Sagebrush steppe community response to low-rate tebuthiuron treatment: implications for rangeland and wildlife management.
Class
Article
Department
Wildland Resources
Faculty Mentor
Kari Veblen
Presentation Type
Oral Presentation
Abstract
The herbicide tebuthiuron is often used by range managers for controlling Wyoming Big Sagebrush (Artemisia tridentata ssp. wyomingensis). Because its efficacy in reducing mature shrub cover is widely documented, our study focused on the herbicide's effect on A. tridentata during immature life stages. We followed a t-test design to compare control plots to those treated with tebuthiuron at a low application rate at an established research site near Bear Lake, Utah. First, we measured A. tridentata seedling emergence from seed rain traps between treated and control plots. We also tracked A. tridentata seedling emergence and forb/grass seedling emergence from the seed bank of treated and control plots. Finally, we compared A. tridentata densities at four age classes from 2013 and 2014 in treated and control plots. Results indicate that this low application rate of tebuthiuron significantly reduces A. tridentata seedling emergence from seed rain, but does not decrease emergence from the seed bank. We also found that mature shrub densities decreased with treatment while young A. tridentata densities increased. These results suggest that low rates of tebuthiuron can be used to shift A. tridentata demographics from dominance of mature sagebrush to a greater amount of structural and life stage heterogeneity. This strategy can be utilized to achieve both livestock grazing and wildlife conservation objectives. By thinning mature sagebrush, the forb and grass component of the community will likely increase for improved livestock and wildlife forage. Simultaneously, sage grouse habitat is conserved by retaining some A. tridentata in the community. By utilizing low rate applications of tebuthiuron, managers can reap benefits of increased forage for livestock, sage grouse, and other wildlife without making drastic alterations to ecosystem functions.
Start Date
4-9-2015 10:00 AM
Sagebrush steppe community response to low-rate tebuthiuron treatment: implications for rangeland and wildlife management.
The herbicide tebuthiuron is often used by range managers for controlling Wyoming Big Sagebrush (Artemisia tridentata ssp. wyomingensis). Because its efficacy in reducing mature shrub cover is widely documented, our study focused on the herbicide's effect on A. tridentata during immature life stages. We followed a t-test design to compare control plots to those treated with tebuthiuron at a low application rate at an established research site near Bear Lake, Utah. First, we measured A. tridentata seedling emergence from seed rain traps between treated and control plots. We also tracked A. tridentata seedling emergence and forb/grass seedling emergence from the seed bank of treated and control plots. Finally, we compared A. tridentata densities at four age classes from 2013 and 2014 in treated and control plots. Results indicate that this low application rate of tebuthiuron significantly reduces A. tridentata seedling emergence from seed rain, but does not decrease emergence from the seed bank. We also found that mature shrub densities decreased with treatment while young A. tridentata densities increased. These results suggest that low rates of tebuthiuron can be used to shift A. tridentata demographics from dominance of mature sagebrush to a greater amount of structural and life stage heterogeneity. This strategy can be utilized to achieve both livestock grazing and wildlife conservation objectives. By thinning mature sagebrush, the forb and grass component of the community will likely increase for improved livestock and wildlife forage. Simultaneously, sage grouse habitat is conserved by retaining some A. tridentata in the community. By utilizing low rate applications of tebuthiuron, managers can reap benefits of increased forage for livestock, sage grouse, and other wildlife without making drastic alterations to ecosystem functions.