Pentadesma butyracea is a multi-purpose tree that provides non timber forest products. Kernels from fruits are transformed into butter. There is a consistent gap in scientific knowledge on the species ecology and its socio-economical role in rural area. This study aims : (i) to examine the diametric structure and the fruit harvesting impact on the native recruitment of populations of P. butyracea ; (ii) to access the financial profitability in commercializing the non timber forest products of P. butyracea .

The survey was conducted in Pénessoulou District, in the Middle - Western of Benin (9-9°15 Northern latitudes; 1°30-2°Eastern longitudes) in the Sudano-Guinean transition climate zone.

Twenty plots of 50 m x 20 m were established in 13 riparian forest sites hosting P. butyracea. The choice of the plots sizes used the target species nature and the riparian forests lie. Then plots were sampled in a high-intensity fruit harvesting site and 10 other in a low-intensity fruit harvesting site. P. butyracea population diameter class distributions were performed by measuring the dbh of individuals (dbh > 10 cm) at 1.30 m from soil. Five sub-plots of 5 m x 5 m were laid out per plot: a subplot per a plot corner and in the centre. P. butyracea recruitments from root suckers or seedlings were assessed per subplot by counting individuals with diameter at breast height (dbh) < 10 cm; their origin was also determined. Forest relevés were also realized per plot. Variance analysis and Student - Newman - Keuls test were used to compare seedlings individuals’ densities, according to fruit harvesting pressure (high versus low). In the hierarchical mixed model used for ANOVA, Intensity of fruit harvesting (high versus low) represents the fixed factor while the plots, the random factor. Statistical analyses were performed using SAS software, version 9.1.  and multivariate analysis (classification and ordination).

Financial profitability analysis of P. butyracea fruit harvesting and kernel transformation activities were based on quantitative and qualitative data collection. These data are related to activities, tools, duration, purchase prices of kernels and butter, quantities of kernels harvested, processed into butter and sold or bought. Gross margin and profitability ratios per activity were estimated as follow:

Gross margin: GM = R - C (1), With GM = gross margin, R = returns, and C = fixed costs.

Profitability ratio: PR = GM/C (2).

Surveys on the commercial channels of P. butyracea kernels and butter were performed and the margin analyses used qualitative and quantitative data such as roles fulfilled by different stakeholders of commercial channels; different expenses made by each stakeholder during transactions; purchase and transfer prices of kernels and butter on local markets during the two last years; quantities of kernel and butter harvested, transformed, sold or bought.

A total of 60 women involving in P. butyracea kernels and butter production as well as their commercialization were randomly selected with 22 fruit harvesters, 15 kernel processors (butter), 11 kernel traders and 12 butter traders. Investigation techniques used involved structured, semi-structured and non-structured interviews and participative observations. Commercial margins of P. butyracea kernels and butter were assessed using expression adapted from Shepherd (1994):

CM = (SP-PP)/PC (3)  

with CM = commercial margin of each stakeholder, PP= purchase price of the product, SP = selling price of the product and PC = price paid by the final consumer.

Arithmetic average and margins values were used to assess profits and commercial margins.

• Diameter structure varies from one site to another. In the low fruit harvesting sites, populations showed an exponentially decreasing reversed J-shaped distribution. On the other hand, high fruit harvesting sites populations showed an erratic structure; there are no individuals with small diameters.

• The Number of plants regenerated from seeds and total regeneration densities between the two types of fruit harvesting intensity sites: low and high (respectively F = 17.16; p = 0.0006 and F = 12.20; p = 0.0026). On the other hand, the number of regenerated plants by suckers does not differ significantly between the   zones of high and low -intensity fruits harvesting (F = 0.79; p = 0.3861).  

• P. butyracea belonged to Berlinia grandiflora community and Lannea sp. community in wet sites.

• Harvesting and kernel processing activities are financially profitable with profitability ratio of 208 % for fruit harvesting versus 12.17 % for kernel processing.

• P. butyracea kernels trade used 4 channels: (i) collector – transformer channel;  (ii)  collector – village wholesaler – transformer channel; (iii) collector – district collector – wholesale collector – tropical product society exporter channel;  (iv) collector – village wholesaler – district collector – wholesale collector – tropical product society exporter channel.

• The butter trade showed three commercial channels: (i) transformer – consumer channel;  (ii) transformer – village retailer – village consumer channel; (iii) transformer – village retailer – village wholesale collector – urban centre retailer – urban centre consumer channel.

• P. butyracea’s fruits collectors and kernels transformers receive 49 to 80 % of the consumer price following the product and commercial channel.

P. butyracea fruit harvesting could have a negative impact on the future structure of the species’ populations. There is a significant difference between seedlings density from low-intensity to high-intensity fruit harvesting areas. P. butyracea fruit collection and kernel transformation is financially profitable with a higher ratio for fruit harvesting. Women are the main stakeholders of P. butyracea kernel and butter marketing channels. Commercial margin analysis showed that the P. butyracea products trade is actually viable.

Keywords : Pentadesma butyracea, density, harvesting impact, profitability, trade channel, Benin.