Beauty Can Be Just Skin-Deep: the Essential Role of Surficial Microbes in Current and Future Desert Ecosystem Function
In dryland regions, where plants are sparse, soil surface communities (including photosynthetic cyanobacteria, lichens and mosses, as well as fungi, heterotrophic bacteria, and soil microfauna) are often the dominant life form. These communities control many ecosystem processes in desert settings. They often determine local hydrology by roughening soil surface roughness and creating soil aggregates. They fix and contribute carbon and nitrogen to soils, and secrete compound to make phosphorus bio-available, a central role in deserts, where soils are often relatively infertile. They are critical in stabilizing soils, which helps maintain soil fertility, as well as reducing dust production and sediments entering streams. Unfortunately, biocrusts are highly vulnerable to soil surface disturbance and changing climate regimes, which will alter their role in the function of desert ecosystems. We will explore how changes to these communities can reverberate throughout trophic levels, as well how these changes can impact regional scale cycles.