are important factors to the growth and development of plants. Some plants due to s... more Potting media are important factors to the growth and development of plants. Some plants due to some morphological or physiological adjustments do not attain the necessary seedling growth level expected. This study examined the influence of potting media on the early growth of Treculia africana seedlings. The seedlings were subjected to three different treatments/potting mixtures namely: mycorrhizal soil, top soil and mycorrhizal soil mixed. Each treatment was replicated five times and laid in a Completely Randomized Design. The growth variables measured weekly include; plant height (cm), collar diameter (cm), leaf production and leaf surface area (cm2). The data collected were subjected to analysis of variance and significant means were separated using Duncan multiple range test at 5% probability level. Results revealed that there were significance differences in the growth performance of Treculia africana in all the variables assessed. Seedlings grown in mycorrhizal mixed with top...
Asian Journal of Research in Agriculture and Forestry, 2020
Non-Timber Forest Products are important sources of income that can supplement farming and/or oth... more Non-Timber Forest Products are important sources of income that can supplement farming and/or other activities to the rural dwellers. In spite of this, its potential to improve the standard of living and generate income to rural dwellers has not been known in Awka-North Local Government Area. The study was carried out from January to August, 2017. The study identified the variety of non-timber forest products (NTFPs) available to rural households, the level of income generated by households from these available Non-timber forest products and constraints to Non-timber forest products collection in the study area. Three towns; Achalla, Amansea and Mgbakwu were selected using multi-stage random sampling technique. A total of 100 copies of structured questionnaires were administered to obtain information from respondents who engaged in NTFPs based activities in the selected towns. Data collected were analyzed using descriptive statistics and 5-point Likert Type Scale. The study revealed...
Institute of Forest Science, Kangwon National University, 2018
The tropical forests in developing countries are faced with the problem of illegal exploitation o... more The tropical forests in developing countries are faced with the problem of illegal exploitation of trees. However, dearth of empirical means of expressing the dimensions, structure, quality and quantity of a removed tree has imped conviction of offenders. This study aimed at developing a model that can effectively estimate individual tree basal area (BA) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six 25 m×25 m temporary sample plots (TSPs) were laid randomly in six age strata; 26, 23, 22, 16, 14, and 12 years specifically. BA, Ds and diameter at breast height were measured in all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem cross-sectional areas. Six basal area models were fitted and evaluated. The BA-Ds relationship was best described by power model which gave least values of Root mean square error (0.0048), prediction error sum of squares (0.0325) and Akaike information criterion (-15391) with a high adjusted coefficient of determination (0.921). This study revealed that basal area estimation was realistic even when the only information available was stump diameter. The power model was validated using independent data obtained from additional plots and was found to be appropriate for estimating the basal area of Tectona grandis stands in Omo Forest Reserve, Nigeria.
The type of soil, fauna and flora species that are found in an environment is affected by the ele... more The type of soil, fauna and flora species that are found in an environment is affected by the elevation characteristics of the land. However, the ability to provide techniques and model that will effectively explain the elevation patterns of protected areas will aid sustainable management of the forest and its resources. This study developed Digital Elevation Model (DEM) for Okomu National Park, Nigeria. Point coordinates (2,272) with their respective elevations were randomly obtained covering the entire study area. Interpolated natural neighbour algorithm of the Quantum Geographic Information System was used to generate Digital Elevation Model for the National Park from the elevation data. Topographic map was extracted from the DEM at an interval of 10 m from one another. It was observed that the elevation in the study area ranged from 19 m to 105 m with an average of 56.32 m above sea level. Hence, the parkland is regarded as a gentle slope. This study revealed that the study area...
Tree crown and tree stem diameter growth in distinction are very sensitive to competition and in ... more Tree crown and tree stem diameter growth in distinction are very sensitive to competition and in determining canopy cover. Hence, both growth variables can be used to display changes in the appearances of stands over time and health assessment. However, measurement of crown dimensions on the field remains a challenge. The main objective of this study was to develop crown diameter model for teak plantation in University of Ibadan, Nigeria and confirm their use in estimating canopy cover. Seven Permanent Sample Plots (PSPs) of size 25 m × 25 m (0.0625 ha) were randomly selected and tree growth variables measured from each plot include; diameter at breast height (DBH), total height (THT) and crown diameter (CD). The data was analysed using descriptive statistics, correlation and regression analyses. Amongst the four models were developed and evaluated for this study, Double logarithmic model with Adjusted coefficient of determination = 0.64, percentage root mean square = 5.89%, standard error of estimate =0.06 and Akaike information criteria = 333.16 gave the best fit and predictive ability. The plantation was estimated to be 84% covered by T. grandis species canopy. Therefore, it is recommended that the model can be used by forest managers for updating the stands inventory data and stocking guideline development.
