Crunchy SoilIf you ever go off-trail in the iconic deserts of the American Southwest, you might noti
Crunchy SoilIf you ever go off-trail in the iconic deserts of the American Southwest, you might notice a distinct crunch when you step. It’s a very significant crunch—it’s the sound of a very important soil called cryptobiotic soil or biological soil crust. Like most soil, cryptobiotic soil has a few components but one of its most important is cyanobacteria. Cyanobacteria is a binding agent when it gets wet. Tiny little filaments from the bacteria extend and move around in the soil, locking soil and other particles in place. This is a huge help against soil erosion, since particles that otherwise would be washed away quite easily are now safely stuck in cyanobacteria’s sticky network. Cyanobacteria are also nitrogen “fixers”. Nitrogen is incredibly important for plant growth, but as it is in the atmosphere, it’s completely useless. Nitrogen must be converted from N2 to NH4+ or NO2. Cyanobacteria in soil crusts do a great job at that and provide needed nitrogen in a land of limited resources.Cryptobiotic soil is a very fragile resource, so if you ever hear that crunch or notice a black crusty top layer to the soil, it’s time to get back on the trail. It can take up to 7 years for a biological soil crust to regenerate after its been damaged. These soil crusts have suffered a lot at the hands of rogue hikers, mountain bikers, and ATV’s. Loss of soil crust can lead to increasing rates of soil erosion, which is devastating for desert ecosystems. -CMPhoto credit: Canyonlands National Park http://bit.ly/1LK451iFor more information:http://bit.ly/1HN3xH4http://on.doi.gov/1POTIj5To read more about soils: http://bit.ly/1HN3xH4 -- source link
#geology#erosion#weathering#cryptobiotic#cyanobacteria#nitrogen#filament#chemistry#biology