Assessment of Land Use/Cover Change Using Remote Sensing and GIS Techniques: A Case of Osogbo and Its Peripheral Areas in Nigeria

The importance of accurate and timely information describing the nature and extent of land resources and changes over time is increasing, especially in rapidly growing city areas. Landsat satellite imageries of three different time periods, i.e., Landsat Thematic Mapper (TM) of 1982, 2000 and 2018 were acquired by Global Land Cover Facility Site (GLCF) and earth explorer site, quantify the changes in the Osogbo and its peripheral areas from 1982 to 2018 over a period of 36 years. These data sets were imported in ArcGIS 10.3, ERDAS Imagine and IDRIS Selva, satellite image processing softwares to create a false colour composite (FCC), supervised classification methodology was employed using maximum likelihood technique. The images of the study area were categorized into four different classes namely Core-urban, Peri-urban, Vegetation, water body. The results indicate that during the last thirty-six (36) years, Core-Urban land and water body have been increased by 2.74% (38.20 km2) and 0.98% (13.69 km2) while Peri-Urban land, and vegetation cover have decreased by 0.35% (5.00 km2), and 3.36 % (46.87 km2), respectively. The results quantify the land cover change patterns in the city and its peripheral area and demonstrate the potential of multitemporal Landsat data to provide an accurate, economical means to map and analyse changes in land cover over time that can be used as inputs to land management and policy decisions

Improving Hydrophobicity of Tropical Hardwood along Axial Positions

Wood is hygroscopic and is considered dimensionally unstable materials when exposed to wet conditions. To increase the hydrophobicity of wood, this study focused on the modification of tropical hardwood (Triplochiton scleroxylon) along different positions of the stem using acetic anhydride The weight percent gain (WPG) was determined and acetylation reaction was confirmed with FTIR. The dimensional stability of the wood was characterized by water absorption (WA), volumetric swelling (VS), anti-swelling efficiency (ASE), and water repellent efficiency (WRE). Data obtained were subjected to analysis of variance at α0.05. It was observed that the weight gain (WG) by acetylation increases along the axial position (base to top) of T. scleroxylon wood. IR-spectra confirmed properly the substitution of the acetyl group. The treatment resulted in a marked improvement in the WA and VS, ASE, and WRE of acetylated T. scleroxylon wood were also found to improve considerably from base to top of the wood. It could be said that the WPG and hydrophobicity increased, but the percentage of water absorption and volumetric swelling diminished. Hence, the modified wood showed good hydrophobicity and improved dimensional stability

Effects of Forest Fire on the Regeneration Potentials of Tree Species in Olokemeji Forest Reserve, Ogun State, Nigeria

Effects of forest fire on the regeneration potential of trees at Olokemeji Forest Reserve was established in this study. The Olokemeji fire experimental plot was selected at the reserve. The site was divided into three plots; late fire treatment was applied to Plot A, Early fire treatment was also applied to Plot B and no fire treatment at plot C (Control plot). The diameter at breast height (dbh) and tree height (m) of the tree species in the plots were assessed prior and post fire treatment. The regeneration potential of the selected plots after burning were assessed through the occurrence of saplings and seedlings obtained. The highest basal area (m2) were found in plot C followed by plot B and Plot C with mean value of 0.64, 0.55 and 0.30 m2 respectively. The number of stems per plot ranged from 25 to 67. The regeneration potentials of the three plots were found to be noteworthy. Early and late year fire regime adopted had both positive and negative effect on the regeneration potentials of tree species. This study has established the effect and relevance of fire on forest and wildlife management. It’s therefore recommended in this study that Prescribed or controlled burning should be encouraged as appropriate sivilcultural management tool for stimulating basal area growth, natural regeneration, production of tree species seedlings and saplings

Abundance, density and natural regeneration potential of trees at Shasha Forest Reserve, Osun State, Southwestern, Nigeria

Three abundance, density and natural regeneration potential of Shasha Forest Reserve were studied to ascertain their individual status within the  ecosystems. Cluster Sampling Technique was adopted for plot location in the temporary sampling areas. An area of 200 × 500 m referred to as clusters was partitioned into 200 m ×200 m tracts. The tracts were 100 m apart. Each tract was further divided into plots of 50 m × 50 m. Four of such tracts were selected for tree enumeration Sixty-six (66) tree species above >10cm dbh distributed among 28 Families were encountered. Five most abundant tree species of Strombosia postulata (38 stands), Musanga Cleistopoides (17 stands), Macaranga batteri (16 stands), Myrianthus  arboreous (13 stands) and Trichilia monadepha (10 stands) were the most dominant tree species in Shasha Forest Reserve. Rare species with only one stand were 21 in number and accounted for 31.8% of the total composition of the reserve. Five species with highest density were Strombosia postulata (13.44%) followed by Musanga Cleistopoides 5.91%, Macaranga batteri 5.56%, Myrianthus arboreous 4.66% and Trichilia monadepha 3.41% in descending order. Thirty tree species were having had density less than 1 in the ecosystem. The most common families were  Apostonaceae, Ebenaceae, Moraceae and Sterculiaceae having 6 species each and this was the most abundant followed by Euphobiaceae and Meliaceae which had 5 tree species each. Rare families within the Reserve comprised of 16 families with one stand each with 57.1% of the total tree families encountered within the Reserve. Out of 66 tree species encountered in the cluster sample, 28 species had the regeneration potential which ranged between 0.07 % and 0.01 % which is regarded as low regeneration potential. There is need to regenerate Shasha Forest Reserve through silvicultural techniques commonly referred to as enrichment planting by which desirable tree species are introduced into the ecosystem to  complement the natural  regeneration potential for sustainabilit. Keywords: Checklist, floristic composition, Tree diversity and Regeneration potentials

