Valitdating methods for estimating carbon sequestration and potential of Vitellaria paradoxa c.f. Gaertn. in delivering ecosystem services from parkland systems in southern Mali, West African

Abstract

Vitellaria paradoxa is an indigenous tree species endemic to the African savannas. This species plays an important role in farmer’s mitigation and adaptation to climate change through its ecosystem services. Unfortunately, the species is declining in the Sahel including southern Mali because of its sensitiveness to recurrent drought due to climate change. Understanding the underlining processes of such decline and their consequences on the livelihoods of the rural farmers requires the development of appropriate methods and approaches. Therefore our study aimed at validating methods for estimating carbon sequestration and evaluating the potential of V. paradoxa in delivering ecosystem services for the well-being of the population in southern Mali. But before we attempted to elucidate farmers’ perception of climate change and their coping measures. Our findings revealed a range of coping measures used by farmers to adapt to climate change effects including the use of improved drought-tolerant crop varieties, diversification of crops, off-farm activities and seasonal migration. The contribution of V. paradoxa in annual gross income of rural households ranged from 4% in Koutiala (northern site) to 8% in Yanfolila (southern site). This seems to indicate an increase of the importance of this species in relation to increase rainfall and increase density of V. paradoxa going from the north to the south of Mali. Methods testing revealed that agent based could be used for V. paradoxa yield dynamics assessment in one hand and in another hand that fractal branch analysis (FBA) could be used for the above and belowground biomass and carbon estimation of this species. The aboveground carbon stock in Koutiala (2.16±0.44 Mg C ha-1) by shea trees was not significantly different from that of Yanfolila (3.21±0.60 Mg C ha-1). Similar trend was observed for the belowground carbon stocks between sites. This study indicated the risk of overestimating the biomass using generic model as all values of b were below 2.67. Furthermore, it clearly indicated that dendrochronology can be applied to study the impact of climate change on the growth of V. paradoxa.