Challenges in rehabilitating extremely arid habitats; a case study: dry lake valley

Authors: Clements, Darin - Charlie; Harmon, Daniel - Dan

Submitted to: The Progressive Rancher
Publication Type: Popular Publication
Publication Acceptance Date: 2/18/2022
Publication Date: 3/7/2022
Citation: Clements, D.D., Harmon, D.N. 2022. Challenges in rehabilitating extremely arid habitats; a case study: dry lake valley. The Progressive Rancher. 22(3):12-14.

Interpretive Summary:

Technical Abstract: 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. We recorded the habitat at Dry Lake Valley of eastern Nevada as 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. The site was treated with soil-active, pre-emergent herbicides on replicated randomized plots with Plateau (Imazapic) @ 6 oz/ac rate and Landmark XP (Sulfometuron-Methyl) @ 1.75 oz/ac rate to control invasive annual species such as cheatgrass in 2016/2017 and 2017/2018 to replicate years as well. We also investigated native, introduced and native/introduced seed mixes on treated and untreated plots. Precipitation received in 2017/2018 (year 1, seedling year) was 4.9" while year 2 received 10.4" (2018/2019, year 2 seedling year). In September 2019 the survivability and establishment of seeded species in the Introduced, Native and Introduced/Native seed mix plots for year 1 was 0.80/ft², 0.40/ft² and 0.70/ft², respectfully for plots seeded in 2017. Plots seeded in 2018, year 2, resulted in initial average seedling densities of 2.5/ft² in the Introduced plots, 0.95/ft² in the Native plots and 2.4/ft² in the Introduced/Native seed mix plots. Control plots averaged 2.30/ft² in the Introduced plots, 1.4/ft² in the Native plots and 2.8/ft² in the Introduced/native seed mix plots as recorded in May 2019. In May 2020, seedling survivability and establishment in the year 2 plots decreased to 1.3/ft², 0.60/ft² and 1.3/ft² in the herbicide treated Introduced, native and Introduced/Native seed mix plots, respectfully, and 1.2/ft², 0.70/ft² and 0.90/ft² in the control plots. Prior to treating these plots with soil-active, pre-emergent herbicides to control invasive annual species, and seeding the plots to separate seed mixes, the sites average perennial grass density was 0.14 perennial grasses/ft², whereas following the herbicide and seeding applications the site averages 0.90 perennial grasses/ft² (39,200/acre), a 600% increase, far surpassing the goal of 0.40 perennial grasses/ft².