Analyzing the Contribution of Cameroon’s Council Forests to Climate Change Mitigation and Socioeconomic Development

Council forests were officially enacted in Cameroon in 1994 as part of the forestry law reform. The law provided rural councils with the legal right to create their own forests estate within the Permanent Forest Estate (PFE) of the State, following the preparation of a management plan approved by the forest administration. In this chapter, we analyze the socioeconomic and climate change mitigation potentials of these forests and propose possible options for improving their socioeconomic importance as well as their ability to mitigate climate change. Results indicate that Cameroon’s council forests provide socioeconomic opportunities to communities in which they are located including employment and revenue from the sale of timber and nontimber forest products emanating from these forests. Additionally, given their diversity in terms of the various forest types (e.g., humid dense evergreen forests, humid dense semideciduous forests, and gallery forests), these forests have enormous carbon stocks which can provide huge opportunities for international climate initiatives such as the REDD+ mechanism to be initiated within them as a potential for mitigating global climate change. The chapter identifies and discusses possible options for improving the socioeconomic and climate change mitigation potential of these forests. Progress on the options the chapter opines, will help in improving the contributions of these forests to socioeconomic development and climate change mitigation

Multiscale análisis of heavy metal contents in Spanish agricultural topsoils

This study characterized and mapped the spatial variability patterns of seven topsoil heavy metals (Cr, Ni, Pb, Cu, Zn, Hg and Cd) within the Ebro river basin (9.3 million ha) by Multivariate Factorial Kriging. The variograms and cross-variograms of heavy metal concentrations showed the presence of multiscale variation that was modeled using three variogram models with ranges of 20 km (short-range), 100 km (medium-range) and 225 km (long-range). Our results indicate that the heavy metal concentration is influenced by bedrock composition and dynamics at all the spatial scales, while human activities have a notorious effect only at the short- and medium- range scale of variation. Sources of Cu, Pb and Zn (and secondary Cd) are associated with agricultural practices (at the short-range scale of variation), whereas Hg variation at the short- and medium-range scale of variation is related to atmospheric deposition

Looking back and moving forward: 50 years of soil and soil fertility management research in sub-Saharan Africa

Article purchased; Published online: 02 Nov 2017Low and declining soil fertility has been recognized for a long time as a major impediment to intensifying agriculture in sub-Saharan Africa (SSA). Consequently, from the inception of international agricultural research, centres operating in SSA have had a research programme focusing on soil and soil fertility management, including the International Institute of Tropical Agriculture (IITA). The scope, content, and approaches of soil and soil fertility management research have changed over the past decades in response to lessons learnt and internal and external drivers and this paper uses IITA as a case study to document and analyse the consequences of strategic decisions taken on technology development, validation, and ultimately uptake by smallholder farmers in SSA. After an initial section describing the external environment within which soil and soil fertility management research is operating, various dimensions of this research area are covered: (i) ‘strategic research’, ‘Research for Development’, partnerships, and balancing acts, (ii) changing role of characterization due to the expansion in geographical scope and shift from soils to farms and livelihoods, (iii) technology development: changes in vision, content, and scale of intervention, (iv) technology validation and delivery to farming communities, and (v) impact and feedback to the technology development and validation process. Each of the above sections follows a chronological approach, covering the last five decades (from the late 1960s till today). The paper ends with a number of lessons learnt which could be considered for future initiatives aiming at developing and delivering improved soil and soil fertility management practices to smallholder farming communities in SSA

Differentiated Neogene bauxitization of volcanic rocks (western Cameroon): morpho-geological constraints on chemical erosion

Published online: 30 May 2020Lateritic weathering of Miocene volcanic rocks from western Cameroon highlands formed duricrusted bauxitic profiles. Two weathering profiles on ca. 14 Ma basalt and ca. 16 Ma trachyte were studied using geochemical mass balance functions. Less mobile elements Ti and Zr were used as references to quantify volumetric change (strain, ε), element transfer rate (τ) and geochemical mass transfers during the bauxitization process of basalt and trachyte. Conversion of parent rocks to kaolinite and goethite rich saprolites evolved to Al-Fe rich bauxites, mostly composed of gibbsite and iron oxy-hydroxides (goethite and hematite). However, formation of Al-Fe bauxitic profiles required higher Si leaching on trachyte than on basalt. Our results document that chemical weathering of a larger thickness of trachyte than basalt has been required to form a unit meter of weathering profile, implying differential rates of rock chemical erosion and topographic decay of landscapes. Rates of chemical erosion and formation of lateritic weathering profiles in western Cameroon have been mostly controlled by drainage conditions and volcanic rocks composition (mostly SiO2 content differences), that also resulted in contrasted landscapes evolution during the Neogene

