Challenges in Rehabilitating Extremely Arid Habitats A Case Study: Dry Lake Valley
By Charlie D. Clements and Dan N. Harmon
It is well documented how difficult of a task resource managers have when attempting to restore or rehabilitate disturbed or degraded habitats throughout the Great Basin. These challenges are multiplied many times over when attempting to restore or rehabilitate severely arid habitats. Rangeland revegetation has been around for more than a century and many experienced researchers have cautioned future researchers on the numerous frustrations that lay ahead when addressing the restoration or rehabilitation of range sites that are not only degraded, but also are severely limited by lack of effective amount and periodicity of annual precipitation. Sites that regularly receive less than 7” of annual precipitation often lack the necessary precipitation to achieve any level of revegetation success. Researchers have reported that favorable conditions to establish seeded plants in these arid environments may only occur 1 out of every 4 years, while others have reported the
necessary conditions needed to recruit natural or artificially induced seedling recruitment vegetation may only occur 1 or 2 years out of every 15 years (Fig. 1). Nonetheless, many of these habitats are critical to wildlife as well as sustainable grazing practices. In 2013, we were approached by the US Department of Interior, Bureau of Land Management (USDIBLM) to investigate revegetation practices that could possibly reduce the exotic and introduced annual grass, cheatgrass, while at the same time improving grazing resources. Our first investigation to the site took place in June 2013 and we recorded that the habitat was a degraded winterfat/Indian ricegrass community, while the community was dominated by cheatgrass and Russian thistle with a sparse presence of winterfat, Indian ricegrass, galleta grass and sand drop seed. In 2015, a 5-acre exclosure was constructed to
aid our research efforts on testing two soil-active, pre-emergent herbicides, Plateau (Imazapic) and Landmark XP (Sulfometuron-Methyl) to control invasive annual species such as cheatgrass. Pretreatment data collection revealed a remnant perennial grass population of 0.14 perennial grasses/ ft² (6,070/acre) dominated by Indian ricegrass and galleta grass with a shrub population of 0.03/ ft² (1,335/acre) dominated by winterfat. The site appears to be very static in amount and periodicity of precipitation, nonetheless we set out with a goal of increasing the perennial grass density to 0.40/ ft², to aid in the suppression of cheatgrass and significantly improve foraging resources. In the fall of 2016, we set up 12 randomized 60’ x 150’ plots which included herbicide applications with Plateau @ 6 oz/acre rate, Landmark @ 1.75 oz/acre rate and control plots (no herbicide application). Plots were sprayed in the fall of 2016, fallowed for 1 year and then seeded the following fall.
Figure 1. Dry Lake Valley, located in eastern Nevada, represents habitats that are severely limited due to extremely frequent drought conditions.
12 MARCH 2022
The Progressive Rancher
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