The map looks off. No way the American Southwest has 3 meters per cm cubed of fungal density in such an arid region. Plenty of desert.
The underground in desert regions can be much more humid and hospitable than the surface.
Well South Sudan as highlighted has 8, and thats basically a desert. Tibetan plateau is high altitude frozen desert with permafrost in many parts, and its 11.4.
Maybe there is more complexity than meets the first glance.
Fungi survive in deserts: https://insideclimatenews.org/news/22062025/sonoran-desert-s...