Source: UNIVERSITY OF NEVADA submitted to
REHABILITATION OF A SALT-DESERT SHRUB COMMUNITY:HERBACEOUS RESPONSE TO SHRUB REMOVAL AND ESTABLISHMENT OF FORAGE KOCHIA AND OTHER PLANT SPECIES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0222741
Grant No.
(N/A)
Project No.
NEV05356
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Jul 1, 2010
Project End Date
Jun 30, 2014
Grant Year
(N/A)
Project Director
Stringham, T.
Recipient Organization
UNIVERSITY OF NEVADA
(N/A)
RENO,NV 89557
Performing Department
Ag Nutrition and Vet Sciences
Non Technical Summary
Vast areas of semiarid rangelands in the western U.S. are severely disturbed and subsequently infested with weeds like cheatgrass and halogeton. Wildfires burning in plant communities dominated by woody fuels can be difficult to control, making fuels reduction desirable. Due to post-treatment weed invasion, the effectiveness of control methods for woody plant abundance in salt-desert shrub communities may be reduced by practices that involve soil surface disturbance. The application of the bacteria Pseudomonas fluorescens D7 (PfD7), which has been shown to reduce the density, shoot mass, and number of seeds of cheatgrass needs tested. Reseeding disturbed rangelands with genetically improved plant materials that are competitive enough to replace existing undesirable vegetation is often the most plausible and economically feasible way to reclaim such sites. Forage kochia and several non-native grasses have been documented to be highly competitive with annual species, like cheatgrass, by reducing their establishment and spread and having the ability to disrupt the spread of wildfires. Green fuel breaks of adapted forage kochia varieties and cool-season grasses may be a valuable tool in saving intact Great Basin habitat and for rehabilitation of burned, degraded habitat by reducing the spread of wildfires. This project will determine the response of the grass understory to shrub removal, the effectiveness of herbicides in reduction of invasive annual grass after disturbance, and the effectiveness of seeding forage kochia and desirable grasses for rehabilitation of salt-desert shrub communities. Immigrant forage kochia, experimental forage kochia from Kazakhstan and Uzbekistan, and selected grasses (crested and Siberian wheatgrass, intermediate and tall wheatgrass, Russian wildrye, Basin wildrye, creeping wildrye, wildrye hybrids, salt grass, and alkali sacaton) will be compared for their ability to establish, persist, and act as green fuel fire breaks in a salt-desert shrub community. Plants will be established both by transplanting greenhouse started seedlings and by seed at two locations. Additionally, to determine the effects of shrub removal on understory and soil response in a salt-desert shrub community, the following treatments will be tested: shrub removal only, shrub removal with imazapic (herbicide) application, shrub removal with application of PfD7, and shrub removal with application of imazapic and PfD7. This project has the potential to identify plant materials and management practices that would significantly increase the protection and rehabilitation success of salt-desert shrub communities in Nevada and the Great Basin. Knowing the effects of fuels reduction on native herbaceous vegetation within these communities may decrease the cost and increase the success of fuel breaks while simultaneously increasing habitat values and forage for wildlife and livestock. In addition, the seeding trials will increase knowledge for revegetation of these sites after disturbance, ultimately reducing costs of rehabilitation and increasing the productivity and nutritional quality of rangelands intended for livestock and wildlife grazing.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1030710107020%
1030710114020%
1210710107030%
1210710114030%
Knowledge Area
103 - Management of Saline and Sodic Soils and Salinity; 121 - Management of Range Resources;

Subject Of Investigation
0710 - Desert and semidesert shrub land and shinnery;

