99 research outputs found
Floristic indicators of tropical landuse systems: Evidence from mining areas in Southwestern Nigeria
No full textAbstractMost forests in the tropics have not only been reduced in size but have also experienced forest degradation. The delicate balance of the components of the forest ecosystem has been altered largely by the landuse systems which have resulted in the disappearance of some species and the introduction of new ones. In order to understand the influence of human disturbance caused by artisanal mining on plant biodiversity and the physical environment, this study assessed changes in vegetation characteristics using plant functional groups, such as invasive, pioneer and understory species. The study was conducted at two sites in two Southwestern states of Nigeria, Itagunmodi in Atakumosa West Local Government Area of Osun State and Olode in Oluyole Local Government Area of Oyo State. Complete enumerations of woody, non-woody and herbaceous plant species were carried out in 20 m by 20 m plots selected using stratified random sampling as representative of landuse classes: freshly mined (<6 months), abandoned mine (>6 months) and a control plot (secondary forest). The results showed that the control plot in Itagunmodi had undergone degradation as indicated by the presence of Alchornea laxiflora, Geophilia obvallata, Musa sapientum,Elaeis guineensis and Keetia hispida. However, if left undisturbed, it has the potential of regeneration back to its original state because of its woody tree species composition and lianas (Triclisia gilletii). In addition the forest soils in the mines had been exposed to direct insolation for a long period, and the soil structure and texture have been affected, consequently altering the viability of the seed bank. Poaceae and Papilionoideae were the most common in the freshly mined plots while invasive species were the most common in abandoned mined plots. In conclusion, the floristic composition in the mining sites has been altered and there was no clear evidence that regrowth would bring restoration of the lost ecosystem services
Assessment of Fuel and Wind Drivers of Fire Risk in Protected Mountainous Grassland of South Africa
No full textAssessment of Quality and Safety of Winged Termites (Macrotermes bellicosus) Enriched Locally Formulated Complementary Foods
No full textAddition of edible insects to local staples used as complementary foods can improve their nutrient content. Nutritional quality and safety of Macrotermes bellicosus enriched boiled rice (BR) and yam (BY) complementary foods (CFs) was assessed using rats. Macrotermes bellicosus (MB) were collected, dried, and refrigerated at -4oC. Ground MB was added to BR and BY in ratios 10.0%, 15.0%, 20.0% (w/w) to give BR1, BY1; BR2, BY2, and BR3, BY3 respectively. Nutrient content of MB, BY, BR and MB-enriched CFs were determined by AOAC methods. Nutrient bioavailability and safety of BR3 and BY3 were assessed using rats fed ad libitum for 28 days. Serum trace minerals in the CFs, control and basal diets and histopathological effects of CFs on rats’ organs were determined. Data were analysed using ANOVA at p<0.05. Dried MB contained 31.8g protein, 16.4g fat, 3.8g ash, 227.5mg calcium, 2.1mg iron, 15.0mg zinc, 330.4μg retinol equivalent (RE), and 529.0kcal energy/100g sample. The BR and BY contained 3.7-5.9g protein, 70.0-120mg calcium,4.2-5.6mg iron, 1.2-1.5mg zinc and 380- 386kcal/100g compared with 7.9-15.3g protein, 242.2-264mg calcium, 2.4-4.4mg iron, 15.1-19.8mg zinc and 357-372kcal/100g enriched CFs (p<0.05). Rats Serum trace minerals ranged between 3.4- 4.3mg zinc, 23.4-27.9mg calcium, 30.6-37.0mg iron; and 52.5-56.9μg RE, compared with control (3.2, 22.2, 34.1, 48.2) and basal (2.2, 21.1, 24.0 mg, 32.3 μg) diets respectively (p<0.05). No pathological lesions were observed in internal organs of rats on CF diets. Adding Macrotermes bellicosus to local complementary foods is safe and improved their nutritional quality, hence its use is recommended among mothers.</jats:p
Irrigation, gender and poverty: overview of issues and options
No full textIrrigated farmingLaborPovertyFarming systemsWomenFarmersIncomeHouseholdsGender
Household energy conservation behaviour: A socio-economic perspective
No full textStudies on energy conservation and household behaviour were predominantly based on econometrics using secondary data with limited studies employing the primary data. In addition, the use of secondary data from developing countries are not without their inadequacies due to missing data points. However, generating data may lead to over or under estimations which led to this study deploying structural equation model and making use of cross-sectional data from a developing country perspective. Data were collected through a structured questionnaire from 329 respondents in Akure Metropolis households, Nigeria, that were selected using a random sampling techniques. The study adopted the Partial Least Square Structural Equation Modelling approach. The results of the study showed that socio-economic variables electricity price, household size, income, number of appliance and weather have significant effects on energy conservation behavior with income having the largest structural weight. This implies that income is of utmost importance to residents` electricity saving practices as householders consume more and save less electricity with more income. It is therefore recommended that energy conservation policy should aim at regulating the purchase of electricity units at household levels, where the rich pay more tax than the poor. This will foster energy saving improvement at households sector of the Nigerian economy
Food Insecurity Status of Rural Households During the Post Planting Season in Nigeria
