Vegetation Management Alternatives on Electric Transmission Line Rows in North-Central Louisiana: Four Year Results

Charles E. Rowell, Kenneth W. Farrish, and James M. Dyer

Alternative vegetation management techniques were evaluated on two electric transmission rights-of-way (ROW) in north Louisiana over a four-year period. The objective of the work was to test techniques that select against trees, while allowing as many other plants to remain as possible. Comparisons were made between blade plowing and a mowed-only control, with follow-up treatments of burning, selective spot foliar herbicide application, and burning with selective spot foliar herbicide application. Blade plowing significantly reduced the number of tall tree stems compared to the mowed-only control. Spot herbicide application, especially in conjunction with blade plowing, was also very effective. Burning, however, did not reduce tall tree numbers. Generally, the follow-up treatments on the control plots (mowed only) had more trees with more stems of greater height than the same follow-up treatments on the blade plowed plots. Within site variability was extremely high at the Dubach site and analysis of variance indicated no significant difference among the follow-up treatments, although trends in reduction in mean tree numbers and size over the control were noted for the blade plow only, the blade plow with herbicide, and the blade plow with herbicide plus burning combinations. At both the Dubach and Simsboro sites, burning only, and blade plowing with burning were the least effective in reducing tree numbers, tree mean height, and cumulative tree height growth. Plant biodiversity was largely unaffected by all of the treatments, and the ratios of monocots to herbaceous dicots were also unaffected.

Keywords: Biodiversity, vegetation management, burning, selective spot foliar herbicide application, imazapyr, triclopyr, blade plow, woody root management, right-of-way