Fire in Juniper Invaded Sagebrush Steppe

Woodland Phases PHASE 1 PHASE 2 PHASE 3 PHASE 3 Vegetation change Fuel load changes in ARTRV Phase 1; 5.4 tons Phase 2; 10.6 tons Phase 3; 18.6 tons Plant Community Characteristics PHASE 3 PHASE 3

Cut-and-leave

Partial cut and broadcast burn

Burning effects Soil Temp Mortality of plant roots and seeds can occur between 120o and 200o F Soil microbial death can occur at temperatures as low as 120o to 250o F 1-h fuels are juniper wood less than ¼ inch in diameter 10-h fuels are juniper wood, 1/4–1.0 inches in diameter 100-h fuels are juniper wood, 1.0–3.0 in in diameter 1000-h fuels are juniper wood, 3.0-8.0 inches in diameter Consumption of woody fuels > 10-hr fuel class = killing perennial herbs

Fuel Reduction Treatments Broadcast Pile – Burn Jackpot Winter , Nov-March Growing Season; Oct, April Plant Association Mechanical Disturbance Time of Burn Fuel Consumption

Fire Effects Sept broadcast Burn; 100–1000 h Beneath cut trees Surface soil temp.; 1300–1750 o F 1 inch deep soil temp; 231–580 o F Canopy litter mats 350–1300 o F Interspace/woodland floor 170–400 Plot area burned (%); 95–100 January Jackpot Burn; 1-h Surface soil and 1 inch deep temp.; Not detected Plot area burned (%); 12–22 April Jackpot Burn; 10–1000 h Surface soil temp.; 1200–1700 o F 1 inch deep soil temp; 350–580 o F Plot area burned (%); 20–28

Time of Burn Winter Burn (Nov-March) Fall or Late Spring Burn (Sept-Oct), (April-May)

Broadcast fire

Bunchgrass mortality Fall Broadcast Burns Phase 1; 10 – 15% decrease Winter Jackpot Burns Phase 1; none Phase 2; none to <5% Phase 3; <10%

Phase II Phase III Natives dominate cheatgrass dominate In all communities understory cover was double that of pre-treatment conditions the third growing season after fire. The reduction of surface litter, however, has resulted in increased bareground and on steeper slopes runoff and erosion has occurred on all sites. Most sites will stabilize hydrologically in the next few years. Areas that remain dominated by cheatgrass won’t stabilize hydrologically Response was highly variable – Response can be ranked by herbaceous recovery, weed threats, and potential for recover despite early weed dominance, and woodland invasive phase Needlegrass/bluebunch sites had the worst response – primarily an annual affair On the other end of the spectrum the north fescue type has had the best overall response with mostly native perennials dominating. Needlegrass; This community had a poor understory component prior to treatment and woodlands were all phase III. The fire eliminated many of the remaining bunchgrasses, which was not a lot to begin with. These sites are dominated by cheatgrass (50-80% of herbaceous composition) and annual forbs. Reseeding these areas should be considered in the future. Cutting combined with winter burning may also be a better option for areas. North Fescue; Composition of the understory has largely been dominated by perennial grasses and forbs, and annual forbs (especially 2005). These sites have recovered the fastest in terms of maintaining native composition. There is little threat of weeds competing in this type. Other plant communities have varied from annual to perennial dominance in the understory. Aspen; Aspen sprouting has varied from 2000 to 4500 stems acre-1 in treated stands. Sprouting is expected to continue as open areas fill in with new recruits. Browsing by ungulates has been minimal and will likely not impede aspen regeneration. The understory response varied from stands dominated by non-natives (mullein and/or cheatgrass) or perennial grasses and forbs. Given potentials for the community it seems unlikely that the presence of mullein or cheatgrass will be maintained. Perennial grass density – seems key recovery point Phase III cheatgrass dominate

Woodland Phase, Steens Mt, Oregon Bunchgrass Density Woodland Phase, Steens Mt, Oregon Burned

Woodland Phase, Steens Mt, Oregon Cheatgrass Cover Woodland Phase, Steens Mt, Oregon Burned

Perennial Grass Seedling Density Artrva/Stle-Feid

Post-Fire Vegetation Response Association Yr Phase 1 & 2 Woodlands Phase 3 Woodlands High Intensity Low Intensity Fire Fire Artrva/Feid Artrva/Stle Artrva/Stco/Feid Cele/Artrva/Stoc Artrtr/Pssp-Stth Artrwy/Pssp-Stth Arar/Feid Potr/Syor/Agtr-Feid 15 8 5 20 4 10 6 Native grass-forb Brte-Native grass Brte Brte & Broadleaf Grass-forb Grass-forb/Brte

UNSEEDED SEEDED

Broadcast fire Woody cover > 30% consider re-seeding Phase 3 woodlands – re-seed always Warm, dry sites – reseed with introduced bunchgrasses Cooler, higher precip sites – native reseeding How many do you cut? No more than 25% or ¼ of the trees. For fall burning, about one-quarter to one-third of the trees need to be cut to carry fire through juniper communities with 40-70% canopy cover. Cutting more than 25% is therefore excessive. The partial cut and burn treatments were all successful at removing remaining live western juniper trees. On the SNOWBERRY the fire killed 95-99% of remaining live trees and juniper cover was reduced by 99%. On the SAGE the fires killed 85-100% of the remaining live trees and juniper cover was reduced by 90-100%. Crown fires can be generated so perhaps cutting strips might work rather than selective cutting throughout the stand Impacts of the treatments were severe to the understory. Perennial grass density cut by a 70-80%. Early successional composition were not different than described in earlier model developed for Pinyon-Juniper by folks out of Utah and Nevada. Dominated by annual and perennial forbs. There was no statistical difference in understory recovery among the cutting-fire treatments within community type. Indications that the fewer trees cut understory appears to be in better shape. Cheatgrass presence is low though has the potential to increase in sagebrush-needlegrass community type when perennial grasses are lacking. To speed recovery, seeding of native or non-native grasses is recommended. Seeding forbs appears unnecessary as forb response on these sites is already substantial. Without seeding will require a longer period of grazing rest and deferrals to permit recovery of perennial vegetation. It is critical to manage grazing such that grass seed production and recruitment are enhanced in the first 3-5 years post-fire for these type of communities