Deserts in a Changing World: Ecological Responses and Feedbacks to Climate Change
"Desert. noun. Land that is uninhabited or not fit for crops. Synonyms: barren, desolation, no-man's-land, waste" - Merriam-Webster
In contrast to the desolate depiction that deserts often receive, deserts are both teeming with life and critical for sustaining global processes essential to life on Earth. Arid and semi-arid ecosystems ('drylands') cover some 40% of the Earth's land surface, supporting more than a third of the human population and the majority of the world's livestock. However, drylands - so critical to life on Earth - are also among the systems most vulnerable to global change. For example, increases in shrub cover are affecting ecological and biogeochemical processes in drylands globally. Similarly, climate change is predicted to be more extreme in drylands than many wetter systems. The biological consequences of climate change may also be severe, as small changes in climate may be enough to negatively affect organisms already frequently pushed toward their physiological limits in drylands. In this colloquium I will overview some recent research from my lab on dryland carbon cycling and responses to climate change in the southwestern United States, Australia, and southern Africa. Since dryland soils worldwide contain 40% as much carbon as the entire atmosphere, even small changes in dryland carbon storage have the potential to affect global carbon cycles, atmospheric carbon dioxide content, and climate.