Biophysical Characterisation of Baobab Parks in Middle and Upper Casamance in Southern Senegal

Abstract

In the middle and upper Casamance, the products of the baobab tree (Adansonia digitata L.) make an important contribution to the lives of the population. However, information on the status of baobab populations in this area is insufficient. The aim of this study is to characterise the baobab parks in this area from a biophysical point of view. To do this, the sample involved 756 baobab trees, 89 of which were in hut parks, 223 in villages and 444 in the bush. The parameters assessed on each baobab tree were circumference at 1.3m, total height, crown diameter, number of primary branches, distance between individuals, level of fruiting and signs of anthropisation. The data were subjected to an analysis of variance with the ANOVA test followed by the Student Newman Keuls test at the 05% threshold. The results showed a significant difference (Pvalue <0.05) between parks for each parameter except circumference at 1.3m. The village parks had the highest values for circumference at 1.3m (5.27±2.12m), for crown diameter (14.06±6.62m) and for distance between baobabs (19.12±8m). On the other hand, the tallest baobabs (37.79±8.93m) with the highest number of primary branches (22±14) are observed in the bush parks. According to the structural analysis, the majority of the parks (<50%) have large baobabs. The hut and village parks are dominated by the height and diameter classes of [25-35] m and [5-10] m respectively. On the other hand, in the bush parks, the most represented baobabs are found in the height <35m and diameter [1-5] m classes. Furthermore, the results on fruiting showed that bush parks have more baobabs with a high level of fruiting. Also, concerning anthropisation, high rates (more than 52% of baobabs) were noted for each type of park. These results show an ageing baobab population threatened by strong anthropic pressure. Thus, efforts should be made to ensure the survival of these baobab populations, which are essential to the life of local populations, through better management.