Sudano-Sahelian Zone Research Articles

Variability in Fruit Morphology and Germination Capacity of the Tropical Medicinal Species Securidaca longipedunculata Fres.

Securidaca longipedunculata Fresen, a medicinal tree indigenous to tropical Africa, faces threats due to root overharvesting and limited occurrence. This study assessed the extent of variation in the morphological traits and germination of seeds collected from populations located across the Sudano-Sahelian and Sudanian climatic zones in Burkina Faso. A total of 1600 mature fruits across the two climatic zones were characterized in their morphology. Seed germination tests were conducted with material collected across climatic zones, using six physical and chemical pre-treatments and two substrates. Descriptive statistics and analyses of variance were used to process the data generated. The morphological data showed significant variations in fruit and nut traits across the populations sampled, which may reflect a significant underlying genetic diversity, as expected in wild plants. Samples from the Sudano-Sahelian zone exhibited larger fruits (11.87 ± 1.38 mm) containing heavier (0.12 ± 0.04 g) and larger (5.64 ± 1.02 mm) nuts. Seeds sown on river sand exhibited the highest mean germination percentage (35.24 ± 17.73%) and germination speed (0.40 ± 0.36 seedlings per day). Seed wing and coat removal resulted in the highest mean germination percentages (respectively, 36.5 ± 19% and 35.5 ± 16%). These results suggest the existence of some barriers to germination in S. longipedunculata seeds. For seedling production, preferably heavier fruits should be collected and sowing carried out on river sand after wing or coat removal.

Impact of Climate Variability and Interventions on Malaria Incidence and Forecasting in Burkina Faso.

Malaria remains a climate-driven public health issue in Burkina Faso, yet the interactions between climatic factors and malaria interventions across different zones are not well understood. This study estimates time delays in the effects of climatic factors on malaria incidence, develops forecasting models, and assesses their short-term forecasting performance across three distinct climatic zones: the Sahelian zone (hot/arid), the Sudano-Sahelian zone (moderate temperatures/rainfall); and the Sudanian zone (cooler/wet). Monthly confirmed malaria cases of children under five during the period 2015-2021 were analyzed using Bayesian generalized autoregressive moving average negative binomial models. The predictors included land surface temperature (LST), rainfall, the coverage of insecticide-treated net (ITN) use, and the coverage of artemisinin-based combination therapies (ACTs). Bayesian variable selection was used to identify the time delays between climatic suitability and malaria incidence. Wavelet analysis was conducted to understand better how fluctuations in climatic factors across different time scales and climatic zones affect malaria transmission dynamics. Malaria incidence averaged 9.92 cases per 1000 persons per month from 2015 to 2021, with peak incidences in July and October in the cooler/wet zone and October in the other zones. Periodicities at 6-month and 12-month intervals were identified in malaria incidence and LST and at 12 months for rainfall from 2015 to 2021 in all climatic zones. Varying lag times in the effects of climatic factors were identified across the zones. The highest predictive power was observed at lead times of 3 months in the cooler/wet zone, followed by 2 months in the hot/arid and moderate zones. Forecasting accuracy, measured by the mean absolute percentage error (MAPE), varied across the zones: 28% in the cooler/wet zone, 53% in the moderate zone, and 45% in the hot/arid zone. ITNs were not statistically important in the hot/arid zone, while ACTs were not in the cooler/wet and moderate zones. The interaction between climatic factors and interventions varied across zones, with the best forecasting performance in the cooler/wet zone. Zone-specific intervention planning and model development adjustments are essential for more efficient early-warning systems.

