Seeding Native Plant Following Fire
in Wyoming Big Sagebrush Shrub-steppe
Jeff Ott and Nancy Shaw
U.S. Forest Service, Rocky Mountain Research Station, Boise, ID
Research Collaborators:
Rob Cox (Texas Tech U.), Mike Pellant (BLM),
Bruce Roundy (BYU), Dennis Eggett (BYU)
Common Scenario in the Great Basin
Unburned vegetation
(Wyoming big sagebrush)
Fire
Exposed soil:
wind and water erosion;
dust and flooding risk
Cheatgrass Invasion
Annual vegetation:
diminished resource values, biodiversity,
wildlife habitat & ecosystem function;
increased risk of future fire
Common Scenario in the Great Basin
Unburned vegetation
(Wyoming big sagebrush)
Fire
Exposed soil:
wind and water erosion;
dust and flooding risk
Seeded Vegetation
Cheatgrass Invasion
Annual vegetation:
diminished resource values, biodiversity,
wildlife habitat & ecosystem function;
increased risk of future fire
Post-fire Seeding Techniques: Rangeland Drills
Conventional Rangeland Drill
Minimum-till Drill
(e.g. P&F Services Kemmerer)
(e.g. Truax RoughRider)
Disclaimer: Mention of products or trade names does not imply
endorsement by the U.S. Government
Seed Size Contrasts
‘Large’ Seeds
e.g. Bluebunch Wheatgrass
135,000 seeds/lb
‘Small’ Seeds
e.g. Wyoming Big Sagebrush
2,500,000 seeds/lb
Seeding depth: 1/4-1/2”
Drilling effective
Seeding depth: 1/16”
Drilling less effective
Post-fire Seeding Techniques: Broadcast Seeding
Aerial Broadcast
Drill-broadcast
Drilling and Broadcasting in Alternate Rows
Conventional drill
with drop-pipes & chains
Minimum-till drill
with imprinter units
Post-fire Seeding Study
Objective: Compare seeding treatments differing by:
• Drill Type
– Conventional
– Minimum-till
• Broadcast Method
– Drill-broadcast
– Aerial Broadcast
+ Control Treatments
– No drill, no seed
– Drilled but not seeded
Post-fire Seeding Study
Objective: Compare seeding treatments differing by:
• Drill Type
Fall aerial broadcast
Winter aerial broadcast
– Conventional
– Minimum-till
• Broadcast Method
– Drill-broadcast
– Aerial Broadcast
+ Control Treatments
– No drill, no seed
– Drilled but not seeded
• Aerial Broadcast Timing
– Fall (late Oct.-early Nov.)
– Winter (Jan.-early Feb.)
Post-fire Seeding Study
Objective: Compare seeding treatments differing by:
• Drill Type
Fall aerial broadcast
Winter aerial broadcast
– Conventional
– Minimum-till
• Broadcast Method
– Drill-broadcast
– Aerial Broadcast
+ Control Treatments
– No drill, no seed
– Drilled but not seeded
• Aerial Broadcast Timing
– Fall (late Oct.-early Nov.)
– Winter (Jan.-early Feb.)
Study Sites
• Four Wyoming big sagebrush sites in Idaho,
Oregon and Utah
• Burned 2007-2010
• Selection Criteria:
– Drillable terrain
– Shrub cover pre-burn
– Clean seedbed
Elevation: 910-1430 m (2985-4690 ft)
Mean Annual Precipitation: 222-286 mm (9-11 inches)
Soil Types: Silty to Loamy Aridisols, Ashy Glassy Mollisols, Sandy Entisols
Drill Seed Mix
(large seeds)
Bluebunch Wheatgrass
(Pseudoroegneria spicata)
Bottlebrush Squirreltail
(Elymus elymoides)
Indian Ricegrass
(Achnatherum hymenoides)
PLUS:
Thurber’s Needlegrass
(Achnatherum thurberianum)
Needle-and-thread
(Hesperostipa comata)
Basalt Milkvetch
(Astragalus filipes)
Munro’s Globemallow
(Sphaeralcea munroana)
Sulphur-flower Buckwheat
(Eriogonum umbellatum)
Broadcast Seed Mix
(small seeds)
Wyoming Big Sagebrush
(Artemisia tridentata spp. wyomingensis)
Rubber Rabbitbrush
(Ericameria nauseosa)
Western Yarrow
(Achillea millefolium)
Sandberg Bluegrass (Poa secunda)
Penstemon (Penstemon deustus/cyaneus/speciosus)
Species seeded and rates (pure live seeds [PLS] m-2)
Species – Cultivar/Germplasm/Source
Broadcast Seed Mix
Sandberg bluegrass (Poa secunda) – Mountain Home Germplasm
Seeding Rate (PLS m-2)
Mountain Glass
Saylor
Scooby
Home
Butte
Creek
91
91
91
100
Western yarrow (Achillea millefolium) – Eagle Germplasm
0
0
100
100
Rubber rabbitbrush (Ericameria nauseosa) – WY and UT sources
86
86
86
85
