WMOD00409

• Contract/Permit #: 1-07-81-V0175
• Title: State of Montana Activities in the High Plains Cooperative Program: 1981-1983
• Date: 6/30/1983
• State: MT
• Weather Modification - Doc Type: Report

APPENDIX B

WATER EFFECTS ON WIND EROSION 8USCEPTIBILITY OF
THREE EASTERN MONTANA GRASSLANDS

by

Brent M. Haglund

Introduction

Both society in general and the agriculturists who depend upon the land's
productivity are concerned with the environmental consequences of grassland
management as well as its economic aspects. Episodes of severe wind erosion
have produced action for soil conservation in North America (Sheridan, 1981).

The northern Great Plains of this continent, including much of Montana, is
one of several geographic areas where soil productive potential has been
greatly lowered by wind erosion. Both wind and water erosion increase sharply
during dry weather (Soil Conservation Service, 1982). Diminished protective
plant cover exposes more ground, and increasing surface wind speeds add to the
transport of dry clay and silt particles (Fuchs, 1979).

The potential for wind erosion is affected by soil moisture (the most
ecologically important result of precipitation) and community types of
grasslands established by land management practices of ecosystem succession
(Buckhouse et al., 1980). Land management practices can alter wind erosion
potential (Troeh et al., 1980).

Cultivation is the major factor in soil moisture, because it exposes soil
to the wind, producirLg susceptibility to wind erosion. Range p10wi.ng and
reseeding to establish tame pastures for spring grazing have not bE!en assessed
for wind erosion potentials, but might increase it by producing mOI'e bare
ground, destroying cryptogam mats, and introducing species with less resistance
to wind movement (Fuchs 1979; Marshall 1971).

Climax or more mature communities are believed to be more resistant to
nutrient losses than early seral stage communities (Odum 1969; Vitousek et al.
1979), and so may be less susceptible to wind erosion. Native northern Great
Plains grasslands tend to include both relatively high-yielding C3
photosynthetic pathway species (e.g., Agropvron, smithii and St1pa ~!.) and
more water-use efficient, but perhaps lower-yielding C4 type species such as
Bouteloua gracilis and BUch10e dactv10ides (KUchler, 1964).

Site Descriptions

The experiments were done in 1979 at three sites within 15 km of Miles
City, Montana, on the USDA Livestock and Range Research Station. A.t Miles City
the past 30-year average annual precipitation is 355 mm. More detailed weather

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