Restoring Degraded Lands in Maroua I Municipality, Cameroon: Application of Veazcomutech Techniques

This study was carried out in the Sudano-Sahelian zone of Cameroon. It aims to contribute to the restoration of degraded land in the localities of Maroua I; to set up a sustainable soil restoration technique based on Vetiveria zizanioide- Azadirachta indica-eggshell and Musa paradisiaca peel; to evaluate the restoration of this land through the crop set up and to assess the state of the art of the "VEACOMUTECH" technique on an area of 103.5 m2. The method envisaged in this research is based on the new modern technique "VEAZCOMUTECH): Technique of V. zizanioide, A. indica, Musa paradisiaca and eggshell" with a view to restoring the fertility of the land and diversifying the population's sources of income by using this technique. The study was carried out in the Maroua I municipality on experimental plots at the Technical School of Agriculture. A control plot and a main plot treated with VEAZCOMUTECH were selected. The most vigorous species were chosen to measure growth and yield parameters over a three-week period. The results of this study show that the application of "VEAZCOMUTECH" on the site increases plant growth. In the first week, leaf length ranged from six (06) to fifteen (15) centimetres on average in the control plot. In the main plot where "VEAZCOMUTECH" was applied, leaf length ranged from ten (10) to thirty-two (32) centimetres during the same week. By the third week, leaf length had increased from 15 to 20 centimetres, while in the main plot, leaf length had increased from 32 to 80 centimetres. There was also a clear difference in the number of leaves at week three, with 20 and 87 leaves for the control and main plots respectively. The largest number of flower buds (23 flower buds) was observed on the plant in the main plot, compared with 2 flower buds in the control plot. These results could serve as a reference for the strategy of restoration and fertilization of degraded land in the Far North Region in particular and in the Sudano-Sahelian zone in general.

Adoption of agroforestry systems by smallholders’ farmers in the Sudano-Sahelian zones of Mali and Burkina Faso, West Africa

Despite the well-known potential of agroforestry systems to sustain livelihoods and ecosystem services, their targeted adoption in the Sudano-Sahelian zone of West Africa is low. To address this, we used questionnaires with 279 farmers to understand their socio-economic characteristics determining the adoption of agroforestry technologies and to record the preferred tree species in the Koulikoro region of Mali and West-Central region of Burkina Faso. The result of a binary logistic regression showed that income, off farm activities, average number of owned sheep, cooperative membership, forage security, and maintained trees and shrubs fostered the adoption of agroforestry technologies. Contrarily, the adoption of agroforestry technologies was negatively influenced by household size and crop yield. Our data show that agroforestry parklands are the most popular agroforestry technology. The most common agroforestry tree species in the study region was Vitellaria paradoxa C. F. Gaertn. The dominance of V. paradoxa within these parklands may be partly explained by the tree’s adaptation to severe drought and fire hazards, which are common to the study region. The study also revealed that smallholder farmers in Mali maintained trees on farms mainly for food security, whereas in Burkina Faso trees were mainly kept for maintaining soil fertility. We conclude that in all initiatives aimed at promoting the adoption of agroforestry in the study region, efforts should be made to consider farmers’ socioeconomic characteristics, tree preferences, and perceptions (as identified in this study).

Effects of climate on the phenology of Annona senegalensis Pers. (Annonaceae) and the distribution of associated insects in Burkina Faso.

Climate change and global warming in the Sahelian region cause dramatic drought and advancing of the desert. This phenomenon could affect the plant survival and community composition, but even for surviving plants, it could affect their phenology and the insect community associated with them. In a space-for-time approach, we studied the case of Annona senegalensis Pers. (Annonaceae), a common shrub in tropical areas, to determine the impact of climate change on its phenology and the insects associated with its flowers and fruits. We determined the phenology phases of Annona senegalensis during a 1-year period and assessed the abundance and diversity of insects in the Sudanian and the Sudano-Sahelian climatic zones of Burkina Faso. Temperature, rainfall and relative humidity were recorded during 12 months in two sites per zone. Leafing of Annona senegalensis lasted 10 months in the Sudanian zone, flowering and fruiting were 3 months long. In the Sudano-Sahelian zone, leafing lasted 8 months while flowering and fruiting were 3 and 4 months long, respectively. A total of 10,040 insects belonging to 48 species were collected in the two climatic zones. Forty-six species were found in the Sudanian zone while 25 species were recorded in the Sudano-Sahelian one. The variations in the plant phenology and the insect community were mainly due to the variation in rainfall across both climatic zones. Our results emphasize that advancing of the desert due to climate change could not only affect the survival of plants but for resistant species it also affect their interactions with insects and the whole insect community associated.

