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Research Article
Structural Characterisation of the Afzelia africana Smith ex persoon Stand in the Benoué National Park, North Cameroon
Issue:
Volume 10, Issue 1, March 2025
Pages:
1-11
Received:
30 December 2024
Accepted:
13 January 2025
Published:
24 January 2025
Abstract: Assessing and monitoring forest species is essential for implementing effective conservation strategies that support biodiversity. This study investigates the structure and growth dynamics of the Afzelia africana (A. africana) stand along the periphery of Benoué National Park (BNP) in northern Cameroon. A forest inventory was carried out at 4 sites located at the four cardinal points of the Bénoué National Park (PNB). Twelve 3000 m x 50 m transects were used, with three transects per study site. Data were collected on density, height, diameter at breast height (Dhp), crown diameter, and biological and vegetative types. To compare A. africana populations between sites, an analysis of variance (ANOVA) was used. Results indicate that wood density is higher in the northern (120 ind. /ha) and southern (90 ind. /ha) peripheries compared to the eastern (54 ind. /ha) and western (28 ind. /ha) peripheries. The distributions of trunk and crown diameters, as well as height, exhibit a bell-shaped pattern, indicating a dominance of middle-class individuals and a scarcity of both regenerating and mature individuals. This distribution suggests that the A. africana stand is under pressure, particularly in the eastern and western peripheries of the BNP. Human activities such as gold panning, charcoal production, and branch pruning, which are most pronounced in the eastern periphery, as well as agriculture and urbanization in the western periphery are contributing to plant instability and the decline of key socio-economic species like A. africana, which is also facing threats of extinction. Raising awareness among local communities and stakeholders could significantly enhance the conservation efforts for this species, particularly by focusing on the protection of juvenile plants and the most disturbed areas.
Abstract: Assessing and monitoring forest species is essential for implementing effective conservation strategies that support biodiversity. This study investigates the structure and growth dynamics of the Afzelia africana (A. africana) stand along the periphery of Benoué National Park (BNP) in northern Cameroon. A forest inventory was carried out at 4 sites...
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Research Article
Assessing the Importance of Urban Flora Structure and Traits on Carbon Stock Potential in Abomey-Calavi City in Benin (West Africa)
Soufouyane Zakari
,
Erick Senademi Sogbossi*,
Aissetou Mohamed Gobi,
Julien Gaudence Djego,
Ismaïla Imorou Toko
Issue:
Volume 10, Issue 1, March 2025
Pages:
12-26
Received:
30 January 2025
Accepted:
24 February 2025
Published:
18 March 2025
Abstract: The flora growth stock plays an important role in stabilizing the urban socio-ecological system. This study aims to assess the importance of urban flora structure and traits on carbon stock potential in Abomey-Calavi city. Stratified random sampling approach was adopted to spatially distributing the sample plots. A mixed inventory schema was used to collect floristic and dendrometric data (stem height, DBH, crown diameter) in 173 one-hectare sample plots. These data were graphically and statistically analyzed. A total of 4,390 trees belonging to 105 plant species and 31 identity groups were identified and measured. The city’s total plant primary production was evaluated at 5111.651 t of biomass, 2489.374 t of carbon, 9136.004 t of CO2 sequestered for an ecological value of US$5,816.022. The average carbon stock was estimated at (CT: 14.389 t/ha; CO2T: 52.809 t/ha; EV: 316.850 $/ha). The stock of carbon estimated in institutional zone was significantly 2.11 – 3.03 times higher than those of two other strata (p<0.0001). Stem of DBH < 65 cm concentrated 67.35% of total carbon stock versus 32.65% for those of DBH ≥ 65 cm. The significant interaction between urban strata, diameter category and species origin revealed that native species accumulated 2 times more dry matter than exotic species for the stems of DBH ≥ 65 cm. The average carbon stock of identity groups was evaluated at (CT: 1.918 ± 3.348 t/ha; CO2T: 7.038 ± 12.288 t/ha; EV: 11.123 ± 19.420 $/ha). The index of contribution was ranged from 0.052 to 1.900 for exotic species groups, compared with 0.056 to 14.441 for native species groups. Native species with single leaves, semi-caducous foliage and disseminated by zoochory stored the most carbon in the city. Strategic forest reserves should be created to conserve species with high carbon stock potential. In this way, the growing effects of heat islands could be effectively mitigated and environmental education reinforced.
Abstract: The flora growth stock plays an important role in stabilizing the urban socio-ecological system. This study aims to assess the importance of urban flora structure and traits on carbon stock potential in Abomey-Calavi city. Stratified random sampling approach was adopted to spatially distributing the sample plots. A mixed inventory schema was used t...