Scabland penstemon (Penstemon deustus) – N. Great Basin (pooled)
76
76
0
0
Blue penstemon (Penstemon cyaneus) – Lincoln Co., ID
0
0
76
0
Royal penstemon (Penstemon specious) – N. Great Basin (pooled)
0
0
0
15
262
234
234
250
Bluebunch wheatgrass (Pseudoroegneria spicata) – Anatone Germplasm
67
67
67
60
Indian ricegrass (Achnatherum hymenoides) – ‘Rimrock’
51
51
51
50
Bottlebrush squirreltail (Elymus elymoides) – Toe Jam Creek Germplasm
47
47
47
35
Munro’s globemallow (Sphaeralcea munroana) – Utah and Uintah Co., UT
93
93
93
40
Sulfur-flower buckwheat (Eriogonum umbellatum) – N. Great Basin (pooled)
8
11
11
0
Thurber’s needlegrass (Achnatherum thurberiaum) – S. Idaho (pooled)
0
0
0
30
Needle and thread grass (Heterostipa comata) – Millard Co., UT
0
0
0
20
Basalt milkvetch (Astragalus filipes) – Deschutes Co., OR
0
0
0
14
Wyoming big sagebrush (Artemisia tridentata) – multiple field sources
Drill Seed Mix
Methods
• Experimental Design
– Randomized complete block
– 5 blocks per site
– Treatments in 70 x 30 m plots
• Data Collection
– 1st and 2nd years post-treatment
– Density: ½ or 1 m2 quadrats
– Cover: Line-point intercept
• Statistical Analysis
– General linear mixed effects models
– Fixed effects: treatment and year
– Random effects: site and block
Conventional Drill
Minimum-till Drill
Year 1 (Mt. Home site)
Year 1 (Mt. Home Site)
Year 2 (Saylor Creek site)
Year 2 (Saylor Creek site)
Wyoming Big Sagebrush & Sandberg Bluegrass
Wyoming Big Sagebrush & Sandberg Bluegrass
Wyoming Big Sagebrush & Sandberg Bluegrass
Conventional Drill
Minimum-till Drill
Drill-broadcast
Drill-broadcast
R5X
No Seed
Photos from Scooby Site, 2nd Year
No Seed
Conclusions
• Drilled Species (Large Seeds) Establishment
Seeded > Non-seeded
Minimum-till = Conventional
• Broadcast Species (Small Seeds) Establishment
Seeded >= Non-seeded
Drill-broadcast >= Aerial Broadcast
Drill-broadcast: Minimum-till >= Conventional
Fall Aerial >= Winter Aerial
• Conventional drill had greater impact on
residual Sandberg bluegrass
Acknowledgements
Funding
• Joint Fire Science Program
• Great Basin Native Plant Program
• National Fire Plan
• Bureau of Land Management
Collaborators and Assistants
• US Forest Service RMRS: Scott Jensen, Matt Fisk, Erin Denney,
Alexis Malcomb, Jan Gurr, Robin Bjork
• Natural Resources Conservation Service: Loren St. John,
Boyd Simonson, Charlie Bair, Brent Cornforth
• US Air Force: Carl Rudeen
• Bureau of Land Management: Mike Barnes,
Gary Kidd, Jeff Rose
• Truax Co. Inc.: Jim Truax
Questions…
Treatment * Year n.s.
Year 1>Year2
Treatment * Year n.s.
Year 1<Year2
Treatment * Year n.s.
Year 1<Year2
Seeding Treatments
(applied to 70 m × 30 m plots)
Drill Type
Drill
Seed Mix
Broadcast
Seed Mix
Broadcast
Timing
No drill, No seed
No seed
Conventional
Drilled in
drill
alternate rows
in fall
Drill-broadcast in
alternate rows
Aerial (hand)
broadcast
Fall
Fall
Winter
No seed
Minimum-till
Drilled in
drill
alternate rows
in fall
Drill-broadcast in
alternate rows
Aerial (hand)
broadcast
Fall
Fall
Winter
Monthly and long-term precipitation for Northern Great Basin postfire seedings.
= planting date, m.d. = missing data.
Site Differences
Relative Elevation
Post-treatment
Precipitation
Drilled Species
Broadcast Species
Glass
Butte
High
Mountain
Home
Low
Saylor
Creek
Mid
Low
Low
High
High
Low
Low
High
High
High*
Low
High*
Low
*including residual plants
Glass Butte
Mountain Home
Saylor Creek
Scooby
General views of sites, second year post-treatment
Scooby
High
Wyoming big sagebrush, 2nd year
Minimum Drill 10X Broadcast (Scooby)
Rangeland Drill + Fall Broadcast
(Saylor Ck.)
Glass Butte
Western Yarrow in Minimum-till Drill Broadcast Treatment
(Saylor Creek, 2nd Year)
Wyoming Big Sagebrush Shrub-steppe Vegetation
• Artemisia tridentata ssp.
wyomingensis + other
shrubs, perennial grasses
and forbs
• Widespread in lower
elevations of northern
Great Basin region
• Impacted by overgrazing,
fire and invasive weeds