Evaluation of soil chemical and physical properties at the logged forest at Onigambari forest reserve

S. Soil samples were collected randomly from five locations around the forest at depth of 0- 45cm. Samples of about 500g each were collected in plastic bags and taken to the laboratory for analysis. Results presented shows that sand had the highest % in soil of the area (91.62). Bulk densities were at ranges of (1.43, 1.45 and 1.23g/cm3) at the depth of 0-15, 15-30 and 30-45 respectively. The textural classification for each depth of soil was sandy-loam. Calcium present in the soil ranges between 2.33- 2.60 which is at its lowest and cannot properly support the growth of plant. Magnesium which functions as the central core of the chlorophyll molecule in plant tissue seems to be deficient at each level of the soil depth. Therefore, if Mg is deficient, the shortage of chlorophyll will results in poor and stunted plant growth. Keywords: Decomposed, biomass, bulk density, deficien

Species enumeration and diversity of fire experimental plot at Olokemeji Forest Reserve, Ogun State, Nigeria

The fire experimental plot of a total landed area of 0.174 ha was divided into three equal parts designated Plot A, Plot B and Plot C, corresponding to the early burnt, the late burnt and the control plot, respectively. Out of the 15 species of trees identified, six species belong to Fabaceae- Mimosoideae family and other families represented are Combretaceae, Meliaceae, Lamiaceae, Rubiaceae, Anacardiaceae, Urtiaceae and Sapotaceae. Gmelina arborea was the most abundant species and it was found in plot A, B and C. The diversity indices enumerated were Dominance index, Simpson index, Shannon index or diversity index and evenness index. Plot C had the highest abundance (species count), followed by Plot A and Plot B. While Plot B depicted a high dominance, dominance was low in Plot A and lowest in Plot C. This means that a particular species was dominating Plot B, which was Gmelina arborea. This Gmelina arborea also dominated Plot A but to a lesser extent compared to Plot B. Plot C was richer in species than Plot A and Plot B. The Shannon index was low across the three plots, but considerably highest in Plot C. Evenness index was moderate at Plot C, implying that there was an even distribution of tree species in Plot C, while evenness was low at Plot A and Plot B. Comparing the present data with the older data, it is clear that the fire experimental plot has undergone deforestation over the years, which requires urgent attention and reforestation. Key words: cluster, dendogram, deforestation, burning, richnes

Biodiversity: role of non-timber forest products in food security

Biodiversity has been identified as key solution to improving food security and sustainability in the areas of food and agriculture. The global food crisis in 2008 has brought about the demand to increase food production that will feed the populations of the world which leads to utilization of other food sources other than agricultural food produce. Non-timber forest products (NTFPS) are biological materials from the ecosystem which range from plants, parts of plants, fungi, animals and animal products that are consumed either as food, condiments, spices or medicine. NTFPS have been identified to play an important role in providing primary health and nutritional needs for people living in rural areas. Their roles in ensuring food security is beyond basic consumption but is also a means of financial empowerment to people who trade in the resources and hence ability to purchase quality, safe and nutritious food at all times which is the main aim of food security.Keywords: Biodiversity, food security, non-timber food product

Marketing and utilization survey of some forest plant tubers sold in Abeokuta Metropolis

A marketing and utilization survey of some forest plants tubers sold in Abeokuta markets was conducted. Four markets were chosen namely, Itoku, Kuto, Adatan and Iberekodo with ,35, 25, 20, and 20 herb sellers respectively. Hundred percent enumerations of questionnaire were administered in the Markets. The number of respondents in Itoku, Kuto, Adatan and Iberekodo were 20, 20, 16, and 15 respectively. The survey revealed that 21 plant tubers were sold and utilized for medical purposes. The tubers are used to cure 14 ailments/disease conditons and symptoms among which are malaria, convulsion, dizziness, pile, rheumatism, cough and stroke. Due to their perishable nature, these tubers are either stored in a ventilated areas or buried in the ground. The survey also revealed that married people (48%) engaged fully in the business to support their dependants.Most of them are (55%) illiterates since the business has been associated with the aged over the years. The price of each plant tuber ranged from N10 to N50; the cost of each tuber in all the four markets were the same. It is recommended that more work be done on the contribution of these forest plant tubers to the national economy and the likely consequences of their unregulated exploitation

Assessment of environmental awareness among secondary school teachers in Ibadan metropolis

The present study is focused on the assessment on environmental awareness among secondary school teacher in some selected schools in Ibadan. Simple random sampling technique was used for the selection of sample. The investigators developed a questionnaire on assessment of environmental awareness. Statistical techniques like percentage analysis and chi square analysis were used to analyze the data. The major finding of study reveals that teachers possessed positive attitudes towards both environmental issues and environmental education. We found that contrary to a number of findings from studies in other parts of the world, male respondents were the most concerned about the environment and more knowledgeable than female individuals about environmental issues.Keywords: Environmental Education, Teacher’s Awareness, Ibada