Field Of Science
1070 - Ecology; 1140 - Weed science;
Goals / Objectives
The goals of this project are to determine the potential of shrub removal, reduction of annual grass after disturbance, and seeding of forage kochia and grasses for rehabilitation of Great Basin salt-desert shrub communities. Immigrant forage kochia, experimental forage kochia germplasm, and selected grasses (crested and Siberian wheatgrass, intermediate and tall wheatgrass, Russian wildrye, Basin wildrye, creeping wildrye, wildrye hybrids, salt grass, and alkali sacaton) will be compared for their ability to establish, persist, and act as green fuel breaks. The objectives of this project are to determine: 1. The influence of shrub removal on diversity and abundance of herbaceous species and soil nutrient and water availability. 2. The effectiveness of Pseudomonas fluorescens strain D7 (Pf D7) and imazapic (Plateau)applications to limit annual grass invasion following shrub removal. 3. The establishment and persistence of forage kochia and several grasses. 4. If forage kochia will expand beyond the seeded area. 5. Plant traits that enhance seedling establishment and persistence, and the most efficient seeding protocol for the salt desert ecosystem. Tentative Schedule: FY 2011: Shrub removal study: Plot layout, collect baseline vegetation data, remove shrubs and apply imazapic and Pf D7. Build fence around both locations. Seeding Study: Install weather stations. Start space-plants (3-4,000 specimens) in greenhouse. Build fence around both locations. Conduct site preparation (roto-tilling, herbicide application). Plant space-plants and seeded trials. FY 2012: Shrub removal study: Collect vegetation and soil data. Seeding Study: Take seedling establishment data on seeded trials at both sites. Take forage samples for moisture content. FY 2013: Shrub removal study: Collect vegetation and soil data. Assess frequency of future data collection. Analyze data and begin working on publications. Seeding Study: Collect plant persistence data, forage and seed yield data on seeded and spaced-plant trials. Conduct seed threshing and deep seeding evaluation. Conduct forage quality. FY 2014: Shrub removal study: Submit manuscripts for peer-reviewed publication. Seeding Study: Collect plant persistence data, forage and seed yield data on seeded and spaced-plant trials. Conduct seed threshing and deep seeding evaluation on selected grasses. Conduct forage quality. Begin writing manuscripts for submission to a peer-reviewed journal.
Project Methods
Shrub Removal Study: The study design will be a randomized complete block using the following treatments: 1) control, 2) shrub removal, 3) shrub removal and imazapic, 4) shrub removal with Pf D7, and 5) shrub removal with imazapic and Pf D7. Treatments will be replicated on two ecological sites, 5 times and applied to 5 by 5 m plots. Response data will be analyzed using a repeated measures analysis of variance model with repeated time. Imazapic (87.5 g ai/ha) and Pf D7 (108 cfu/m2) will be applied to plots using hand-held sprayers. Vegetation abundance, basal gap, cover and density will be monitored along 3 permanent 3 m transects in each plot. Shrub density will be measured using a 1 m belt transect. Two pairs of nutrient probes will be located within each plot. Soil samples will be collected at each plot in March, April, May and June of 2011 and 2012 for gravimetric water content. Seeded and Spaced-Plant Study: Immigrant forage kochia and experimental forage kochia and selected native and non-native cool and warm season grasses will be used for both spaced-plant plots and as seeded plots. Research plots will be established on two ecological sites in a randomized complete block design with a minimum of four replications. Spaced-plant plots will consist of 20 plants spaced 0.5 m apart with 1 m spacing between rows. Seeded plots will be sown by broadcasting or 5-row cone-seeder in 1.25 m wide by 5 m long plots. Data will be analyzed using the MIXED model procedure of SAS. Frequency of the seeded forage kochia and grasses, as well as invading plants will be monitored during the spring for three years using the frequency grid method. Height, growth, and moisture content of the seeded species will be evaluated by measuring and clipping 1 by 1 m sub-samples. Spaced-plants will be used to evaluate persistence and survival of individual plants of forage kochia and grasses. Plants will be scored as dead or alive each summer, and height, growth, and moisture content will be evaluated. Seeds will be harvested from the spaced-plants and screened for germination and seedling establishment. Samples for dry matter determination and forage quality will be dried at 60oC in a forced-air oven to a constant weight; ground in a Wiley and a Cyclone mill to pass through a 1 mm screen. Ground plant samples will be scanned with a Model 6500 near-infrared spectroscopy (NIRS) instrument. NIRS systems software will be used to calibrate an existing forage quality equation. Representative samples from each study not included in the calibration of the equation will be selected as a validation set for wet laboratory analysis. Samples used for calibration and validation will be analyzed for nitrogen using a LECO CHN-2000 Series Elemental Analyzer. Neutral-detergent fiber (NDF) and in-vitro true digestibility (IVTD) will be determined using procedures described by Goering and Van Soest (1970). Analysis for acid detergent fiber and NDF will be conducted for each forage sample using ANKOM-200 fiber analyzer and filter bag procedures. In-vitro dry-matter digestibility will be measured as the residue following a 48 hr in-vitro fermentation made with the ANKOM-200 Fiber Analyzer.

