Ft Hood TX troop training activities cause severe rangeland disturbance, loss of vegetative cover and soil erosion. Studies have been initiated to identify best management practices (BMP) to reduce the impacts of training exercise. The BMPs include sediment traps (modified stock ponds), dedicated roadways (for track vehicle use), and revegetation. Revegetation efforts include reseeding with native and introduced grasses and forbs, and identification of species which can be used as vegetative hedges for erosion and runoff control. The Fort Hood area is on the northern edge of the Edwards Plateau and west of the Balcones Escarpment. Plant communities are characterized as midgrass prairie, riparian and canyon systems. Climax vegetation of the prairie areas includes big bluestem, little bluestem, indian grass, switchgrass, sideoats grama, Canada wildrye, Virginia wildrye, buffalograss, Texas grama, threeawn species, liatris species, blackfoot daisy, yucca species, prickly pear and nolina species. Shrub and tree species include Ashe juniper, honey mesquite, Texas ash, bigtooth maples, sugar hackberry, elm and willow. As in many locations throughout the world, Ashe juniper and mesquite have moved from the riparian areas and slopes onto the prairie areas.

House Creek , one of the perennial creeks that flows through and drains the Ft Hood, TX rangelands. During periods of no rainfall the water is clear. Runoff water from the surrounding rangelands following rainfall is heavily laden with soil particles.

Ft Hood, TX rangeland traversed by track vehicles during training exercises. Soils in this area are shallow, underlain by fractured limestone. Note lack of vegetation in the foreground and the tracks on the hills in the background created by training exercises. The brush species is Ashe juniper (Juniperus ashei) or mountain cedar. Although the herbaceous species are sparse, they include little bluestem and sideoats grama, which are considered 'good' rangeland species as well as less desirable King Ranch bluestem, threeawn species and Texas grama.

Track vehicle activities cause extreme disturbance to the soils. Maneuvers consist of several phases: a) aggregating at the staging area, b) executing the training exercise and c) aggregating at the post training site. While executing the training exercise, the vehicles move singly or in small groups across the terrain, sometimes using the same path and other times creating their own path. Often times a track is used frequently in subsequent training events. This leads to loss of vegetation followed by channelization and erosion. When moving between training areas or before and after the training exercise, the troops use dedicated roadways to decrease the impacts to the area. These dedicated paths and roadways have been specifically engineered for track vehicle use.

A dedicated roadway for tanks.

Sedimentation of an ephemeral channel following a runoff event. Rain waters flow overland using the 'path of least resistance', which is frequently tracks left by the track vehicles. Sedimentation occurs wherever the water slows.

Evidence of the impact of the training activities on the soil and vegetation on the Ft Hood TX rangelands. The white areas are exposed subsoils resulting from the loss of the vegetative cover and soil due to training activities.

Sedimentation and runoff showing erosion on Ft Hood TX rangelands, due to troop training activities.

Rangeland on Ft Hood TX in the troop training area. Although this is a rather 'pretty' scene, due to soil disturbance, the vegetation is comprised of annual and perennial 'weed' species such as broom weed, buffalo burr, giant ragweed, western ragweed and snow-on-the-prairie.

Ft Hood TX rangeland traversed by track vehicles during training exercises. Note the extreme soil disturbance in the foreground and gullies in the background. Overland runoff utilizes the paths created by the track vehicles, accentuating channelization and erosion.

Sediment traps are stock ponds which have been constructed to contain runoff waters and slow the flow rate. When runoff waters enter the trap, the flow rate decreases allowing suspended sediments to settle to the bottom of the trap. The water is slowly drained from the trap so that during the next rainfall and runoff event the maximum amount of water can again be retained and its sediment load decreased.

July 13, 2000
Dennis Hoffman, Project Leader;
Steve Dagitz, Webmaster