Sustainability of the Dry Forest in Androy: A Viability Analysis

•We model the traditional economic system of Tandroy people in the South of Madagascar.•With the help of viability theory we are able to determine that their system is unsustainable.•Sustainability requires changes in deforestation, afforestation, birth rates and consumption.•We compute how much money will cost to keep both current consumption and current forest area constant.

We investigate the dynamic effect that the Tandroy's unsustainable practices have on the forest. The Tandroy people live in Androy, a region located in the southern part of Madagascar. They are mainly an agricultural and cattle herding society whose subsistence relies on the slash-and-burn farming agriculture (hatsake) and the burning of cacti which are given as fodder to the livestock (ororaketa). These activities generate ecological pressure on the surrounding dry forest and socioeconomic risks related to the lack of sustainability of these practices in the long run. In this paper we address the notion of sustainability and confront it with Tandroy's current productive and economic system. By means of the viability theory, we characterize the actions and scenarios that are compatible with a sustainable use of the forest in the region.