Social and Environmental Forestry
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Item Geodatabase and Health Risk Assessment of Avenue Trees on Selected Roads in a Tertiary Institution in Ibadan, Nigeria(Joint Coordination Centre of the World Bank assisted National Agricultural Research Programme (NARP), 2024) Israel, R.; Akintunde-Alo, D. A.; Mshelia, Z. H.; Oluwajuwon, T.V.Campuses of Nigerian universities, especially the older ones, are home to aged trees that were originally planted for environmental beautification and aesthetics. However, due to the current global climate change and increased vulnerability to abiotic and biotic stressors, the old trees could pose threats to pedestrians, structures, and roads within the university campus environments. Therefore, the objective of this paper is to develop a geodatabase and evaluate the health risk assessment of avenue trees on selected roads in a tertiary institution in Ibadan, Oyo State, Nigeria using appropriate standard methods. Results obtained reported a total of 121 individual avenue trees belonging to 14 species along the study roads. The geospatial distribution analysis revealed that Emotan road had a lower density of avenue trees compared to Benue and Oduduwa roads. Furthermore, the health risk assessment indicated that 17.35% of the individual avenue trees had defects, posing potential hazards and risks of tree failure, and potential damage to pedestrians, vehicles, and neighboring utilities. The developed geodatabase is user-friendly and allows for easy data storage and quick information retrieval on the avenue trees, enhancing their maintenance and risk management. Furthermore, this study shows that systematic replacement, replanting, and management of avenue tree species could be a proactive initiative for the expansion of the geodatabase and to reduce negative health impacts.Item Assessment of land surface temperature and factors influencing urban green space dynamics in Sapele, Delta State of Nigeria(Faculty of Agriculture, Usmanu Danfodiyo, Sokoto, Nigeria, 2024) Akintunde-Alo, D. A.; Joy, A.; Komolafe, O.O.Forest is a carbon sink contributing to the tropical Land Surface Temperature (LST) changes. However, information on the nexus between Urban Green Space (UGS) and LST of most cities is limited. Therefore, spatiotemporal variability in UGS and LST, and factors affecting UGS dynamics were examined in Sapele, Delta State, Nigeria. Landsat imageries of 2002, 2012, and 2022 were obtained and classified using Iso Cluster Classification with point pixel-based correction for accuracy improvement. The LST was extracted from the imageries. Relationship between NDVI and LST was established using R. Structured questionnaire was used to elucidate information on factors affecting UGS (FAUGS); population growth (PG), lack of law enforcement (LLE), demand for timber (DT), agricultural expansion (AE), overgrazing (O), soil characteristics (SC), urban sprawl (US) and lack of land tenure system (LLTS), using logit regression at α=0.05. Four LULC were identified; UGS, water bodies, bare land, and built-up areas. The UGS decreased from 88.55% in 2002 to 81.83% in 2022, built-up area expanded from 4.64% to 12.55%. Highest mean LST (27.46°C) and lowest NDVI (0.54) were recorded in 2012, least LST (26.46°C) and highest NDVI (0.69) were recorded in 2002. Negative nexus was observed between NDVI and LST for 2002 (-0.453), to 2022 (-0.393). The odd ratio showed that PG (1.2x108), US (13.8), and LLTS (3.0) significantly affected UGS dynamics with the regression model (FAUGS) = -9.7 + 18.6(PG) – 8.0(LLE) - 23.61(DT) - 18.5(AE) -10.8(O) - 25.7(SC) + 2.6(US) + 1.1(LLTS). This study affirmed that urban green space was affected by urbanization.Item Optimising Sampling Design with Semivariogram for Vegetation Survey of Derived Savannah, Ogun State, Nigeria(unique scientific publishers, 2024) Banjo, O. B.; Akintunde-Alo, D. A.; Ige, P. O.Vegetation survey is useful for biodiversity conservation and management. Sampling design strategies oftentimes fail to capture the heterogeneous vegetation structure of area being studied due to cost and time constraint. The study aimed to determine the optimum sampling design for vegetation assessment in the study area by characterizing spatial structure and identifying extent of spatial correlation in data points. Hypothetical sampling scenarios of low, medium and high density random and transect sample plots of (3 x 3 km) were laid on Normalised Difference Vegetation Index (NDVI) from Landsat 8 Operational Land Imager (OLI) satellite imagery of the study area. NDVI values were extracted for the respective sampling scenarios. Data