EFFECT OF LAND MANAGEMENT ON THE DYNAMICS OF NATURAL REGENERATION OF AGROFORESTRY PARKLAND FOREST TREE SPECIES. CASE STUDY OF VITELLARIA PARADOXA IN SOUTHERN MALI (WEST AFRICA)

The dynamics of the natural regeneration of Vitellaria paradoxa (karité or shea tree) was studied in southern Mali with the aim of assessing the effect of human practices of land use (forest, fallow). Different categories of regeneration were monitored during three years in forest and fallow stands. The spatial distribution, the density and the growth of the regeneration were studied and stands were compared using SAS’s GLM procedure. Time effect and the different interactions were tested using SAS’s repeated measures method. The regeneration was differently distributed in the stands. In the fallow stand it occurred across the whole area while in the forest stand it appeared as Patches Under Karité trees (PUK), Patches Under Other tree Species (PUOS) and Patches Out of any Cover (POC). The density of the regeneration was higher in the fallow stand, but the effect of stand was not significant for height growth. In the forest stand, patch effect on measured variables was weak. A significant time effect on height growth was observed and the time*patch interaction was significant also. Variations of density and growth were observed according to year, suggesting high sensitivity of shea tree natural regeneration to varying environmental conditions

Parkia biglobosa (Nere)-A threatened useful tree species: Directory of sanitary constraints according to north-south climatic gradient in Mali

Parkia biglobosa, a multi-purposes species offers food, medicine and income to rural populations. This species is facing several constraints mainly aged populations, weak natural regeneration, and reduction of tree densities. A study, was undertaken in three sites from three agro-climatic zones according to the north-south climatic gradient in southern Mali, to assess dendrometric characteristics of Parkia biglobosa trees. Permanent plots of 0.25 ha each were installed in fields and fallows with three replications in each stand within each site. Adult trees in the plots were monitored, measured and also assessed for sanitary constraints. Several sanitary constraints were encountered and classified into six categories (from attacks on trunks and gross branches to damages on fruits and general attacks, infestations and damages due to wood-boring insects, human beings and other abiotic factors). Damages like those with symptoms of dieback or staghead disease pose a serious threat for production, productivity and survival of the species. Concrete actions are necessary like sanitary diagnostic at the level of the distribution area of the species in Mali, followed by identifying real cause of damages and seeking for appropriate solutions, sensitizing and training farmers, implementing a national program of regeneration of the species by planting and/or by promoting Assisted Natural Regeneration (ANR) approach

Impact of land use and land use history on fruits production of Vitellaria paradoxa (Shea tree) according to agroclimatic zones in Mali (West Africa)

To understand how various factors influence phenological patterns like fruit production and the extent of phenological variability as survival strategy in different environments, fruit production of shea trees was studied in different agroclimatic zones (North Sudanian, South Sudanian and North Guinean) in Mali. Three sites were selected for this study and in each site; two stands (field and fallow) were concerned. For each stand, three “land use history or land management" i.e. new fields/fallows (1-5 years), medium (6-10 years) and old (10 years) were considered and permanent plots of 0.25 ha were established. 60 adult shea trees (DBH) ? 10 cm) were selected by site and monitored for fruit production assessment. The nested analysis of variance on the yield showed a significant site effect and significant effect of land use history within stand. However, stand effect within site was not significant. Factors like site and land management (land use history) appear to be determinant for fruit production of V. paradoxa. The site of Mperesso in the South Sudanian zone showed the highest fruit mean yield (11 kg/tree), significantly higher than the fruit mean yield observed at Daelan (7 kg/tree) in the North Sudanian zone and that observed at Nafégué (6 kg/tree) in the North Guinean zone. For field stand, old fields showed highest mean yield in all sites. For fallow stand, old fallows showed the lowest mean yield in most of cases. Different pattern was observed between field and fallow stands regarding the effect of land management. More fields are aged, more they influence positively fruit production whereas more fallows are aged, and more they influence negatively fruit production. This study highlighted the importance of land management practices and therefore, any domestication program to be successful should consider the potential effect of management practices

Variation of Vitellaria paradoxa phenophases along the north-south gradient in Mali

We monitored flowering, fruiting and leafing of Vitellaria paradoxa (shea tree) along the north–south gradient in Mali (West Africa), using three study sites for a period of three years. In each site, adult shea trees were marked and monitored in permanent plots of both field and fallow stands. The chronology of phenophases and their mean length as well as flowering and fruiting were assessed. Our data revealed significant variation according to site and stand. The onset of events starts earlier in the south than in the centre or north, but the period covered by events was almost the same for all sites (3 to 6 months for flowering; 5 to 6 months for fruiting; and 2 to 4 months before full leafing).Flowering and fruiting were more regular in the south, but often as high in the north, with an almost similar trend in both fields and fallows. In the centre, flowering was also high in fields as well as in fallows, while the fruiting was medium to high. We also observed variations in the mean length of phenological events in study sites and stands. Sites in the south showed the highest average length of flowering and leafing (76 days and 44 days, respectively), while the central site showed the greatest length of mean fruiting (110 days).  We observed a significant site*stand interaction and noticeable variation over the years. Our study indicates that phenological events of shea tree could be influenced by several interacting biotic and abiotic factors. A future research challenge in shea phenology would be to discriminate these factors and thus help sustainable management of shea tree parklands

