WMOD00290 ‎(2)‎

• Project Name: The Medicine Bow Ecology Project
• Title: The Potential Sensitivity of Various Ecosystem Components to Winter Precipitation Management in the Medicine Bow Mountains, Wyoming
• Prepared For: Bureau of Reclaimation
• Date: 2/28/1975
• State: WY
• Weather Modification - Doc Type: Report

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the alpine area. Nimlos and Patt(e (196~) suggest that alpine soils
are those with a mean annual temperature less than 1.60C and a mean
SUl1lller soil temperature less than 4.40C.
Chemical, mineralogical, and morphological data all indicate that
the development of alpine soils is limited. Slow development of
alpine soils and cold temperatures also affect the numbers of soil
microorganisms. RaIl (1965) isolated 32 species of soil fungi on
Libby Flats in the Medicine Bow Mountains. It was interestrng to
note that neither the number of species nor total number of organisms
decreased with increasing depth of sampling. RaIl's data suggest
that soi 1 fungal populations in cold areas are much 'lower than in
temperate and tropical areas.
Johnson and Bi 11 ings (1962) found most alpine mineral soi Is on
the Beartooth PlateaLiin.Wyoming have the textural composition of a
gravelly, sandy loam. The gravel content varies somewhat but usually
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increases with depth; Clay content is conspicuously low in alp~ine
soils. 'Johnson and Billings (1962) report clay amounts ranged from
0.5% in a frost boil to i2% in an alpine bog soil.
Smith (1966) tested the nutrient status of two subalpine meadow
so i I si n the Med i c i neBQw Mounta ins. The two so i Is responde-d ~'i mt I arl y
to the addition of nutrlents. Nitrogen, potassium, and micronutrients
resulted in no increase in the yield of shoots, roots or shoots plus
roots. The add it i on of phosphorous, however, resu I ted in about..a 100%
increase in root yield and 60% increase in shoot yield, which.suggests
that phosphorus is a limiting factor.
Thilenius (this study) studied the soils on Libby Flats and on
the west slope of Medicine Bow Peak (see p. 24 for locations). He
found considerable pedogenic development at both sites, with the sola
(A and B horizons together) ranging from 6 to 38 cm deep. The sola
at the Libby Flats site was medium-textured with up to 40% stones,
while the other site had finer textured and generally stone-f~ee sola.
Both soils were well-drained, though short-term saturation was obvious
on Libby Flats in the spring. On Libby Flats the boundary between
dark upper horizons and the light subsurface horizon wa~ abr~pt.

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