Socioeconomic and Environmental Changes in Global Drylands

Abstract

AbstractDrylands are a pivotal component of Earth’s biosphere and provide essential ecosystem services to mankind. Over the past several decades, with rapid population growth, global drylands have been experiencing quick socioeconomic transitioning. Such socioeconomic changes, together with fast climate change, have dramatically altered dryland ecosystem functioning and the quality and quantity of ecosystem services they provide. In fact, complex interactions among climate, vegetation, and humans, involving multiple biophysical, biogeochemical, societal, and economic factors, have all played important roles in shaping the changes in global dryland environment. A comprehensive review of socioeconomic and environmental changes of global drylands and their underlying mechanisms would provide crucial knowledge informing ecosystem management and socio-ecological capacity buildup for a more sustainable future of global drylands. In this chapter, we would begin with summarizing the characteristics of socioeconomic changes in drylands. We then presented and discussed past and future projected changes in dryland ecosystem structure and functioning (e.g., vegetation growth, land cover changes, carbon sink, water-use efficiency, resistance/resilience to disturbances) and hydrological cycles (e.g., soil moisture, runoff, and groundwater storage). We also discussed new understandings of mechanisms underlying dryland eco-hydrological changes.