Sustainability of small-scale social-ecological systems in arid environments: trade-off and synergies of global and regional changes

The sustainability of small-scale social-ecological systems (SESs) in drylands is challenged by external socio-economic and environmental drivers of change that interact both with one another and with endogenous drivers unexpectedly and in complex ways. Understanding the way large-scale changes interact with endogenous drivers and affect the sustainability of drylands is, thus, crucial for policy insights that aim to foster the stewardship of drylands in desirable states. By the system dynamics approach, we developed a dynamic simulation model to: (1) quantitatively analyse the relative weight of each driver type on the local dynamics of the SES of the oasis of Comondu (Baja California Sur, Mexico), which has witnessed sharp depopulation in recent decades; (2) identify and quantify cross-scale interactions; (3) discuss the local sustainability implications. Based on local knowledge, our model successfully simulated the SES' historical behaviour. Our simulation showed that external drivers linked to global drivers, especially climatic drivers, have markedly influenced the local dynamics. However, endogenous factors (e.g. local economy, employment) have proven relevant in shaping this SES' sustainability outcomes. The reinforcing relationship between the effects of the variability of rainfall and the volatility of market prices warns about the system's vulnerability to a double exposure: climate change and globalisation. Our study demonstrates the suitability of dynamic simulation models to address key issues for sustainability science, like studying the long-term dynamics of SESs, interactions between regions, and place-based and problem-oriented approaches to solve real-world problems.