Changes in stand structure and composition after thinning and burning in low-elevation, dry ponderosa pine and Douglas-fir forests of northeastern Oregon
Hauser, A. Scott, comp. 2008. Changes in stand structure and composition after thinning and burning in low-elevation, dry ponderosa pine and Douglas-fir forests of northeastern Oregon. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available:https://research.fs.usda.gov/feis/fire-studies/youngblood-et-al-2008
Sources
Unless otherwise indicated, the information in this Research Project Summary comes from the following papers:
- Metlen, Kerry L.; Fiedler, Carl E.; Youngblood, Andrew. 2004. Understory response to fuel reduction treatments in the Blue Mountains of northeastern Oregon. Northwest Science. 78(3): 175-185 [5].
- Youngblood, Andrew; Metlen, Kerry L.; Coe, Kent. 2006. Changes in stand structure and composition after restoration treatments in low elevation dry forests of northeastern Oregon. Forest Ecology and Management. 234(1-3): 143-163 [6].
Species Included in the Summary
Common names are used throughout this summary. For the list of the common and scientific names of species discussed in this summary see Table A1.
Study Location
The study was conducted in the northern Blue Mountains (lat 45°40'N, long 117°13'W), 45 km north of Enterprise, Oregon [5].
Site Description
The study area includes almost 9,400 ha of plateaus, benches, and deeply incised drainages formed in highly fractured, ancient Columbia River basalt. Soil textures are fine to coarse loams, in some cases with high ash content. The climate is strongly continental. Weather data from Enterprise, Oregon, 100 to 400 m below the study area, indicate annual precipitation averaging 500 mm and a mean annual temperature of 7.4 °C. Frost may occur at anytime of year. The Enterprise weather station may be in a rain shadow that receives less precipitation than the study area [6].
| Unit | Treatment | Size (ha) | Elevation (m) | Aspect (°) | Slope (%) | Heat load index¹ | Plant community |
|---|---|---|---|---|---|---|---|
| 6A | Thin | 14.4 | 1,361 | 283 | 11 | 0.9078 | Rocky Mountain Douglas-fir/pinegrass |
| 7 | Thin | 11.9 | 1,305 | 292 | 21 | 0.8952 | Rocky Mountain Douglas-fir/common snowberry |
| 9 | