Author
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Clements, Darin - Charlie |
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RUBALD, TIM - Nevada Department Of Conservation And Natural Resources |
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Submitted to: The Progressive Rancher
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/30/2017 Publication Date: 4/10/2017 Citation: Clements, D.D., Rubald, T. 2017. Plant materials and methodologies for Great Basin rangelands. The Progressive Rancher. 17(4):36-37. Interpretive Summary: Great Basin rangelands are in high demand for technology to improve restoration/rehabilitation practices. The Nevada Section, Society for Range Management held a symposium in Sparks, Nevada with an expert panel of presenters to share their many years of research and experience in soil, weed, range and plant science. The accidental introduction and subsequent invasion of annual grasses, particularly cheatgrass, has truncated succession and increased the chance, rate, spread and aseason of wildfires throughout the Intermountain west. The establishment of long-lived perennial grasses is the best known method at suppressing exotic-invasive annual grasses like cheatgrass and medusahead. Each presenter made it very clear on the importance of weed control before trying to restore or rehabilitate degraded rangelands. Burning, mechanical and chemical treatmnets were all discussed. Soil active herbicides loke Landmark decreased cheatgrass above-ground densities by more than 99%, which opened up a short window of opportunity to establish long-lived perennial grasses in the absence of cheatgrass competition. The establishmentof long-lived perennial grasses such as crested wheatgrass and bluebunch wheatgrass established at high enough densities, 0.6-1.2/ft², to significantly decrease cheatgrass desnities and associated fuel loads. Perennial grass selections have been improved greatly in some cases; Snake River wheatgrass improved by 74%. Introduced grasses crested wheatgrass and Siberian wheatgrass outperformed native perennial grasses bluebunch wheatgrass and squirreltail, but the breeding program is narrowing this performance gap. Monitoring of weed invasions, fires, seeding projects and wildlife counts all gained attention of using innovative appraoches by using drones that can present high resolution data to improve data resource managers need, especially in hard to get to locations. The ability of resource managers to hear first hand on the experiences of nearly a century and half that the presenters have under their belts should not be taken for granted. These presenters presented years of research and experience that if used properly will lead to improved restoration/rehabilitation success rates on Great Basin rangelands. Technical Abstract: The Nevada Section, Society for Range Management held a winter meeting/symposium January 2017 in Sparks, Nevada. Nearly a century and half of research and experience was presented by scientists in the field of soil science, range and weed science and plant genetics. The ability of resource managers to restore/rehabilitate rangelands is very difficult on arid rangelands. Nevada is the most arid state and much of its arid rangelands recieve less than 8" annually, making it very difficult to find desirable plant materials that can germinate, emerge, establish and persists in these harsh environments. Plant geneticists have been hard at work improving native and introduced plants through selections and breeding programs. Germination, seedling vigor, establishment and persistence are the major traits selected for. Nonetheless, the knowledge of soil properties, weed control and seed and seedling ecology are instrumental if restoration/rehabilitation efforts are going to be successful. Selections of bluebunch wheatgrass, squirreltail and Indian ricegrass have come a very long way, but with that said introduced perennial grasses such as crested wheatgrass and Siberian wheatgrass performed better than the natives. Even though some of these native selections improved in germination and emergence rates, establishment rates fell of as these selections did not persist and decreased by nearly 30% in a very short 5-year period. Native selections actually performed better and showed longer persistence when seeded with Siberian wheatgrass in their trials. Such selections as Snake River wheatgrss has shown a 74% increase in establishment through the breeding programs. Weed control practices such as burning, chemical and mechanical treatments are all tools used by resource managers. Research data yielded that burning by itself is not successful, but in combination with certain soil active herbicides the establishment of long-lived perennial grasses increased. Burning initially decreased cheatgrsass, but by year-3 cheatgrass was more than 15/ft², which is not effective. Burning in the early fall, followed a herbicide application of Plateau @ 8 oz/acre rate, fallowed for 1-year and seeded to perennial grasses resulted in nearly 1 perennial grass per ft². Soil active herbicides such as Plateau, Landmark and matrix are performed well at controlling cheatgrass and opening a short window for seeding efforts and subsequent sedling emergence and establishment of long-lived perennial grasses. The establishment of native versus introduced species in treated areas was also investigated. Native species, bluebunch wheatgrass and squirreltail, established at 0.22/ft² compared to 0.7/ft² for crested wheatgrass. The fact that the native species demand higher levels of precipitation zones significantly limits their ability to provide cheatgrass suppression and decrease the chance, rate, spread and season of wildfires on millions of acres of rangelands. Research geneticists continued effort at breeding native selections may in fact imporove the traits neccesary to improve native perennial grass germination, emergence, establishment and persistence. |
