West African Journal of Applied Ecology

Agroecological Sustainability Assessment of Olive Farms in Semi-Arid Algeria as a Decision-Support Tool for Guiding Farmers Towards Agroecological Transition

Wed, 03 Jun 2026 00:00:00 +0000

Climate change, soil degradation, groundwater depletion and the excessive use of pesticides and fertilizers are key stress factors for agricultural systems. In this context, farmers must adopt more sustainable farming models and manage natural resources more responsibly. Several tools have been developed to assess the sustainability of agricultural systems, based on predefined indicators. One of these is the Indicators of Farm Sustainability (IDEA) method, which evaluates sustainability through 42 indicators covering agroecological, socio-territorial, and economic dimensions. In this study, the IDEA method was used to assess the agroecological sustainability of 57 olive farms in the Djelfa region of Algeria. The results show an average agroecological score of 52.74 ± 10.29 out of 100. This reflects some good practices, such as limited pesticide and fertilizer use. However, improvements are needed in plot size and crop diversification. Farms integrating small ruminant livestock (sheep or goats) achieved better results (60.52/100) compared to those without (48.19/100), highlighting the value of diversification. This method can serve as a decision-support tool to help farmers identify areas for improvement and transition towards more sustainable agricultural practices.

Tree Density and Leaf Litter as Drivers of Ground-Active Arthropod Diversity in Zoological Garden, Southeastern Nigeria

Wed, 03 Jun 2026 00:00:00 +0000

Ground-active arthropods are vital contributors to ecosystem functioning and serve as sensitive indicators of habitat quality. However, their diversity within managed wildlife environments such as zoological gardens remains poorly studied, particularly in tropical Africa. This study assessed the diversity and habitat drivers of ground-active arthropods in the Zoological Garden of the University of Nigeria, Nsukka. Arthropods were sampled using pitfall traps across four plots differing in vegetation structure, tree density, and leaf litter depth between June and September 2024. Specimens were identified to the lowest possible taxonomic level, and diversity indices including Menhinick’s Richness index (Dmg), Shannon–Wiener diversity (H′), and Pielou’s evenness (J′) were calculated. A total of 1,140 individuals representing nine arthropod orders, 16 families, and 21 species were recorded. Plots characterised by higher tree density and deeper leaf litter supported greater arthropod abundance. Exploratory regression analyses indicated positive relationships of arthropod abundance with tree density (R² = 0.90, p = 0.03) and leaf litter depth (R² = 0.96, p = 0.01). These findings highlight the importance of vegetation complexity and litter accumulation in sustaining arthropod biodiversity within zoological gardens.

Land use and Land cover Change Analysis and Its Implications for Conservation Planning in the Agumatsa Range, Ghana

Wed, 03 Jun 2026 00:00:00 +0000

Tropical montane landscapes in West Africa are undergoing rapid land-use and land-cover (LULC) transformation, with cascading effects on biodiversity and ecosystem services. This study quantified multi-decadal LULC dynamics in the Agumatsa Range, Ghana, an Important Bird Area and a critical forest-savanna ecotone, using supervised classification of Landsat imagery (1990, 2000, 2010, and 2020). Five classes (closed-canopy forest, open canopy, dense shrub/herbaceous, grassland/herbaceous, and bare surface/built-up) were outlined, yielding a Kappa coefficient of 0.86. Over 30 years, closed-canopy forest declined sharply from 51.0% to 31.0% (a net loss of 20 percentage points, 30 km²), while bare surface/built-up areas increased from 2.0% to 18.0%. Dense shrub/herbaceous cover expanded from 5.5% to 16.0%, signaling widespread secondary succession following selective logging and shifting cultivation. Change-detection maps revealed upslope retreat and fragmentation of closed-canopy forest, with the most pronounced conversion occurring between 2010 and 2020 in the highly disturbed area. These patterns align with intensified anthropogenic pressures (agriculture, road expansion, peri-urban development) amplified by climate variability. The observed degradation gradient has direct implications for biodiversity conservation. The findings underscore the urgency of landscape-scale conservation planning, including riparian buffers, enrichment planting, assisted natural regeneration, and community-based resource management (CREMAs), to reverse forest loss and sustain biodiversity in this unique hotspot.