were subjected to descriptive statistics and fitted to spherical, exponential and Gaussian’s semivariogram models. Best fitted models were evaluated by Root Mean Square Error (RMSE) values. Nugget, sill and range parameters of the best fitted semivariogram models described the spatial structure of the vegetation cover in the study area. Therefore, the parameter estimates guided the selection of medium density random sample plots and low density transect-laid sample plots as the optimized sampling design most suitable for vegetation survey in derived savannah ecosystem of Ogun State, Nigeria.Item Stand growth, Biomass and Carbon sequestration potentials of Parkia biglobosa (jacq.) Bench plantation in South-Western Nigeria(Joint Coordination Centre of the World Bank assisted National Agricultural Research Programme (NARP), 2024) Akintunde-Alo, D. A.; Onilude, Q. A.; Ige, P. O.; Adeoti, O. O.This study assessed tree growth variables, above (AGB), below ground biomass (BGB) and total carbon content (TC) sequestered by Parkia biglobosa (Jacq.) Bench. Plantation in Wasangare, Oyo State using nondestructive ground base survey. Tree growth data (Diameter at breast height, Dbh and Tree height, Th) were collected using lacer ace hypsometer and diameter girth tape from 20 temporary sampling plots of size 25 m X 25 m established through systematic transect lines. Diameter size classes (DSC) for the plantation was examined, carbon stock for each DSC was also determine while basal area (m2 ha-1), volume (m3 ha-1), Biomass (Mg ha-1) and Carbon (Mg ha-1) were also estimated. Results showed mean Dbh of 18.7 + 0.25 cm with 8.14 + 0.10 m, 0.033 + 0.00 m2 ha- 1 and 0.320 + 0.01 m3 ha-1 for tree height, basal area and volume respectively. AGB and BGB were 10.877 + 0.39 Mgha-1 and 2.175 + 0.08 Mgha-1 respectively while TC was 6.527 + 0.24 Mgha-1. The percentage carbon stock proportion for each DSC revealed class size 25-29-9 cm (19.02%) as the highest while the least proportion was observed in less than 5 cm class with 0.04% of carbon. The DSC showed majority of the tree Dbh in lower Dbh classes with fewer trees in higher classes forming almost a normal bell shape. The study provides information that can help the management in planning silvicultural activities and selective removal from the stand (harvesting schedule). Tree Dbh, height, basal area, volume and biomass are the determinant characteristics for forest carbon assessment. In conclusion, the plantation actively sequesters carbon showing potentials for indigenous trees in climate change mitigation.Item Geospatial assessment of climate sensitivity in Ibarapa North, Oyo State, Nigeria(Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto, Nigeria, 2024) Agbor, C.F.; Akintunde-Alo, D. A.; Ogunwale, O. R.This study employed remote sensing and geographic information system (GIS) to evaluate the spatial pattern of carbon(iv)oxide (CO2) concentration and the resulting climate sensitivity in Ibarapa North local government areas of Oyo State, Nigeria. The evaluation was carried out using Landsat images of 2003 and 2023, digital elevation model, as well as CO2 data collected with CO2. meter. Surface temperature and radiative forcing were generated from the satellite images using random forest algorithm in 𝑅 software environment, while the climate sensitivity was evaluated using Drakes’ Sensitivity Linear Model. The results revealed mean air temperature of 31.5oC and 32.7oC in 2003 and 2023 respectively. The area experienced positive radiative forcing mean value of about 2.69𝑊 𝑚−2, which indicates more energy being trapped on the earth’s surface that could cause warming. The climate sensitivity in 2023 was 0.4oC 𝑚−2s-2 which falls below global average of about 3oC 𝑚−2s-1. The CO2 concentration was extrapolated based on the mathematical function derived from the regression function between the variable and elevation. The results revealed positive radiative forcing and low climate sensitivity value. This may seem positive, but that doesn’t negate the need for action to mitigate adverse effects of climate change.Item Land Use Land Cover Dynamics of Oba Hills Forest Reserve, Nigeria, Employing Multispectral Imagery and GIS(Scientific Research Publishing, 2023) Bukoye, J. A.; Oluwajuwon, T. V.; Akintunde-Alo, D. A.; Offiah, R. I.; Ogunmodede, M. E.Land use Land cover (LULC) has undergone progressive changes worldwide over the years. However, there is limited information available about these changes in Oba Hills Forest Reserve, Nigeria. The existing spatial analysis of the forest excluded important land use classes like settlements. Therefore, this study aimed at assessing the dynamics