Differentiated Neogene bauxitization of volcanic rocks (westernCameroon): Morpho-geological constraints on chemical erosion (vol 194,104685, 2020)

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Growth response of Moringa oleifera Lam. as affected by various amounts of compost under greenhouse conditions

The study was carried out to assess the effect of domestic animal composts on growth performance of potted moringa. The study was conducted in the greenhouse for 55 days. Various quantities of composts (100–300 g) added to 800 g of soil were applied. A Randomized Complete Block Design (RCBD) with 14 treatments (each of which was replicated 12 times) was used, giving a total of 168 experimental units. Plant height, stem diameter, leave length and number of leaves were assessed for each treatment. Results indicate that cow dung compost (100 g, 200 g and 300 g) significantly increased the stem diameter of moringa by respectively 33.09%, 33.09%, and 29.93 as compared to that of the control 55 days after in the greenhouse. An increase in the number of leaves by 48.54% due to application of 100 g cow manure compost was observed after 40 days compared to the control. There were significant differences between treatments effects (p < .05) on all the parameters. Organic amendments in general and cow dung compost in particular could constitute the best fertilizer to improve growth moringa in pots

Distribution of duricrusted bauxites and laterites on the Bamiléké plateau (West Cameroon): Constraints from GIS mapping and geochemistry

International audienceEstimation of the mineral resources potential is an important issue for most of developing countries. The spatial distribution of bauxites and lateritic land surfaces on the Bamiléké plateau (West Cameroon) has been investigated with a Boolean modeling process into a GIS environment on the basis of geological constraints such as elevation, rock and soil types, and landscape morphology. Field observation and SRTM (Shuttle Radar Topographic Mission) data allowed the differentiation of two lateritic land surfaces separated by a minimum altitude difference of about 60 m. These surfaces constrained by favorable rock types, slope steepness and soil types provided a potential lateritic bauxitic area of 381 km 2 (17.2% of the total study site). Field validation and the integration of legacy spatial data resulted in an area of 60.1 km 2 for potential bauxitic ores, i.e. obviously duricrusted bauxitic surfaces (with 47.8 km 2 in the upper surface and 12.3 km 2 in the lower surface). Alumina contents obtained from duricrust samples were analyzed by geostatistical methods and classical kriging interpolation to discriminate between bauxitic and ferruginous laterites. This highlighted a geochemical trend from higher alumina values on the upper surface (40–66 wt.%) to lower values on the lower surface (13–44 wt.%). Finally, our study documents two duricrusted lateritic surfaces arranged in a staircase manner and having different geochemical characteristics. The total bauxitic-rich surface is distributed in five spots throughout the study area and covers 56.2 km 2 , while ferruginous laterites occupy a spot of 3.9 km 2. GIS mapping approach of lateritic land surfaces, accounting for reliable constraints, might be promising for larger scale investigations of mineral resources in Cameroon

Towards a harmonisation of the soil map of Africa at the continental scale

In the context of major global environmental challenges such as food security, climate change, fresh water scarcity and biodiversity loss, the protection and the sustainable management of soil resources in Africa are of paramount importance. To raise the awareness of the general public, stakeholders, policy makers and the science community to the importance of soil in Africa, the Joint Research Centre of the European Commission has produced the Soil Atlas of Africa. To that end, a new harmonised soil map at the continental scale has been produced. The steps of the construction of the new area-class map are presented, the basic information being derived from the Harmonized World Soil Database (HWSD). We show how the original data were updated and modified according to the World Reference Base for Soil Resources classification system. The corrections concerned boundary issues, areas with no information, soil patterns, river and drainage networks, and dynamic features such as sand dunes, water bodies and coastlines. In comparison to the initial map derived from HWSD, the new map represents a correction of 13% of the soil data for the continent. The map is available for downloading