Basic data and information is required if a renewable natural resource (as forest) is to be manag... more Basic data and information is required if a renewable natural resource (as forest) is to be managed in a sustainable manner. This information is largely obtained through forest inventories. It is very important in forest management since it provides the data for planning, monitoring, evaluation, research, growth and yield, timber sale as well as estimation of a removed tree characteristics. This study was carried out with aim of enlighten conservationist, ecologist and forest managers of the need to carryout assessment or inventory of flora and fauna biodiversity within our environment. This will help to ensure sustainable yield and prevent the extinction of our economic tree species and endangered animals in our forest estates. Without forest inventory, forest management would not be sustainable since there would not be sufficient information for planning and implementation. The key role of forest inventory in sustainable forest management cannot be underrated. These include; provisions of information on condition of forests, information for decision-making and management, assess site quality, timber harvests plan. For a forest and forest resources to meet the needs of the present generation without compromising the ability of future generations to meet their own needs; there is need for availability of information on forest and wildlife resources. Therefore, it is recommended, inventory should be carryout in our forest estates for ease of planning and decision-making on forest management; this is to envisage the distant future of our forest and forest products.
Crown area which is crown size, is closely related to the photosynthetic capacity of tree and it ... more Crown area which is crown size, is closely related to the photosynthetic capacity of tree and it is an important parameter to characterize biomass, leaf area and wildlife habitats. Conversely, assessment of crown dimensions still remain one of the most difficult and tedious task in forestry. The difficult measurements and the sensitivity of crown dimension on management makes it desirable to develop estimation procedures based on variables that are easier to measure than crown extension itself. The main objective of this study was to develop and observe the effects of tree slenderness coefficient in predicting crown area for <em>Tectona grandis </em>in Omo Forest Reserve. Twenty temporary sample plots of size 20 m x 20 m were randomly selected across the stand ages (9, 11, 12 and 18 years). Tree growth variables measured from each plot include diameter at breast height (Dbh) ≥ 5 cm, total height (THt) and crown diameter (CD). The data was analysed using descriptive, corr...
Journal of Research in Forestry, Wildlife and Environment, 2018
Information on tree crown is prerequisite for sustainable utilization of forest tree resources, a... more Information on tree crown is prerequisite for sustainable utilization of forest tree resources, as it is the site for physiological activities that lead to tree growth and development. Crown ratio (CR) is an index of tree stability; it indicates tree vigour and is a useful parameter for assessing forest condition. This study aimed at assessing crown ratio for improved silvicultural management of naturally grown Prosopis africana species within the University of Agriculture Makurdi, Nigeria. Nine temporary sample plots (TSPs) of size 100 m x 100 m were established using simple random sampling method. Diameter at breast height (Dbh), total height (Ht) and crown diameter (Cd) and height to live crown base (HCB) were measured for all living P. africana trees with Dbh > 10 cm within the 9 TSPs. Data collected were subjected to descriptive and bivariate correlation analysis. The trees were further classified based on their Crown ratio as high vigour (CR>0.50), moderate vigour (CR= 0...
Southern Forests: a Journal of Forest Science, 2021
Illegal logging has continued to be a major cause of depletion of the tropical forests in develop... more Illegal logging has continued to be a major cause of depletion of the tropical forests in developing countries. However, empirical means of estimating the growth characteristics of a removed tree, which will facilitate the conviction of illegal loggers in judicial proceedings, are lacking. This study aimed at developing a model that can predict individual tree slenderness coefficients (SC) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Diameter at breast height (DBH; cm), Ds (cm) and total height Ht (m) were measured from all T. grandis stands with a DBH ≥ 5.0 cm, within 35 temporary sample plots (TSPs) randomly laid out in 6 age series (26, 23, 22, 16, 14 and 12 years). The least squares regression method was used to model tree SC from Ds. Six SC-Ds models were fitted and evaluated. The relationship was best described by the single logarithmic function which gave best-fit values for the adjusted c...