of LULC in Oba Hills Forest Reserve between 1987 and 2019. Images from Landsat 5, Landsat 7, and Landsat 8 for the years 1987, 2001, 2013, and 2019 were obtained and subjected to preprocessing and classification using the maximum likelihood algorithm, change detection, and Normalized Differential Vegetation Index (NDVI). The coordinates of specific benchmark locations and other points were acquired for ground-truthing and developing Digital Elevation Model (DEM). Three distinct LULC classes were identified: forest, bare land (including open spaces, agriculture, rocks, and grasslands), and built-up areas. The forest cover in the reserve gradually decreased from 56% in 1987 to 47% in 2019, resulting in a total area loss of 455.4 hectares. Correspondingly, the other LULC classes experienced exponential expansion. Bare land increased from 44% in 1987 to 52% in 2019, while the built-up area expanded by 57.28 hectares. These changes are attributed to prevalent anthropogenic activities such as agriculture, grazing, logging, firewood collection, and population growth within the catchment area. The declining NDVI values in the forest reserve, from 0.52 to 0.44 within the years of assessment, further substantiated the substantial loss of forest cover. The DEM and topographical map highlighted notable steep slopes and elevations of up to over 550 m above sea level (asl) within the reserve, which have implications for forest growth and dynamics. In conclusion, this study reveals extensive rates of forest cover changes into bare land, primarily for agriculture, and settlements, and offers further recommendations to reverse the trend.Item Evaluation of height-diameter models for community Parkia biglobosa Jacq B. plantation in wasangare, Oyo State.(Northeast Forestry University and the Ecological Society of China in collaboration with Springer Verlag., 2023) Onilude, Q. A.; |Ige, P.O.; Alo, A.A.Forest growth and yield models are fundamental tools for sustainable forest management planning and future inventory assessments. In order to quantify the growing stock of Parkia biglobosa in Wasangare, Oyo state, reliable height-diameter (H-D) models are required. Therefore, the aim of this study was to evaluate 2-parameter H-D models for the prediction of heights of Parkia biglobosa tree which are consistent with current forest management practices in the country. Measured 1,196 pairs of height and diameter data were subjected to six (6) 2-parameter H-D models viz Naslund, Meyer, Curtis, Modified Log Logistic, Michaelis-Menten and Wykoff. Model fitting and validation was done in ratio 75:25. With the use of R software tools, the fitting and validation was done. Root mean square error (RMSE), mean absolute bias (MAB), Akaike information (AIC) and Bayesian information criterion (BIC) were used to assess the models. The result showed that all the models were significant but based on the goodness-of-fit statistics, Meyer H-D model had the least rank value, followed by the Modified log logistics H-D (M. LogL) model. The Meyer H-D model had RMSE, MAB, AIC and BIC of 2.996, 2.389, 4520.263 and 4524.660 respectively while M. LogL HD model had 2.999, 2.421, 4522.082 and 4536.480 respectively. Therefore, it was concluded that Meyer H-D model and M. LogL model written as and, respectively were selected as the best candidate models for H-D relationships of Parkia biglobosa plantation especially in the savanna zone of Oyo state.Item Geospatial Assessment of Akure Forest Reserve in Ondo State, Nigeria(Forests and Forest Products Society, 2022) Alo, A. A.; Komolafe, O.O.Land Use Land Cover (LULC) changes is one of the significant factors that determines the interaction between humans and its environment in the tropics. In Nigeria, the effect of these anthropogenic activities has led to deforestation and consequent degradation. However, there is dearth of information on the dynamics of many forests cover in Southwestern Nigeria, especially in Akure Forest Reserve. Therefore, this study aimed at assessing the LULC change of Akure forest reserve. Landsat imageries (5 TM of 1984, 7 ETM+ of 2000, and 8 OLI/TIRs of 2016 and 2021were obtained and processed. The processed imageries were analyzed using supervised Maximum Likelihood Classification algorithm to determine LULC classes of Akure forest reserve. The LULC classification followed Anderson darling categorization. Five LULC classes were used: Dense Forest (DF), Less Dense Forest (LDF), Built‐Up (BU), Bare Land (BL) and Water Bodies. Normalized difference Vegetation Index (NDVI) was used to determine the greenness of the reserve. Dense Forest has drastically reduced from 82.6% observed in 1984 to 