Qualitative traits and their effects on litter size and birth weight in sheep in the Sudano-Sahelian zone of Cameroon

Qualitative traits and their effects on litter size and birth weight in sheep in the Sudano-Sahelian zone of Cameroon

Diversity and Structure of Khaya Senegalensis (desr.) A.Juss Habitats Along Phytogeographical Zones in Chad (Central Africa)

In Chad, the species of Khaya senegalensis is commonly used by the local communities to treat several diseases such as malaria, fever and cough. However, the species is facing the greatest threat for the survival due to its exploitation as timber. The species is on the IUCN red list with endangered status locally. Thus, this study assessed the population structure and ecological indicators of vegetation in three climatic zones dominated by Khaya senegalensis in Chad as a basis for sustainable management and conservation strategies. A total of 88 plots (30 m x 30 m) were used in three phytogeographical zones for data collection. The structural parameters (tree density, basal area) and ecological indicators (specific richness, Shannon diversity index, Pielou’s evenness index, importance value index) were assessed for all tree species and for Khaya senegalensis following a climatic gradient. A number of 300 tree species belonging to 66 families, 11 life form and 14 chorological types were inventoried. K. senegaleensis had the highest significance value index across all three climate zones. In terms of vegetation characteristic, Sudano-Guinean and Sudanian zones were similar against Sudano-Sahelian zone which was different. These results should be fundamental for the conservation and sustainable management of K. senegalensis and its habitats specially in Chad. Likely, the findings contribute to knowledge addition for the species conservation. However, the methodological limitations related to sampling should not be obscured. Therefore, the species’ abundance areas were randomly identified while plots were placed stratified.

Analysis of the Dynamics of Vegetation in the Sudan-Sahelian Zone: Case of the Moutourwa Agricultural Production Basin, Far-North Cameroon

The Moutourwa area in the Far North region of Cameroon is facing a deterioration of its climatic conditions. In this part of the Sudano-Sahelian zone, the soils are fragile and agriculture is not very productive due to various droughts. The statistical analysis study of climatic variability based on satellitic data in the area aims to analyze the dynamics of vegetation. This involves studying the spatio-temporal dynamics of vegetation using vegetation indices. The approach adopted to carry out this study is based on the descriptive statistics of the MODIS NDVI data series from the period 2010 to 2020. The study also analyzes the VCI drought indices in this study area. It appears from these analyzes that the year 2012 has the high average and the year 2015, the lowest average of our study period with 0.51 and 0.274 respectively. The years 2010, 2011, 2013, 2014, 2017, 2018 and 2019 remained around an average of 0.3. The observation of drought indices such as the VCI examines the fluctuation of their values characteristic of the heterogeneity of the vegetation state.

Preparedness for recurrent drought disaster: insights from the Sudano-Sahelian zone of Cameroon

ABSTRACT This study examined the drought preparedness of drought-prone communities in the Sudano-Sahelian zone of Cameroon. The study employed a mixed-method approach, using qualitative and quantitative data collection methods, including interviews, household surveys, focus group discussions, and field observations. The data were then analysed using SPSS for quantitative data and content analysis for qualitative data. The results reveal that the respondents primarily rely on their personal and community abilities to prepare for droughts. A significant proportion (χ 2 = 11.676, P = 0.020) of the respondents depend on community leaders for drought information, while others rely on family and friends. They also use indigenous knowledge and construct boreholes/wells to prepare for droughts. However, limited government support, inadequate extension/scientific support services, and insufficient formal training limited drought preparedness. Age, household size, and income significantly influenced perceived preparedness for drought. Based on the findings, the study concludes that informal/locally-driven strategies are important in drought preparedness and should be strengthened. The study recommends the establishment of drought management committees at the grassroots level and the effective use of indigenous knowledge in combination with scientific knowledge for drought planning and adaptation. Given the geographical variation in climatic stressors, a focus on a specific event such as drought has enhanced the understanding of drought disaster preparedness at the community level for effective planning and policy interventions. This study contributes to the literature in the disaster preparedness discipline with a lens on community drought preparedness.

