Ecological Aspects of Herbicide Usage on Power Line Rights-of-Way

The effect of a herbicide-oriented vegetation management program on the diversity of vegetation in power line rights-of-way and the resulting vegetation's potential usefulness to wildlife was evaluated in three eco-regions of Alberta - The Dry Parkland/Prairie, the Moist Parkland and the Mixed Boreal zones. In herbicide treated areas, plant communities consisted of grasses, herbaceous forbes, shrubs and small trees. The proportion of plants in these fourgrowth forms was similar for plant communities in both the treated rights-ofway and the adjacent untreated areas for the Parkland zones.

In the Mixed Boreal zone, herbicide treatment favoured the proliferation of herbaceous forbes and grasses while discouraging understorey shrub growth. The herbicide treatment had little effect upon the diversity of plant communities that established in the Dry Parkland/Prairie zone but increased the diversity in the Moist Parkland and Mixed Boreal zones. The diversity increased due to a change in species richness. The wildlife food utilization value of the plant communities that developed on the treated rights-of-way was equal to that of untreated areas in the Dry Parkland/Prairie zone, but was greater than that of untreated areas in the Moist Parkland or Mixed Boreal zones.

An examination of plant species composition and abundance under various right-of-way maintenance regimes under and near TransAlta Utilities (Alberta, Canada) distribution lines...