26.41% in 2021, indicating high level of forest deforestation and degradation, while an upsurge was observed in LDF from 1984 (14.19%) to (55.03%) in year 2021. Changes in BU fluctuated between 0.51% in 1984 and 3.16% in 2021. The highest (0.4) and lowest (0.3) NDVI were recorded in 2016 and 2000. Dense forest cover in Akure Forest Reserve has been converted to agricultural activities. Therefore, there is need for conservation of the forest resources to preclude depletion.Item Aboveground biomass allometric models for a private semi-natural forest in Nigeria(AJOL (African Journal of Open Libraries), 2023) Alade, A.A.; Oluwajuwon, T.V.; Alo, A. A.; Ogana, F.N.; Aghimien, E.VPrivate forests with conservation priority such as Abayomi Farm Estate (AFE) Emerald forest reserve, Nigeria can significantly contribute to the global carbon cycle while enhancing sustainable livelihoods. However, little consideration is given to accounting for their biomass pools and carbon sequestration. This study, therefore, developed models for estimating aboveground biomass in the private semi-natural forest. Four (4) temporary sample plots (TSPs) of 50 x 50 m were systematically sampled with a complete, non-destructive enumeration of 176 individual tree species with a diameter at breast height (DBH) > 10 cm. Aboveground biomass models were developed using the enumerated parameters covering a wide range of DBH and total height (H), as well as wood density (WD) as predictor variables. The models were developed for the two most-abundant, native tree species and all species combined in the forest. The models were evaluated using different indices such as coefficients of determination (R2), root mean square error (RMSE). Selected models were cross-validated. The species-specific biomass models with double predictors proved more accurate and reliable for estimating aboveground biomass in the forest than the DBH-only allometry, with their adjusted R2 as high as 95 % and RMSE < 0.23. Mixed-species allometry fitted by all the three predictors (DBH, H and WD) was the most suitable, depicting the added relevance of wood density and sample size in biomass modelling. It recorded RMSE and adjusted R2 of 0.22 and 97 %, respectively. Overall, all the models provided good estimates and could be used for assessing the carbon storage in the forest estateItem Spatio–Temporal Variation of Chlorophyll, Nutrients and Productivity in Lagos Lagoon, Lagos Nigeria Using Remote Sensing Approach(Sciencedomain International, 2022) Adewoyin, J. E.; Olaifa, F. E.; Alo, A. A.; Kappo, A.; Muibi, K. H.Spatio–temporal variation in Chlorophyll, Nutrients and Primary Productivity of some selected sampling stations in Lagos lagoon were investigated using conventional method from November 2019 to July 2020, in order to compare the result with data from satellite image using MODIS Aqua. Global Positioning Receiver was used to capture the geographic coordinates of the sampling stations. Water sampling was carried out monthly using standard methods during wet and dry seasons. The observed data were subjected to statistical analysis using Microsoft Excel and SPSS. version 20. In wet season, the highest mean value for Chlorophyll a (1.15±0.02 μg/L) was recorded in Ofin while the lowest values (0.06±0.01 μg/L) was observed in Okobaba. During the dry season, the highest mean value (0.75±0.10 μg/L) was in Ofin while the lowest mean value (0.27±0.0.08 μg/L) was recorded in Ibeshe. The MODIS satellite variation in chlorophyll-a showed that the highest value of highest recorded value (1.37±0.00 μg/L) was in wet season (Ijede) while the lowest value (0.12±0.01 μg/L) was observed in dry season (Okobaba). The highest transparency value (0.97±0.01 mg/L) was recorded in dry season (Ofin) while the lowest value (0.35±0.25 mg/L) was recorded in wet season (Oworonsoki). The highest mean value of Surface Sea temperature was recorded in the dry season of Apapa (30.28±1.15oC) while the lowest mean value (26.41±1.15oC) was observed in Okobaba in the wet season. The chlorophyll-a concentration analyzed using standard method and MODIS satellite, in both dry and wet seasons in the sampled stations differ greatly from one another in terms of the mean concentration. The primary productivity of Lagos Lagoon was relatively low, with no significant spatial variations between sampling stations. The results of sea surface temperature, transparency and chlorophyll ‘a’ estimation from the MODIS revealed that the values were positively correlated with laboratory result with r2-value of 0.67, 0.80 and 0.77. This indicates that MODIS data and laboratory results generated for Lagos Lagoon were positively related.