Download Biological Soil Crusts:

Biological Soil Crusts:
Keystone of the Colorado Plateau
Keystone Species:
• Cyanobacterium: Microcoleus vaginatus
Figure 1. Filaments of Microcoleus
vaginatus (x 3000), the dominant
organism in the crust. Individual cells
abut each other to form the filaments.
from: http://geochange.er.usgs.gov/sw/impacts/biology/crypto/
Microcoleus
Figure 3. Microcoleus filaments
(lower left) emerging from
mucilagenous sheath (upper
right). Scale bar is 10
micrometers.
How is this a keystone species??
Figure 4. Crust in sandy soils. The visible fibers
are Microcoleus vaginatus. Note how
Microcoleus connects the otherwise loose sand
grains together, thus preventing wind and water
erosion. Microcoleus is important in enhancing
water and nutrient relations within the soil, as
well. Scale bar is 100 micrometers.
Cryptobiotic Soil Crusts
Open spaces covered by biological soil
crusts, a highly specialized community
of cyanobacteria, mosses, and lichens.
Cryptobiotic Soil Crusts
• Protection for plant seedlings
Cryptobiotic Soil Crusts
• Protection from erosion
Cryptobiotic Soil Crusts
• Easily destroyed by trampling, off-road
vehicles, etc.
ORVs in the Indian Creek area
travel off-route at nearly every
opportunity they have. Here,
illegal cross-country riding has
crushed cryptobiotic soils,
causing damage that could last
50 to 300 years. Indian Creek
proposed wilderness area. San
Juan County, UT.
redrockheritage.org/orv_gallery_2/