Assessment of Edaphic conditions in the Mozogo-Gokoro National Park (Sudano-Sahelian zone of Cameroon)

Vegetation health and vitality are generally dependent on soil quality. This concept particularly integrates the capacity of soils to ensure suitable conditions for plant growth. Soil physico-chemical analyses were used to make this qualitative assessment in Mozogo-Gokoro National Park. Litter and composite soil samples were collected at different depths from 0 to 150 cm in three collection units (CUs) established in the park vegetation. The results showed that throughout the park, soils have physico-chemical characteristics favourable to plant productivity, particularly in the surface horizons of the CUs, which correspond to dense to clear dry forests and gallery forests. It was particularly observed that there was an abundance of litter, good soil aggregate stability extending to depth, organic matter richness, and medium-to-high cation exchange capacities. Richness in available phosphorus, near-neutral pH water throughout the profile, textures conducive to water percolation and rooting, and absence of salt toxicity were seen as other fertility traits. However, the potential acidity and high C/N ratios confirm the fragility of these soils. These soil characteristics may also be moderately nuanced in the most savannah CU, exhibiting qualitative changes in soil samples from surface to depth. These physico-chemical attributes contrast significantly with those of natural ecosystems with degraded pedological types in the Sudano-Sahelian region, indicating a conservation of resilience in interaction with the vegetation.

Pollination and Phenological Study of Balanites aegyptiaca (L.) Del. in the Sudano-Sahelian Zone (Far North, Cameroon)

Pollination and Phenological Study of Balanites aegyptiaca (L.) Del. in the Sudano-Sahelian Zone (Far North, Cameroon)

Saving the Last West African Giraffe Population: A Review of Its Conservation Status and Management.

The West African giraffe (Giraffa camelopardalis peralta) was historically spread across much of the Sudano-Sahelian zone but is now restricted to Niger. Several factors resulted in their dramatic decline during the late 20th century. In 1996, only 49 individuals remained, concentrated in the 'Giraffe Zone'. Conservation activities implemented by the Government of Niger, supported by local communities and NGOs, facilitated their population numbers to increase. This review summarizes past and present conservation activities and evaluates their impact to advise and prioritize future conservation actions for the West African giraffe. The long-term conservation of the West African giraffe is highly dependent on the local communities who live alongside them, as well as supplementary support from local and international partners. Recent conservation initiatives range from community-based monitoring to the fitting of GPS satellite tags to better understand their habitat use, spatial movements to expansion areas, and environmental education to the establishment of the first satellite population of West African giraffe in Gadabedji Biosphere Reserve, the latter serving as a flagship for the future restoration of large mammal populations in West Africa. The integration of modern technologies and methods will hopefully provide better-quality data, improved spatial analyses, and greater understanding of giraffe ecology to inform the long-term management of West African giraffe.

Floristic Diversity and Ecological Structure of Protected Formations in the Sudano-Sahelian Zone of Cameroon: The Case of the Mayo-Kani Division

Floristic Diversity and Ecological Structure of Protected Formations in the Sudano-Sahelian Zone of Cameroon: The Case of the Mayo-Kani Division

Cameroon Climate Predictions Using the SARIMA-LSTM Machine Learning Model: Adjustment of a Climate Model for the Sudano-Sahelian Zone of Cameroon

Cameroon Climate Predictions Using the SARIMA-LSTM Machine Learning Model: Adjustment of a Climate Model for the Sudano-Sahelian Zone of Cameroon

Environmental and ontogeny effects in wood fiber properties of Pterocarpus ericaneus (Poir.)