Growth and Nutrient Uptake Response of Cocoa (Theobroma cacao (L.) Seedlings to Different Growth Media at the Nursery in Ghana

Thu, 04 Jun 2026 09:42:42 +0000

Cocoa (Theobroma cacao L.) seedlings are primarily grown in nurseries using topsoil as the main polybag medium. Some of these soils are acidic, highly weathered, and low in plant nutrients. The poor development of cocoa seedlings in nurseries has been attributed to the use of unsuitable potting media. This study aimed to assess the impact of incorporating rice husk biochar (RHB) and cocoa pod husk compost (CPHC) into soil, sawdust, and rice husk–based media on the growth and nutrient uptake of cocoa seedlings in the nursery. The experiment was laid out in a Completely Randomized Design (CRD) with three replicates. The experiment was carried out at the nursery site of Mabang Megakarya Selection programme at Mabang a substation of Cocoa Research Institute of Ghana. The treatments comprised three base-materials viz: Topsoil (TS), Rice husk (RH) and Sawdust (SD) amended with three rates of rice husk biochar (RHB) at 75%: 25%, 50%:50% and 25%:75% and two rates of cocoa pod husk-based compost (CPHC) at 90%:10% and 80%:20% (base-media: amendment on v/v). The respective amounts of media combinations were mixed thoroughly and filled into polybags with dimensions 18 cm wide x 25 cm high. Seedlings were raised from C.69 clone mixed hybrid cocoa and seedling growth was assessed at bi-monthly intervals for six months. Chemical analysis of soil and organic materials were carried out using standard laboratory procedures. At six months after sowing, results indicate that seedlings raised in TS50:RHB50 (60.3 cm) media mix were significantly (p<0.05) taller and had the highest number of leaves per plant, the highest chlorophyll content, larger leaf area and longer tap root length. Stem diameter of seedlings raised in TS90:CPHC10 media mix was bigger than in the TS100 and TS50:RHB50 mix. Cocoa seedlings grown in TS50:RHB50 media mix had the highest dry matter yield. Nitrogen uptake was significantly (p<0.05) higher in TS50:RHB50 potting media mix while P, K, Ca, and Mg were higher in TS90:CPHC10 potting media mix than in the TS50:RHB50 mix. The results indicate that the best potting mixture of soil and biochar for growing vigorous cocoa seedlings is 50% top soil mixed with 50% rice husk biochar.

Oil Palm Seedling Performance and Soil Chemical Characteristics as Influenced by Organic Fertilization Rate

Wed, 03 Jun 2026 00:00:00 +0000

Fertilizer application is a key component in the production of high-quality oil palm (Elaeis guineensis) seedlings. Inorganic fertilizers are used to supplement the native nutrient concentrations in the soil; however, their continuous application leads to soil acidification and depletion of soil organic matter. Organic fertilizers promote the growth of crops and improve soil fertility, but their effects on oil palm seedling production still remain elusive. Therefore, a two-year nursery experiment was conducted at Oil Palm Research Institute, Kusi, in the Eastern region of Ghana to determine the effects of organic fertilization rates on oil palm seedling performance and soil chemical characteristics. The experiment was arranged in a randomized complete block design with four replications. The treatments included: 25 g (T1), 50 g (T2), 75 g (T3), 100 g (T4) of organic fertilizer/seedling/month, and compared with farmers’ practice: 30 g NPK combined with Mg/seedling/month (Control, T5). Results from the study revealed that organic fertilization significantly stimulated oil palm seedling growth and improved the soil chemical properties. Compared to the control, treatment T2 increased crop growth rate by 38.18% (2022) and 27.84% (2023), total plant biomass by 18.07% (2022) and 11.90% (2023), soil total nitrogen by 44.19% (2023) and soil organic matter by 87.33% (2023). Treatment T2 can be used to replace the inorganic fertilization rate (control) to stimulate oil palm seedling growth and improve soil chemical characteristics. The application of 50 g/seedling/month of the organic fertilizer is the best application rate for producing high-quality seedlings and ensuring sustainable oil palm nursery production.

Implications of Foraminiferal Assemblages and Geochemical Proxies in the Numanha Formation, Northern Benue Trough, Nigeria

Wed, 03 Jun 2026 00:00:00 +0000

The Numanha Formation within the Yola Arm of the Northern Benue Trough represents an important Upper Cretaceous stratigraphic interval that records significant paleoenvironmental and depositional changes associated with the evolution of the West African intracontinental rift system. Despite its stratigraphic importance, detailed multiproxy investigations integrating micropaleontology and geochemistry remains limited. This study presents a comprehensive analysis of benthonic foraminiferal assemblages and major–trace element geochemistry from twelve shale samples collected from the Numanha stream section within the period of 7th -14th of May,2025 in order to reconstruct depositional environment, oxygenation conditions, sediment provenance, and basin dynamics during the Coniacian. Quantitative foraminiferal analysis reveals assemblages dominated by arenaceous benthonic taxa, particularly Haplophragmoides ssp (55.59%) and Ammobaculites ssp (35.90%), with minor occurrences of Ammotium spp, Miliammina spp, Reophax spp, and Trochammina ssp, while planktonic foraminifera are completely absent. Geochemical analyses done using the VANTA Portable XRF machine reveal elevated concentrations with mean values such as Si>128, 862, Al>57, 004, Fe>52, 125, Ti>5, 090, K>4, 995, Zr>332 and indicating a moderate to strong influx of terrigenous material. In contrast, the enrichment of Ni>94.4, V>76.77, and Mo>3.62 suggests intermittent dysoxic to suboxic bottom water conditions. When integrated with micropaleontological evidence, these geochemical proxies suggest that deposition occurred within an inner-neritic to marginal marine shelf environment. This setting was likely characterized by high sediment supply, restricted water circulation, and episodic marine transgressions. The combined dataset supports a depositional model involving a proximal mud-dominated shelf developed during the Coniacian transgressive–regressive cycle within the Northern Benue Trough. These findings contribute to improved paleoenvironmental reconstruction, sequence stratigraphic interpretation, and evaluation of source-rock potential in the Upper Cretaceous succession of the Yola Arm.