Progress 07/01/10 to 06/30/14

Outputs
Target Audience: Professional rangeland managers, scientists and the general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One graduate student and multiple undergraduate students had the opportunity to learn methods associated with agronomic field trials. Graduate student has completed their thesis at Utah State University (space-plant study). How have the results been disseminated to communities of interest? Results have been presented at the NV Society for Range Management meeting in June 2014. Additional papers will be presented at the national meetings of the Society for Range Management in February 2015. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The potential of shrub removal and the reduction of annual grass after disturbance using Pf D7 and imazapic were evaluated. Forage kochia and a suite of grasses were coated individually and into pellets and seeded along with control plots of uncoated seeds to determine the efficacy of coating technology in increasing the emergence and establishment of these species within the salt desert envirionment. Soil chemistry was determined within the rooting zone of grasses during 2012. Space-plant study of a variety of species including forage kochia was completed in 2013. Due to drought conditions during the 2012-2013 growing seasons the space-plant garden and coated seeding trials had limited success. Manuscripts are currently in production.

Publications


    Progress 01/01/13 to 09/30/13

    Outputs
    Target Audience: Public and private land managers and the scientific community Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Submit manuscripts to the Nevada Agriculture Experiment Station publication/Rangelands publication.

    Impacts
    What was accomplished under these goals? At the plot scale, preliminary data suggest that density of perennial grasses, mainly alkali sacaton (Sporobolus airoides (Torr.) Torr.) and saltgrass (Distichlis spicata (L.) Greene), may have been increased with shrub removal, but that increase was not amplified by additional treatment with Imazapic or D7. Density was highest for the shrub removal treatment in 2012, and values appeared to increase for this treatment, and for the control treatment, relative to 2011. Values did not increase between years for the shrub removal plus Imazapic or D7 treatments suggesting the possibility of inhibitory effects of these treatments on perennial grass species. Cover of annual grasses was, predictably, lowest for the Imazapic treatment in 2011. Values continued to decrease for this treatment in 2012, suggesting that our initial application of the treatment may have been too late in in fall 2010, which is consistent with field observations indicating emergence of some cheatgrass seedlings at time of spraying. Removal of shrubs alone did not impact cheatgrass cover, and co-treating with D7 did not appear to substantively reduce cheatgrass cover; in fact, cheatgrass cover was numerically highest for the shrub removal plus D7 treatment in 2011. At the microsite scale, our preliminary data suggest that shrub removal may act to increase perennial grass density in undercanopy locations. In 2011, perennial grasses were only recorded in section 1 (nearest shrub base) with shrub removal plus Imazapic treatment. In 2012, perennial grasses were absent in sections 1 and 2 for the control treatment, but present in section 2 for the shrub removal and shrub removal plus Imazapic treatment. Perennial grasses in control plots appear to be concentrated in the area of the shrub drip line (transition area between undercanopy and interspace microsites), whereas shrub removal appears to spatially expand the area of occupancy for perennial grasses. In contrast to perennial grasses, annual grasses were more spatially dispersed in both years. Shrub removal apparently freed-up resources in undercanopy locations that were used by annual grasses (i.e., given the initial -2011- dis-proportionately high abundance of annual grasses in these locations), but this trend had dissipated, if not reversed in 2012. Initial data (2011) suggest that Imazapic was less effective in undercanopy locations. This was likely in association with initially high soil carbon values for the undercanopy locations (data not presented here). Carbon can act to neutralize the effects of Imazapic.

