Dendrochronological Potential and Impact of Climate Factors on Radial Growth of Two Species in the Sahelian Zone: Boscia senegalensis(Pers.) Lam. ex Poir and Sclerocarya birrea(A. Rich) Hoscht (Ferlo Nord/Senegal)

摘要

The objective of this study is to analyze the dendrochronological potential of two Sahelian species (B. senegalensis and S. birrea) and to evaluate the relationships between their growth rings and the climate. The study was conducted in 2016 in the Ferlo area of Senegal. The biological material consists of wood slices, taken from the trunks of these adult woody species at 0.30 m and 1.30 m from the ground after they have been felled. The technique used to examine the slices consists in identifying their rings, establishing their structures, inter-dating them and studying the relationship between the identified rings and climatic factors. The results showed that the species had thin, clear, highly visible and sharp rings. The limit of growth is marked by a line of parenchyma. Intradatation series carried out on the chronologies made it possible to estimate the ages of the individuals, which vary from 10 to 38 years for style="font-family:Verdana;">B. senegalensis style="font-family:Verdana;"> and from 29 to 50 years for style="font-family:Verdana;">S. birrea style="font-family:Verdana;">. Their average growth style="font-family:Verdana;">rates are estimated at 0.906 mm/year and 0.89 mm/year respectively. The style="font-family:Verdana;">chronological sequences are 29 years (1987-2016) for style="font-family:Verdana;">B. senegalensis style="font-family:Verdana;"> and 38 years (1964-2012) for style="font-family:Verdana;">S. birrea style="font-family:Verdana;">. The results revealed that there is no significant correlation between the growth chronologies of style="font-family:Verdana;">B. senegalensis style="font-family:Verdana;"> and the style="font-family:Verdana;">climatic regressors (temperature and precipitation). In contrast, the ring- style="font-family:Verdana;">climate relationship shows that in style="font-family:Verdana;">S. birrea style="font-family:Verdana;"> winter precipitation positively influences ring growth while temperature has no effect on ring growth in this species. This study provides a better understanding of the response of forest ecosystems to possible climate change, particularly in the current context of sustainable forest management.