Biological soil crusts, also known as cryptobiotic soil crusts, are widespread in the Nambé Badlands, especially on the west side of NM 503 in the Sombrillo Area of Critical Environmental Concern (ACEC). These soil crusts are alive. Cyanobacteria (blue-green algae), fungi, bryophytes, and lichens grow on top of the powdery desert soils in the area. Biological soil crusts stabilize the weak and fine desert soils in which they grow.
The globular raised black nodules are living biological soil crusts, photo taken in the Sombrillo ACEC.
Biological soil crusts are vital to the health of the Nambé Badlands by
- Increasing the stability of the highly erodible landscape in the Nambé Badlands
- Improving water infiltration into the soil needed for the trees and plants
- Increasing the fertility and essential nutrients of the soil
A foot trail or bike track across the cryptobiotic crust allows wind to blow the fine powdery soil as dust across the adjacent cryptobiotic crust, killing it. This widens the track, forever spreading the damage as the wind blows more and more dust, killing more and more cryptobiotic crust.
Recovery rates for lichen ground cover in desert landscapes of the southwestern US have been most recently estimated at a minimum of 45 years, while recovery of moss ground cover was estimated at 250 years. The recovery rate of biological soil crusts depends on many factors.
One bike track can take decades to hundreds of years to recover!
The cryptobiotic crust also stabilizes the weak and highly erodible soil against water runoff. When a bike track breaks the crust, it channels water, carving out deep trenches (sometimes a few feet deep!). The newly eroded grooves then channel more and more water, eroding the landscape in an irreversible cycle.
Mountain bike tracks across cryptobiotic crusts in the Sombrillo ACEC have evolved into deep and ugly scars.
All it takes is one biker to go off-trail into the cryptobiotic crust to start a decades-long erosional process damaging the land.
Do not bust the crust! Please stay on existing and authorized trails.