Validation of Non-destructive Techniques for Estimating the Age and Growth of Polylepis tarapacana in the High Andes of Northern Argentina

Wed, 03 Jun 2026 00:00:00 +0000

Accurately determining the age of trees is fundamental for ecological and conservation studies, particularly for slow-growing, threatened species in extreme environments. This study evaluates the effectiveness of a non-destructive technique for estimating the age of apical branches and analyzing the growth of Polylepis tarapacana, a near-threatened tree species that forms the world's highest forests and shrublands in the Argentine Altiplano. The technique relies on counting the external bud marks (scars) left by annual shoots on apical branches. To validate this method, we collected 48 apical branches from across the species' distribution in Argentina. The age estimated from bud mark counts was correlated with the age determined by annual ring counts on cross-sections. Statistical analysis revealed a highly significant positive correlation between the two methods (Spearman's ρ = 0.820, p < 0.001), with a coefficient of determination of R² = 0.672. The overall mean absolute error of the non-destructive technique was 1.11 years. Accuracy varied with age, showing higher relative error in very young branches (1-3 years) but high reliability (relative error of 8.5%) for branches over 13 years old. Furthermore, growth analysis indicated a significant decrease in annual shoot elongation with increasing age, with a reduction observed between the youngest (1-3 years) and oldest (10-12 years) age groups. These results demonstrate that the bud mark counting technique is a statistically valid, accurate, and robust non-destructive method for age estimation in young apical branches (up to ~25 years) of P. tarapacana. Its application provides a valuable tool for demographic monitoring and conservation strategies for this high-altitude species, enabling growth assessment without damaging vulnerable populations.

When Rainfall Dictates the Ride: Exploring the Impact of Rainfall on Mobility in Accra

Wed, 03 Jun 2026 00:00:00 +0000

The rapid urbanisation in Sub-Saharan Africa poses significant challenges to peri-urban transport systems, especially amidst escalating climatic events. This study examines the impact of recurrent heavy rainfall events and associated flooding on transport infrastructure and commuters’ choice of transportation modes in peri-urban areas of Accra, Ghana. Using data from a comprehensive mobility survey and qualitative interviews, the study examines the state of road infrastructure and its effects on daily mobility. The findings reveal that poor road conditions, exacerbated by heavy rainfall, limit the availability and reliability of transport options, compelling residents to rely on motorcycles and other less conventional modes for part of the entire trip. This paper highlights the interaction between inadequate transport infrastructure and rainfall-induced disruptions, demonstrating how these factors collectively shape transportation choices in peri-urban areas. Our findings underscore the urgent need for sustainable urban planning and flood-resilient transport systems to improve mobility and environmental resilience in rapidly urbanising regions. The study contributes to existing research by providing empirical evidence on the mobility challenges faced by commuters in flood-prone regions of Sub-Saharan Africa.

Physico-Chemical Quality and Heavy Metal Assessment of Surface Water Sources in Artisanal Mining Communities in Mpohor Wassa East District, Ghana

Wed, 03 Jun 2026 00:00:00 +0000

This study evaluated the physico-chemical characteristics and concentrations of heavy metals present in the surface water sources that were affected by artisanal mining activities within the Mpohor Wassa East District in Ghana. To determine the key factors that most significantly affect the variability of water quality, multivariate statistical methods, such as the Principal Component Analysis (PCA), were used. Except for turbidity, all measured physico-chemical parameters complied with World Health Organization (WHO) guidelines for drinking water. PCA revealed six principal components, with the first component (PC1) accounting for 22.5% of the total variance. PC1 was strongly associated with cobalt (Co), chromium (Cr), copper (Cu), arsenic (As), and cadmium (Cd), and moderately associated with nickel (Ni), zinc (Zn), mercury (Hg), magnesium (Mg), lead (Pb), and iron (Fe). These results are important in the informative design of both location-specific surface water monitoring and management plans in Ghana's artisanal mines.