Natural Regeneration of Parkia biglobosa (Néré): Status and variation along the South-North climatic gradient in Mali

Parkia biglobosa offers food, medicine and income to rural populations. A study, was undertaken in three agro-climatic zones in southern Mali, to characterise P. biglobosa populations. Plots of 0.25 ha each were established in fields and fallows and adult trees in the plots were monitored. Natural regeneration was monitored in five subplots of 12.5 m x 12.5 m = 156.25 m2 each within each plot and data were collected from 2019 to 2021. Natural regeneration of P. biglobosa was found to be very weak in all sites. The mean density of seedlings varied from 11 to 24 seedlings ha-1 with a decreasing trend from 2019 to 2021. In Zanzoni, where the weakest regeneration was observed, the density varied from 0 to 8 seedlings ha-1. The highest density of seedlings was observed in Somasso in 2019 (42 seedlings ha-1) and 2020 (30 seedlings ha-1). In 2021, the highest density was observed in Diou (25 seedlings ha-1). The weakness of natural regeneration is very alarming for this tree species facing several other threats (ageing and decreasing adult tree populations, sanitary constraints, several pressures, etc.). It is therefore very important and imperative to investigate ways for regenerating the species for its sustainability and for maintaining the parklands biodiversity. Artificial regeneration (planting), could be the one and ultimate way to ensure the sustainability of P. biglobosa

Afforestation using local forest tree species on hydromorphic soil. Results of a forestry experiment in Southern Mali

Un essai, installé en 1989 au sud du Mali, comprend l'étude de l'effet de deux préparations manuelles du sol sur le comportement de six espèces. Anogeissus leiocarpus, Prosopis africana et Khaya senegalensis se comportent bien sur des sols hydromorphes ; Parkia biglobosa, malgré une bonne croissance en hauteur, et Tamarindus indica, en dépit de bons taux de survie, ont des problèmes d'adaptation à ces types de sols ; Faidherbia albida n'est adapté ni aux sols argileux, ni aux terres limoneuses-argileuses de cette station. Ces espèces peuvent être plantées sur des petits potets (trous cubiques de 30 cm d'arête). Khaya senegalensis mérite d'être planté avec de larges espacements alors qu'il est recommandé, pour Tamarindus indica, de recourir à des plantations à densité initiale élevée dans un objectif de bois de service

Impact of land use and land use history on fruits production of Vitellaria paradoxa (Shea tree) according to agroclimatic zones in Mali (West Africa)

To understand how various factors influence phenological patterns like fruit production and the extent of phenological variability as survival strategy in different environments, fruit production of shea trees was studied in different agroclimatic zones (North Sudanian, South Sudanian and North Guinean) in Mali. Three sites were selected for this study and in each site; two stands (field and fallow) were concerned. For each stand, three “land use history or land management" i.e. new fields/fallows (1-5 years), medium (6-10 years) and old (10 years) were considered and permanent plots of 0.25 ha were established. 60 adult shea trees (DBH) ? 10 cm) were selected by site and monitored for fruit production assessment. The nested analysis of variance on the yield showed a significant site effect and significant effect of land use history within stand. However, stand effect within site was not significant. Factors like site and land management (land use history) appear to be determinant for fruit production of V. paradoxa. The site of Mperesso in the South Sudanian zone showed the highest fruit mean yield (11 kg/tree), significantly higher than the fruit mean yield observed at Daelan (7 kg/tree) in the North Sudanian zone and that observed at Nafégué (6 kg/tree) in the North Guinean zone. For field stand, old fields showed highest mean yield in all sites. For fallow stand, old fallows showed the lowest mean yield in most of cases. Different pattern was observed between field and fallow stands regarding the effect of land management. More fields are aged, more they influence positively fruit production whereas more fallows are aged, and more they influence negatively fruit production. This study highlighted the importance of land management practices and therefore, any domestication program to be successful should consider the potential effect of management practices

A SHEA BUTTER RICH IN TOCOPHEROLS (VITAMIN E) AT THE DOGON PLATEAU AND SENO BANKASS IN MALI (WEST AFRICA)

Vitellaria paradoxa, a forest tree species plays an important role for rural populations in Mali. The kernel is rich in fat, fatty acids and tocopherols and the butter extrated from the kernel is used in many African kitchens, in pharmacology, cosmetics, local traditional medicine and as Chocolate Butter Equivalent (CBE) in chocolate industry. A consortium funded by the Europena Union has worked on several aspects of shea tree including chemical characterisation of shea butter. In Mali, one of the project partners, five sites were selected, fruits were collected from selected shea trees and sent to Montpellier for chemical analyses assessing among other variables the tocopherol content of the shea butter using liquid chromatography (HPLC). Results of this study shown that shea butter from the Dogon Plateau and the Seno Bankass is richer in tocopherols (Vitamin E) compared to other study sites. Sites were found significantly different for tocopherols content all together as well as for each type of tocopherol. The richness of shea butter from the Dogon Plateau and the Seno Bankass in tocopherols confers to it an important nutritional value for the good healf of rural populations of this zone, shea butter being the main source of fat for cooking in this area