The socio-ecology of the Caatinga: Understanding how natural resource use shapes an ecosystem

Abstract

The use of natural resources can be a main source of disturbance to natural ecosystems if human populations depend heavily on biomass to attend to their basic needs. However, our understanding of how natural resource use affects natural ecosystems is insufficient. The Caatinga is the most populated dry forest worldwide, and inhabitants depend largely on the exploitation of the natural ecosystem for several purposes such as fuelwood and raising livestock. These constitute 'chronic anthropogenic disturbances' (CAD), the impacts of which, in the long run, may compete with habitat loss and impacts on ecosystem health. In this chapter I present a theoretical framework for the assessment of the impacts of three main sources of CAD on the Caatinga. I discuss how (1) firewood harvesting, (2) raising of free ranging goats, and (3) biological invasion are all linked to changes observed in the Caatinga biota. These sources of CAD are all linked to the socio-economic condition of human populations inhabiting the Caatinga and can be understood and, to some extent, quantified through socio-economic assessments. Finally, I propose a theoretical framework on how the original features of the Caatinga ecosystem may change as a function of the intensity of CAD, leading to two alternative states of both conserved and altered similarity to the original ecosystem. Understanding natural resource use by human populations is crucial to being able to assess the threats to biodiversity and ecosystem functions properly as well as to design conservation strategies to avoid both ecosystem degradation and depletion of human livelihoods.