User's Guide for Estimating Allowable Use of Tracked Vehicles on Nonwooded Military Training Lands

摘要

To avoid excessive soil erosion and insure the continued availability of U.S. military training lands, there must be a basis for estimating allowable levels of sustained tracked vehicle use. The allowable use management objective can be attained by establishing permanent line transects in areas representative of each ecological response unit. The point-intercept method is employed along each line transect to determine botanical composition, amounts of ground and canopy cover for untracked and tracked points, and percent of the surface tracked and untracked. Soil samples are collected to determine soil erodibility. For each vehicle type, estimates are made of the average cross-country distance traveled per day (surface coverage is computed by adding the width of the tracks times distance traveled). Estimates are made of the average number of years for tracked areas to regrow vegetation cover equivalent in C-value for the universal soil loss equation to untracked areas and the average number of years that a track mark remains visible. Allowable use is calculated in tracked vehicle days per year (TVDs/year) for military trainers and percent surface disturbance for land managers. Reprints. (sdw)