ABSTRACT The present study examined the wood properties of Pterocarpus erinaceus, a species found in West Africa's Guineo-Sudanian and Sudano-Sahelian zones. The primarily focus was on wood fiber properties, which serve as indicators of cambial growth and the transition between juvenile and mature wood. The aim was to analyze the factors contributing to the variability of the wood fiber properties. Specifically, it examined the effect of cambial age and ecological factors on fiber properties and analyzed how the fiber properties influence density and dimensional characteristics of the wood. Measurements of fiber properties were obtained from 451 specimens collected in the Guinean, Sudanian, and Sahelian zones in Burkina Faso, Niger, and Togo. The results indicate significant variations in average fiber parameters among the three climatic zones. This variability leads to an increase in the length, width, and thickness of the fibers along the north–south decreasing rainfall gradient. However, no noteworthy correlations were observed between cambial age and fiber properties, posing challenges in distinguishing between juvenile and adult wood. In terms of correlation, the analysis shows that fiber length has no effect on physical properties, but fiber width significantly influences basic density, wood shrinkage, and the fiber saturation point (FSP).

Domestic Energy Consumption and Its Contribution to Greenhouse Gas Emissions: Insights from Koulikoro Urban Community, Sudano-Sahelian Zone of Mali in West Africa

The objective of this study is to estimate the carbon dioxide (CO2) released by domestic energy (firewood and charcoal) in the urban commune of Koulikoro, Mali. This study employed questionnaire survey to identify the type of energies used, their costs, the quantity consumed, and the difficulties of access to these energies and their impact on natural resources in Koulikoro. The consumption of each family per neighbourhood was extrapolated to its total population to determine the carbon emitted and the carbon dioxide released. Thus, the carbon dioxide emitted in tonnes per neighbourhood was determined. The findings revealed three types of energy in the urban commune of Koulikoro, mainly firewood 72%, charcoal 25% and Gas 3%. The use of these energy sources depends on accessibility and availability. The increase in consumption per district is a function of the number of people. Daily used charcoal was estimated at 2 kg day-1 and 7 kg day-1 for firewood. Overall, average firewood using was highest in largest household size and it was 62% higher than in small size category which recorded the lowest. Annual amount of charcoal used was 676 kg year-1 and 2294 kg year-1 for firewood. However, annual amount of fuelwood per person was higher in small size category and 178% greater than in largest household group than other household size. Carbon consumption per capita per year was greater in small household group estimate to be 477 kg pns-1 year-1. Thus, the urban commune of Koulikoro has a significant carbon dioxide emission and firewood emits more CO2 than charcoal.

Assessing Carbon Emissions from Biomass Burning in Croplands in Burkina Faso, West Africa

Agricultural biomass burning plays a critical role in carbon emissions, with implications for climate change. This study aims to assess carbon (C) emissions and establish C, CO, CO2 and CH4 emission factors (EFs) by simultaneously testing the effects of climatic conditions and cropland category on gas emissions. In Burkina Faso, 96 experimental fires were conducted in accordance with farmers’ operations during the land-clearing season in two climatic zones (Sudanian and Sudano-Sahelian) and across two cropland categories (Cropland Remaining Cropland (CC) and Land Converted to Cropland (LC)). The carbon mass balance technique was applied to estimate emissions. Climate zone and cropland category significantly influenced carbon emissions and emission factors (p < 0.05). The Sudanian zone recorded the highest carbon emissions (0.24 ± 0.01 t C ha−1). For cropland category, LC recorded the highest carbon emissions with an average value of 0.27 ± 0.01 t C ha−1. CO2 EFs ranged from 1661.44 ± 3.63 g kg−1 in the Sudanian zone to 1716.51 ± 3.24 g kg−1 in the Sudano-Sahelian zone. EFs showed a dependence on the cropland category, with the highest EFs in CC. Smart agricultural practices limiting cropland expansion and biomass burning need to be promoted. This study provides vital information useful for supporting decision making as part of Nationally Determined Contributions.