    Publications


      Progress 01/01/12 to 12/31/12

      Outputs
      OUTPUTS: Seeding Study: Data collection on seedling emergence and establishment was completed between April and September of 2012. A similar seeding will be planted in the spring of 2013 with seedling emergence, establishment and biomass will be collected. Shrub Removal Study: Data collection and analysis are currently in progress. PARTICIPANTS: Tamzen Stringham, PI coordinated project implementation and participated in field data collection. Erica Freese conducted field data collection and data entry, and served as supervisor to the field technician. Mark Weltz and Christo Morris, ARS-Reno, collected data from the weather station. Charlie Clements, ARS-Reno, applied herbicide for weed reduction. Matt Madsen, ARS-Burns, coated and agglomerated seeds for the year 2 of the seeding trial. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

      Impacts
      This project is still in progress and results are not available at this time.

      Publications

      • No publications reported this period


      Progress 01/01/11 to 12/31/11

      Outputs
      OUTPUTS: Seeding study: During 2011, the seeding trials were implemented. Prior to seeding, the study plots were treated with the herbicides glyphosate and 2,4-D for control of annual weeds. Herbicide treatment was applied by Charlie Clements with the USDA-ARS in Reno, Nevada. Plant species used in the seeding experiment were: Achnatherum thurberianum, Agropyron desertorum, Artemisia tridentata ssp. wyomingensis, Elymus elymoides, and Achnatherum hymenoides. Seeding treatments included: 1)Seeds coated with diatomaceous earth and agglomerated by species (~10 seeds/agglomerate); 2)seeds uncoated, seeded in clumps, 3)seeds uncoated, single seed planting with ~24 seeds/foot (did not include sagebrush); and 4)seeds coated, single seed planting with ~24 seeds/foot (did not include sagebrush). Seed coating was conducted by one of our collaborators, Dr. Matthew Madsen, at the USDA-ARS in Burns, Oregon. Five plots with treatments randomly assigned to each row were hand sown in November 2011. Data collection on seedling emergence, establishment, and biomass will be collected in 2012. Shrub removal study: data collection and data analysis are currently in progress. PARTICIPANTS: Tamzen Stringham, P.I. coordinated seeding project design and implementation. Erica Freese help with project design and conducted the seed planting. Matthew Madsen, USDA-ARS in Burns, Oregon conducted the seed coating for the seeding project and helped with project design. Mark Weltz and Christo Morris, USDA-ARS in Reno, Nevada did the data collection for the weather station. Charlie Clements, USDA-ARS in Reno, Nevada applied the herbicide treatments. TARGET AUDIENCES: Rangeland managements, federal agencies, private land owners PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

      Impacts
      This project is still in progress and no results are available at this time.

      Publications

      • No publications reported this period


      Progress 07/01/10 to 12/31/10

      Outputs
      OUTPUTS: During 2010, the fencing was installed around the test plots. The shrub study started with plot layout and collection of baseline vegetation data. Subsequently, the shrubs were removed and imazapic and Pf D7 were applied to study plots. Additionally, a weather station was installed at the study site. During 2011, the seeding study will begin and the shrub removal study will continue with data collection. PARTICIPANTS: Tamzen Stringham, P.I. coordinated fencing activities. Mark Weltz and Christo Morris, USDA-ARS in Reno, NV installed the weather station. Chad Boyd with USDA-ARS in Burns, OR conducted the data collection, shrub removal, and treatment applications for the shrub removal study. TARGET AUDIENCES: Managers working with salt desert shrub ecosystems along with people who utilize these ecosystems for grazing, mining etc. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

      Impacts
      This project is currently in progress. No results are available at this time.

      Publications

      • No publications reported this period