There has been increasing concern that training on military lands results i
n excessive soil erosion, ecosystem degradation, and loss of sustainable tr
aining resources. Vegetation structure has been shown to play a role in soi
l surface stabilization by reducing shear stress caused by wind force. A st
udy at the Idaho Army National Guard training facility at Orchard Training
Area (OTA), Ida. assessed the effect of simulated M1A2 Abrams battletank ma
neuvers on grassland plant canopies and soil erodibility. The point-interce
pt method was used to estimate vertical vegetation structure before and aft
er tracking. A portable wind tunnel was used to measure threshold wind spee
ds (TWS) associated with different numbers of tank passes and soil mass rem
oved by wind. Results indicated that significant damage occurred to vertica
l vegetation structure as the number of passes increased. Threshold wind sp
eed, an indicator of soil surface stability, significantly decreased with t
racking and eroded soil mass significantly increased. Positive correlations
existed between vegetation parameters and threshold wind speed. Soil loss
was negatively correlated with vegetation parameters. Results indicated tha
t the decrease of vertical vegetation structure led to a decrease in thresh
old wind speed. This decrease in threshold wind speed was the result of red
uced soil surface protection by vegetation. Decreased surface protection al
so resulted in increased soil loss. Results from this work confirmed that v
egetation plays a major role in reducing shear stress on the soil surface.
Predictions for soil loss at Orchard Training Area resulting from the numbe
r of M1A2 passes are made using linear models. A critical tracking threshol
d of 4 passes was estimated based upon model output and average local wind
speeds for Orchard Training Area.