Stay off the Cryptobiotic Crust!
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[1]Belnap, J., 1993, Recovery rates of cryptobiotic crusts: Inoculant use and assessment methods: Great Basin Naturalist, v. 53, p. 89-95. 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.
Careless mountain bike riding off a well-established legacy trail, BLM Trail Segment 2031. (Photo was taken October 4, 2020 at 10:44 AM)
This photograph shows the erosional damage that one bike track can do in a short time frame. This is a recent illegal trail that was constructed using picks and shovels through sensitive formations (paleontology resources) in the Sombrillo ACEC. BLM trail segment #2P.
A recent illegal mountain bike trail, BLM Trail Segment 16p (aka “Richard’s Avenue”), constructed across a sloped field of cryptobiotic crust, is shown here. Water has already started to channel down this sloped trail and erode the surrounding cryptobiotic soil. (This photo was taken on March 20, 2021, just after the illegal trail was built (between March 2 – 19, 2020.)
Short-cutting across cryptobiotic soil crusts on a recent illegal trail, BLM trail segment #19P. Not only are rogue mountain bike groups and individuals constructing illegal trails in the Sombrillo ACEC, but they also cannot even stay on the trail!
The deep channel carved into the soft soil that underlies the cryptobiotic soil crust is shown here. This photo was taken on March 20, 2021, within two weeks of the trail construction. This shows how quickly the highly erodible soil can be damaged. Wind now blows the dust from the trail onto the cryptobiotic soil adjacent to the illegal trail and kills it. Water has already run down this trail channel and eroded it even deeper. BLM trail segment #16P, aka “Richards Avenue“.
This seldomly used trail, relative to the increased use observed in other parts of the Sombrillo ACEC, goes through a biological soil crust field.
References
| ↑1 | Belnap, J., 1993, Recovery rates of cryptobiotic crusts: Inoculant use and assessment methods: Great Basin Naturalist, v. 53, p. 89-95 |
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