Social development and biodiversity conservation synergies for the West African giraffe in a human–wildlife landscape

SummaryThe West African giraffe is restricted to Niger, but historically it inhabited much of the Sudano-Sahelian zone. The population is concentrated in the ‘Giraffe Zone’ (GZ), an unprotected area with a high human population density. Since the mid-1990s, the giraffe population has steadily increased mainly due to the collective social and conservation initiatives of the government, non-governmental organizations and the local community. In 2018, the first West African giraffe satellite population was established through the reintroduction of eight individuals into Gadabedji Biosphere Reserve (GBR). In this study, we aimed to describe the current state of human–giraffe coexistence, human attitudes towards giraffe and human habits of natural resources use through a questionnaire survey conducted in the GZ and GBR. Although most of the GZ respondents highlighted crop damage caused by giraffe, we also found overall positive attitudes towards the animals. Most respondents from both sites expressed positive attitudes towards giraffe, highlighting that they do not see poaching as a major current threat. However, the giraffe population continues to be directly threatened by habitat loss through firewood cutting, livestock overgrazing and agriculture expansion. Long-term conservation of the West African giraffe is dependent on better habitat protection and understanding of current human–giraffe coexistence through ensuring that giraffe presence will benefit local communities across their range.

Climate variability impacts on growth of African grape (Lannea microcarpa Engl & K. Krause) in West Africa

Lannea microcarpa is a deciduous tree with high socio-economic value in West African agroforestry systems. While climate-growth relationships remain unknown, this species is exposed to climate extremes. Knowledge of its response to climate variations is needed for its sustainable management. Therefore, the present study aimed to examine the growth of Lannea microcarpa in two climatic zones in West Africa (Sudanian zone of Mali and Sudano-Sahelian zone of Burkina Faso) using standard dendrochronological methods. In both sites, Lannea microcarpa forms distinct growth ring-boundaries characterized by a wider band with more parenchyma cell rows and is also marked by its solitary vessels. The two standard chronologies developed were significantly correlated with the precipitation records in both Burkina Faso (r2 = 0.41, n = 30 years, p < 0.01) and Mali (r2 =0.60, n = 53 years, p < 0.001). Furthermore, a strong relationship between major seasonal precipitation (between June and September) and residual chronology was observed in Burkina Faso (r2 = 0.51, n = 28 years, p < 0.01) and Mali (r2 = 0.65, n = 52 years, p < 0.001). The formation of annual growth rings is clearly influenced by climate variability, but not all variance is accounted for. The insignificant correlation between the chronologies of the two regions may be due to various factors, including differences in climate factors and soil conditions influencing buffered water availability. Similar studies on other tree species in West Africa will be useful.

Genotype x Environment Interactions and Stability of Grain Yield of Maize Hybrids across Sudanian and Sudano-Sahelian Agro-ecological Zones in Burkina Faso

Maize is an important staple crop for millions of people in Sub-Saharan Africa and, particularly in Burkina Faso, where it ranks first among cereals since 2020. Available maize varieties are low yielding. To enhance maize production SEMAFORT, a seed company founded recently in Burkina Faso, introduced three-way hybrids. The present investigation was performed to assess 128 hybrids in 2018 and the best performing hybrids for genotype-by-environment (G×E) interactions in 2019. The study was conducted at one location (Farako-Ba) during the first year of evaluation using an alpha lattice design and in five locations during the second year using a randomized block design. The second year of the study was conducted in two different agro-ecological zones of Burkina Faso. The data were subjected to genotype and genotype by environment interaction (GGE) biplot analysis using GenStat statistical package. The analysis revealed four mega-environments which discriminated the hybrids according to yield potential. In each mega-environment, the best yielding hybrids were identified and will be further tested and possibly released for production in specific areas. The most stable genotype in the highest yielding and most stable environment was SX8-121. It could be grown across Sudan and Sudano-Sahelian zones of Burkina Faso.