MSc
Steve Perrin Nandjou Mongou
MRes, Faculty of Agronomy and Agricultural Sciences, Department of Forestry, University of Dschang, Cameroon
Project summary
Steve holds a Master’s degree (Master 2) in Agricultural Engineering, specialising in crop production, from the Faculty of Agronomy and Agricultural Sciences (FASA) at the University of Dschang, Cameroon. He has successfully completed his MRes in the FASA, Department of Forestry, at the University of Dschang, Cameroon. Steve’s project is entitled Vegetation structure and productivity in coffee agroforestry systems in the production basins of the littoral and Western regions of Cameroon.
The forests of the Congo Basin, the world’s second-largest ecological lung after the Amazon (Sist, 2024), are experiencing increasing anthropogenic pressure: nearly 3.9 million hectares were lost in Central Africa between 2010 and 2020 (Vancutsem et al., 2021), mainly due to the conversion of forests into agricultural land (Momo Solefack et al., 2018; Tsewoue et al., 2020). Yet forests play an essential role in biodiversity conservation, carbon storage, climate regulation, and the provision of products and services to local populations (Batsi et al., 2021), while population growth and agricultural expansion continue to heighten the risks of deforestation (UN, 2017).
In this context, agroforestry represents a sustainable alternative that reconciles agricultural production with biodiversity conservation, soil fertility, and carbon sequestration (Temgoua et al., 2018). Coffee-based agroforestry systems, in particular, contribute to crop resilience and the maintenance of ecosystem services (Niether et al., 2020). In Cameroon, the Littoral and Western regions are major coffee-producing areas. However, unlike cocoa agroforestry systems, which have been extensively studied (Mapongmetsem et al., 2015; Djeuni et al., 2025), coffee agroforestry systems remain poorly documented (Fouellefack, 2015; Temgoua et al., 2020), despite their importance within Cameroon’s agricultural landscape (Ngomeni et al., 2021).
Research has evolved from merely describing these systems to assessing their productivity and analyzing interactions among associated species (Beer et al., 2003). Coffee agroforestry systems can maintain levels of biodiversity comparable to those found in secondary forests (Saj et al., 2017) and represent a relevant option for climate-smart agriculture in these coffee-growing regions (Fogang et al., 2024).
More specifically, this study seeks to answer the following primary research question:
How does vegetation structure influence the productivity of coffee-based agroforestry systems in the main coffee-producing areas of the Littoral and Western regions of Cameroon?
The following secondary research questions arise from this main question:
- What are the floristic composition and stand structure of coffee-based agroforestry systems?
- What are the physicochemical characteristics of soils in coffee-based agroforestry systems?
- Which management practices, in relation to structural characteristics, influence the production of marketable coffee in agroforestry systems?
- What carbon stocks and ecological value can be generated by coffee-based agroforestry systems?
From a methodological perspective, the study combined:
- Socioeconomic surveys conducted with 100 producers;
- Floristic and dendrometric inventories carried out in 2,400 m² rectangular plots containing 800 m² nested subplots, stratified into three age classes (young < 20 years, mature 21-40 years, and old ≥ 41 years);
- Soil sampling at two depths (0-15 cm and 15-30 cm) for the analysis of pH, nitrogen, phosphorus, organic carbon, and soil texture.
Woody biomass was converted into carbon stocks using the allometric equations developed by Chave et al. (2005).
Expected results
The study reveals significantly higher floristic richness in the Noun Division (43 species, 32 genera, 26 families, dominated by the Fabaceae) than in the Moungo Division (20 species, 17 genera, 15 families, dominated by the Arecaceae and fruit tree species). This diversity declines with the age of the agroforestry systems in both sites, reflecting structural simplification associated with intensified management practices. Nevertheless, the inverted J-shaped diameter distributions indicate a strong potential for natural regeneration.
From a soil perspective, the soils in both divisions are moderately acidic (pH 5.5-5.9), low in available phosphorus, and generally exhibit a carbon-to-nitrogen (C/N) ratio greater than 15. Organic matter decreases with system age in Noun but increases slightly in Moungo. This trend is explained by the predominance of fruit trees (avocado, African pear, and oil palm) rather than by shade density.
Weeding is the dominant management practice. However, the main constraints differ between the two sites, with pest pressure affecting 88% of farms in Moungo and water stress affecting 53% of farms in Noun. Coffee yields (400-1,200 kg/ha) are generally higher in Noun, confirming the relationship between structural complexity and productivity.
Finally, carbon stocks increase significantly with the age of the agroforestry systems (AFS), rising from 19.27 to 83.68 t C/ha. This increase is driven primarily by trees with diameters greater than or equal to 30 cm and is more pronounced in Noun. These findings confirm all four study hypotheses (H1-H4) and highlight the multifunctional role of mature coffee-based agroforestry systems, which simultaneously generate income and provide climate-regulating ecosystem services.
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