Overview SOIL 1
Apparently frost -heaving has raised very weak physical (WP)
crust-mounds.
Closeup of a crust mound:
The surface has been softened and the top centimeter has filled in with
fine sediments. This top layer actually
has more structure than the frost-heaved material below it, which readily
crumbles into its constituent soil particles.
Note the plant root, at top center of the photo, growing in the fine
sediment layer.
Where litter is present, but too discontinuous to form duff,
the action of frost heaving rapidly incorporates pine and juniper litter into
the mineral horizon.
Overview SOIL 2
Some areas have much more biological crust than others. In these photos, the blue grama grass Bouteloua gracilis (BOGR) is more
abundant with denser cryptobiotic crust.
The darkened biological soil crust (BSC) consists of free-living
blue-green algae such as Nostoc.
Compact SP (strong physical) crust with roots and moisture evident
underneath. These cracked peds come up
in 5-8 inch radius plates. Note how
different this crust is from the previous “frost-heaved” crust. This crust has significant structure to it
and doesn’t immediately crumble into constituent particles.
1 comment:
What are the differences in site locations/environmental conditions between the area where the weak physical crust resides and that where the strong physical crust resides??
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