Get to Know Desert Soils

When you think about a desert landscape, what do you picture? A cactus, perhaps?  Small bushes or tumbleweed? Plants are of course an important part of a desert ecosystem, but when you look at a photo of the desert, you see that it is dominated by one important feature: soil!

Salt River Recreation Area, Mesa AZ, Sonoran Desert

Soil in deserts, such as the Sonoran Desert where I live and work, tends to be very sandy with only small amounts of scattered vegetation. While the soil may look barren, it is not dead! Look carefully at this close-up photo of the soil below. There is a bursage, some grass, even a mouse! There are also clumps of bacteria, lichen, and moss, which are the dark brown "crusts" you see around the plant.

There is a lot of life in this photo, if you look closely!

If you look even closer, with the help of a microscope, you would be able to see that there are a lot of even smaller organisms living in the soil that do many important things to sustain the ecosystem.

http://www.teara.govt.nz/en/photograph/12725/soil-mites

All sorts of organisms live in the soil all over the world. When you walk on the ground, you're walking on thousands and thousands of critters that you can't even see, with every step! Most of the organisms in soils are bacteria and fungi. The fungi living in the soil aren't mushrooms, like you're used to seeing. They're microscopic fungi. Bacteria and fungi live in soils all over the world in every biome, and deserts are no exception! There are also things living in the soil that eat the bacteria and fungi. In many places, like deciduous forests in the U.S., there are tons of different types of organisms living in the soil that eat microscopic bacteria and fungi. On Antarctica, there aren't so many different types, because it's a much harder environment to live in. However, there are some here, but they're all microscopic! There's organisms like protozoa, tardigrades, collembola, nematodes, and many more! You can see some of the diversity of soil organisms in this photo.

These organisms live, eat, breath, and die in the soil, and the result is that they recycle important nutrients through the soil to support plant life. Those plants support herbivores, like the pocket mouse you see here. Soil is the important resource that supports this entire food web of plants and animals!



Want to learn more? You can watch a video that explains the importance of our research in desert soils by clicking here.