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Research Article
The Effects of Land Cultivation on the Spatial Distribution of the Floristic and Structural Characteristics of Woody Plant Formations in the Central West Region
Stéphane Koudougou*
Issue:
Volume 10, Issue 1, March 2025
Pages:
27-41
Received:
17 February 2025
Accepted:
26 February 2025
Published:
21 March 2025
Abstract: The diversity and structure of woody plant species will decline as the areas containing them lose the links or connections between them. This will have an impact on the structural composition and habitat diversity of woody species and does not bode well for their conservation. The objective of this research is to show the habitat types, habitat prospectivity, structural composition and species diversity of woody vegetation cover in the Centre West region (Burkina Faso). To achieve this objective, the Land Use Land Cover model and the Habitat assessment algorithm were used to generate habitat maps of woody species, and a floristic inventory was carried out to assess the structural characteristics and diversity of woody flora by land-use class. Importance value indices (IVI) and regeneration value indices (RVI) were calculated for each species. The inventory data shows that the region is made up of 69 species belonging to 55 genera in 28 botanical families. According to the IVI, the most important species are Vitellaria paradoxa (IVI=26.12), Lannea microcarpa (IVI=17.41), Detarium microcarpum (IVI=14.12) and Piliostigma thonningii (IVI=12.47). Analysis of the Shannon and Pielou indexes reveals that the agroforestry and field formations present species diversity with identical abundance, dominated by Azaderata indica, Ecaluptus, Lannea microcarpa, Parkia biglobosa, Vittelaria paradoxa and Terminalia avicinoides. These species are sometimes cut for charcoal production and to open up sown areas, while others are debarked and pruned for socio-economic purposes. The results of the habitat quality modelling show that the region is made up of primary and secondary habitat, and potential primary and secondary corridors. In 2020, primary habitat represented 38.47% of the study area. A prospective analysis of the habitat in 2050 shows a loss of connection between the primary habitats as a result of the increasing cultivation of sown areas. The prediction of biodiversity habitats in terms of the woody biological diversity found there highlights the need to preserve these habitats in the face of threats. Strategies and actions should be geared towards combating the destruction of interconnections between primary habitats and reclaiming secondary habitats and conservation corridors threatened with extinction.
Abstract: The diversity and structure of woody plant species will decline as the areas containing them lose the links or connections between them. This will have an impact on the structural composition and habitat diversity of woody species and does not bode well for their conservation. The objective of this research is to show the habitat types, habitat pro...
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Research Article
Direct Effects of Mining Activities on Land Resources Around the Pô-Nazinga-Sissili Ecological Complex in Burkina Faso
Zonata Ramdé*
Issue:
Volume 10, Issue 1, March 2025
Pages:
42-58
Received:
26 February 2025
Accepted:
8 March 2025
Published:
21 March 2025
Abstract: In Burkina Faso, protected areas have faced various pressures from local actors over the past decades, resulting in a loss of biodiversity. The PONASI ecological complex, the second-largest wildlife-oriented ecological continuum covering 327,000 hectares in the central west region of Burkina Faso, has experienced severe degradation, particularly due to mining activities. Therefore, it has become crucial to study the biophysical and biochemical impacts of mining effluents on land resources to mitigate their effects on the natural ecosystems and preserve biodiversity within the complex. This is particularly vital in ecologically sensitive areas such as the PONASI complex. Thus, SRTM images from the years 2011 were chosen and processed in order to highlight the contour lines of the environment, from which topographic profiles were drawn in order to determine the direction of the propagation of mining pollutants from the top of the slopes to the level of the lowlands. Also, Landsat satellite images from the years 2022 were processed in order to highlight the land cover units. The combination of these images made it possible to judiciously identify soil sampling sites. A total of 23 soil samples were taken, packaged in indelible bags and transported to the laboratory of the Bureau of Mines and Geology (BUMIGEB), for chemical analyses, in order to determine the levels of cyanide and mercury contained in the soils, and to study their impacts on soil fertility in the research area. The results reveal that soil degradation related to mining activities around the complex. Indeed, the analysis of soil samples in the laboratory revealed the presence of cyanide and mercury at mining sites at values higher than the WHO standard in Burkina Faso, for soil lethality to these heavy metals (<0.5mg/Kg for cyanide, and <50mg/Kg for mercury) in places. These mining pollutants used in the gold extraction process spread through the environment, leading to a reduction in soil organic matter, a decrease in the sums of exchangeable bases, a variation in hydrogen potential (PH) and a loss of soil fertility. In addition, the tracing of the toposequences crossing the mining sites have made it possible to identify the risks of runoff of these mining pollutants in the overall environment of the complex according to the topography, which could contaminate all the ecological entities of this protected area and thus degrade its biodiversity. Therefore, protective actions must be taken to ensure the conservation of biodiversity within the ecological complex.
Abstract: In Burkina Faso, protected areas have faced various pressures from local actors over the past decades, resulting in a loss of biodiversity. The PONASI ecological complex, the second-largest wildlife-oriented ecological continuum covering 327,000 hectares in the central west region of Burkina Faso, has experienced severe degradation, particularly du...
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