No full textDespite various approaches addressing the challenges of food insecurity in Nigeria, the country is still characterized by chronic food shortages particularly in the rural areas. This is an indication that the problem of food insecurity has not been adequately and critically analyzed. This study examined the food insecurity status of rural households during the post planting season in Nigeria using the recent nationally representative survey data. Results showed that about half of the rural households (49.4%) in Nigeria were food insecure during the post-planting season. Also, econometric analysis confirms that household size, education of household head, access to credit and remittances were among the major factors influencing the food insecurity status of rural households during the period. Thus, intensification of enlightenment on birth control measures, improved access to credit facilities and provision of safety nets for food insecure households during this period is pertinent
Geospatial Assessment of Forest Fragmentation and its Implications for Ecological Processes in Tropical Forests
No full textAbstract
The study assessed the patterns of spatio-temporal configuration imposed on a forest landscape in Southwestern Nigeria due to fragmentation for the period 1986 – 2010 in order to understand the relationship between landscape patterns and the ecological processes influencing the distribution of species in tropical forest environment. Time-series Landsat TM and ETM satellite images and forest inventory data were pre-processed and classified into four landuse/landcover categories using maximum likelihood classification algorithm. Fragstats software was used for the computation of seven landscape and six class level metrics to provide indicators of fragmentation and landscape connectivity from the classified images.
The result shows that although deforestation reduced between 2000 and 2010, fragmentation, however intensified during the 24 years period. Fragmentation was highest between 1991 and 2000, leading to significant landscape variability, alteration in the general biotic and abiotic conditions and exchange of material and energy. While it appears that overall forest area increased between 2000 and 2010, connectivity and biodiversity indicators declined the most during this period. The resulting scenario is that forest fragmentation, despite the control of deforestation in the last decade of this study have certainly not receded in the study area. This may continue to have subtle negative impact on exchange of material and energy in the ecosystem, contribute to increased depletion of vital forest resources and the disappearance of wildlife from previously known areas.</jats:p
Food Insecurity Status of Rural Households during the Post-planting Season in Nigeria
No full textAbout two-thirds of rural households in Nigeria are engaged in crop and livestock production as their main source of livelihood. These households are especially vulnerable to chronic food shortages owing to adverse weather and the unavailability of enough food from home production, especially during the post-planting season. This study attempts a proper empirical identification of the food insecure and the reasons for their insecurity, through a profile of food insecurity indices and an investigation of the factors influencing their status during the post-planting season in rural Nigeria. We construct food insecurity indices and specify a probabilistic model, employing the post-planting visit data of the first wave of the General Household Survey-Panel (2010). Results showed that almost half (49.4 percent) of rural households in the country were food insecure during the post-planting period. Identified key rural food insecurity determinants include: gender of household head, tertiary education of household head, access to both formal and informal credit and remittances, household size, dependency ratio and living in the North-Central, North-East, South-East and South-West Geopolitical zones of the country. Since food availability remained below the required levels for large parts of the rural populace during this season, identified food insecure households should be targeted for safety nets
Vegetation Response to Recent Trends in Climate and Landuse Dynamics in a Typical Humid and Dry Tropical Region under Global Change
No full textThe influence of global change on vegetation cover and processes has drawn increasing attention in the past few decades. In this study, we used remotely sensed rainfall and land surface temperature to investigate the spatiotemporal pattern and trend in vegetation condition using NDVI as proxy from 2001 to 2017 in a humid and dry tropical region. We also determined the partial correlation coefficient of temperature and rainfall with NDVI and the response of NDVI to changes in landcover categories due to human activities. We found that the mean annual maximum NDVI was 0.42, decreasing at a rate of 0.06 per decade. About 27.4% of the area was found to have experienced a significant negative trend in vegetation cover, while only 0.34% exhibited significant increasing vegetation vigour. Land surface temperature increased at a mean rate of 0.75°C/decade, with higher rates in agriculture, savanna, settlements, woodlands, and riparian vegetation than in forest and mangrove vegetations. Precipitation also reduced at a mean rate of 58.69 mm/decade, with higher rates in agriculture savanna and riparian vegetation than in sahelian grasslands, mangrove, forest, and woodlands. NDVI was negatively correlated with temperature in savanna, settlements, degraded forest, and sahelian grasslands providing confirmation of ongoing land degradation. It was concluded that vegetation vigour will continue to decline under rainfall and increasing temperature conditions especially in dryer regions. The use of land surface temperature in this study is particularly valuable in highlighting areas where changes in NDVI occurred as a result of synergistic action between climate and human-induced landcover changes. Our findings underscore the importance of landuse policies that account for spatial variation in synergistic relationships between the nexus of climate and land conversion processes that influence vegetation cover change in different landcover types in tropical regions
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