Successful production of healthy seedlings in a forest nursery can be ensured through seed treatm... more Successful production of healthy seedlings in a forest nursery can be ensured through seed treatment to enhance germination. This study assessed the effects of pre-sowing treatments on the germination of Jatropha curcas; to provide the best treatment for enhancing seedling production. The experiment was laid in a completely randomized design with four treatments: (i) control (T1), (ii) soaking in; water at room temperature at room temperature for 16 hours (iii) cowdung slurry for 16 hours (iv) 98% concentrated sulphuric acid for 5 minutes Each treatment received 10 seeds and was replicated 5 times giving a total of 200 seeds sown in sterilized river bank sand. Germinated seeds were counted, converted to percentages and arsine values. The data were further subjected to analysis of variance and significant means were separated using Duncan multiple range test (DMRT) at 0.05 level of significance. The results showed that seeds with no pre-sowing treatment had the highest mean germinati...
This study examined the performance of Prosopis africana seedlings raised under different growth ... more This study examined the performance of Prosopis africana seedlings raised under different growth media. The experiment was laid in a completely randomized design with three treatments (topsoil, mixture of topsoil and poultry droppings, and mixture of topsoil and cow dung). Each treatment was replicated 4 times and each replicate had 10 potted seedlings making a total of 120 seedlings. The seedling growth variables; heights (cm) collar diameters (cm), number of leaves data were collected every 3 days for 12 weeks. The data collected were subjected to analysis of variance and significant means were separated using Duncan multiple range test at 0.05 significant level. The result showed significant difference (p=0.005) in the height of seedlings. No significant difference existed in the seedlings collar diameter (p=0.306) and number of leaves (p=0.957). The follow-up result indicated that there was no significant difference (p>0.05) in the height of seedlings raised in mixture of top...
Journal of Research in Forestry, Wildlife and Environment, 2018
Distribution of tree diameter in a specific stand provides basic information for forest managemen... more Distribution of tree diameter in a specific stand provides basic information for forest management. Little attention is given to the use of probability distribution functions in characterising the stem diameters of most Nigeria indigenous species. This study used Three-parameters lognormal and Weibull probability distribution functions in characterising the diameter of Nauclea diderrichii plantations within a restricted tropical rainforest of Nigeria for sustainable management. Thirty temporary sample plots of dimensions 20 m × 20 m were randomly laid in three age strata (42, 43 and 46 years). Stem diameters of all living Nauclea diderrichii trees with diameter at breast height ≥10.0 cm in all the sampled plots were enumerated. The performance and suitability result revealed that lognormal distribution gave superior description of the stem diameter for the Nauclea diderrichii species in the study area, with least values of Bias (0.00001), Mean absolute error (0.1214), Mean square er...
Journal of Research in Forestry, Wildlife and Environment, 2020
Potting media are important factors to the growth and development of plants. Some plants due to s... more Potting media are important factors to the growth and development of plants. Some plants due to some morphological or physiological adjustments do not attain the necessary seedling growth level expected. This study examined the influence of potting media on the early growth of Treculia africana seedlings. The seedlings were subjected to three different treatments/potting mixtures namely: mycorrhizal soil, top soil and mycorrhizal soil mixed. Each treatment was replicated five times and laid in a Completely Randomized Design. The growth variables measured weekly include; plant height (cm), collar diameter (cm), leaf production and leaf surface area (cm2). The data collected were subjected to analysis of variance and significant means were separated using Duncan multiple range test at 5% probability level. Results revealed that there were significance differences in the growth performance of Treculia africana in all the variables assessed. Seedlings grown in mycorrhizal mixed with top...
Asian Journal of Research in Agriculture and Forestry, 2020
Non-Timber Forest Products are important sources of income that can supplement farming and/or oth... more Non-Timber Forest Products are important sources of income that can supplement farming and/or other activities to the rural dwellers. In spite of this, its potential to improve the standard of living and generate income to rural dwellers has not been known in Awka-North Local Government Area. The study was carried out from January to August, 2017. The study identified the variety of non-timber forest products (NTFPs) available to rural households, the level of income generated by households from these available Non-timber forest products and constraints to Non-timber forest products collection in the study area. Three towns; Achalla, Amansea and Mgbakwu were selected using multi-stage random sampling technique. A total of 100 copies of structured questionnaires were administered to obtain information from respondents who engaged in NTFPs based activities in the selected towns. Data collected were analyzed using descriptive statistics and 5-point Likert Type Scale. The study revealed...
Institute of Forest Science, Kangwon National University, 2018
The tropical forests in developing countries are faced with the problem of illegal exploitation o... more The tropical forests in developing countries are faced with the problem of illegal exploitation of trees. However, dearth of empirical means of expressing the dimensions, structure, quality and quantity of a removed tree has imped conviction of offenders. This study aimed at developing a model that can effectively estimate individual tree basal area (BA) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six 25 m×25 m temporary sample plots (TSPs) were laid randomly in six age strata; 26, 23, 22, 16, 14, and 12 years specifically. BA, Ds and diameter at breast height were measured in all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem cross-sectional areas. Six basal area models were fitted and evaluated. The BA-Ds relationship was best described by power model which gave least values of Root mean square error (0.0048), prediction error sum of squares (0.0325) and Akaike information criterion (-15391) with a high adjusted coefficient of determination (0.921). This study revealed that basal area estimation was realistic even when the only information available was stump diameter. The power model was validated using independent data obtained from additional plots and was found to be appropriate for estimating the basal area of Tectona grandis stands in Omo Forest Reserve, Nigeria.
The type of soil, fauna and flora species that are found in an environment is affected by the ele... more The type of soil, fauna and flora species that are found in an environment is affected by the elevation characteristics of the land. However, the ability to provide techniques and model that will effectively explain the elevation patterns of protected areas will aid sustainable management of the forest and its resources. This study developed Digital Elevation Model (DEM) for Okomu National Park, Nigeria. Point coordinates (2,272) with their respective elevations were randomly obtained covering the entire study area. Interpolated natural neighbour algorithm of the Quantum Geographic Information System was used to generate Digital Elevation Model for the National Park from the elevation data. Topographic map was extracted from the DEM at an interval of 10 m from one another. It was observed that the elevation in the study area ranged from 19 m to 105 m with an average of 56.32 m above sea level. Hence, the parkland is regarded as a gentle slope. This study revealed that the study area...
Tree crown and tree stem diameter growth in distinction are very sensitive to competition and in ... more Tree crown and tree stem diameter growth in distinction are very sensitive to competition and in determining canopy cover. Hence, both growth variables can be used to display changes in the appearances of stands over time and health assessment. However, measurement of crown dimensions on the field remains a challenge. The main objective of this study was to develop crown diameter model for teak plantation in University of Ibadan, Nigeria and confirm their use in estimating canopy cover. Seven Permanent Sample Plots (PSPs) of size 25 m × 25 m (0.0625 ha) were randomly selected and tree growth variables measured from each plot include; diameter at breast height (DBH), total height (THT) and crown diameter (CD). The data was analysed using descriptive statistics, correlation and regression analyses. Amongst the four models were developed and evaluated for this study, Double logarithmic model with Adjusted coefficient of determination = 0.64, percentage root mean square = 5.89%, standard error of estimate =0.06 and Akaike information criteria = 333.16 gave the best fit and predictive ability. The plantation was estimated to be 84% covered by T. grandis species canopy. Therefore, it is recommended that the model can be used by forest managers for updating the stands inventory data and stocking guideline development.
Basic data and information is required if a renewable natural resource (as forest) is to be manag... more Basic data and information is required if a renewable natural resource (as forest) is to be managed in a sustainable manner. This information is largely obtained through forest inventories. It is very important in forest management since it provides the data for planning, monitoring, evaluation, research, growth and yield, timber sale as well as estimation of a removed tree characteristics. This study was carried out with aim of enlighten conservationist, ecologist and forest managers of the need to carryout assessment or inventory of flora and fauna biodiversity within our environment. This will help to ensure sustainable yield and prevent the extinction of our economic tree species and endangered animals in our forest estates. Without forest inventory, forest management would not be sustainable since there would not be sufficient information for planning and implementation. The key role of forest inventory in sustainable forest management cannot be underrated. These include; provisions of information on condition of forests, information for decision-making and management, assess site quality, timber harvests plan. For a forest and forest resources to meet the needs of the present generation without compromising the ability of future generations to meet their own needs; there is need for availability of information on forest and wildlife resources. Therefore, it is recommended, inventory should be carryout in our forest estates for ease of planning and decision-making on forest management; this is to envisage the distant future of our forest and forest products.
Crown area which is crown size, is closely related to the photosynthetic capacity of tree and it ... more Crown area which is crown size, is closely related to the photosynthetic capacity of tree and it is an important parameter to characterize biomass, leaf area and wildlife habitats. Conversely, assessment of crown dimensions still remain one of the most difficult and tedious task in forestry. The difficult measurements and the sensitivity of crown dimension on management makes it desirable to develop estimation procedures based on variables that are easier to measure than crown extension itself. The main objective of this study was to develop and observe the effects of tree slenderness coefficient in predicting crown area for <em>Tectona grandis </em>in Omo Forest Reserve. Twenty temporary sample plots of size 20 m x 20 m were randomly selected across the stand ages (9, 11, 12 and 18 years). Tree growth variables measured from each plot include diameter at breast height (Dbh) ≥ 5 cm, total height (THt) and crown diameter (CD). The data was analysed using descriptive, corr...
Journal of Research in Forestry, Wildlife and Environment, 2018
Information on tree crown is prerequisite for sustainable utilization of forest tree resources, a... more Information on tree crown is prerequisite for sustainable utilization of forest tree resources, as it is the site for physiological activities that lead to tree growth and development. Crown ratio (CR) is an index of tree stability; it indicates tree vigour and is a useful parameter for assessing forest condition. This study aimed at assessing crown ratio for improved silvicultural management of naturally grown Prosopis africana species within the University of Agriculture Makurdi, Nigeria. Nine temporary sample plots (TSPs) of size 100 m x 100 m were established using simple random sampling method. Diameter at breast height (Dbh), total height (Ht) and crown diameter (Cd) and height to live crown base (HCB) were measured for all living P. africana trees with Dbh > 10 cm within the 9 TSPs. Data collected were subjected to descriptive and bivariate correlation analysis. The trees were further classified based on their Crown ratio as high vigour (CR>0.50), moderate vigour (CR= 0...
Southern Forests: a Journal of Forest Science, 2021
Illegal logging has continued to be a major cause of depletion of the tropical forests in develop... more Illegal logging has continued to be a major cause of depletion of the tropical forests in developing countries. However, empirical means of estimating the growth characteristics of a removed tree, which will facilitate the conviction of illegal loggers in judicial proceedings, are lacking. This study aimed at developing a model that can predict individual tree slenderness coefficients (SC) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Diameter at breast height (DBH; cm), Ds (cm) and total height Ht (m) were measured from all T. grandis stands with a DBH ≥ 5.0 cm, within 35 temporary sample plots (TSPs) randomly laid out in 6 age series (26, 23, 22, 16, 14 and 12 years). The least squares regression method was used to model tree SC from Ds. Six SC-Ds models were fitted and evaluated. The relationship was best described by the single logarithmic function which gave best-fit values for the adjusted c...
Successful production of healthy seedlings in a forest nursery can be ensured through seed treatm... more Successful production of healthy seedlings in a forest nursery can be ensured through seed treatment to enhance germination. This study assessed the effects of pre-sowing treatments on the germination of Jatropha curcas; to provide the best treatment for enhancing seedling production. The experiment was laid in a completely randomized design with four treatments: (i) control (T1), (ii) soaking in; water at room temperature at room temperature for 16 hours (iii) cowdung slurry for 16 hours (iv) 98% concentrated sulphuric acid for 5 minutes Each treatment received 10 seeds and was replicated 5 times giving a total of 200 seeds sown in sterilized river bank sand. Germinated seeds were counted, converted to percentages and arsine values. The data were further subjected to analysis of variance and significant means were separated using Duncan multiple range test (DMRT) at 0.05 level of significance. The results showed that seeds with no pre-sowing treatment had the highest mean germinati...
This study examined the performance of Prosopis africana seedlings raised under different growth ... more This study examined the performance of Prosopis africana seedlings raised under different growth media. The experiment was laid in a completely randomized design with three treatments (topsoil, mixture of topsoil and poultry droppings, and mixture of topsoil and cow dung). Each treatment was replicated 4 times and each replicate had 10 potted seedlings making a total of 120 seedlings. The seedling growth variables; heights (cm) collar diameters (cm), number of leaves data were collected every 3 days for 12 weeks. The data collected were subjected to analysis of variance and significant means were separated using Duncan multiple range test at 0.05 significant level. The result showed significant difference (p=0.005) in the height of seedlings. No significant difference existed in the seedlings collar diameter (p=0.306) and number of leaves (p=0.957). The follow-up result indicated that there was no significant difference (p>0.05) in the height of seedlings raised in mixture of top...
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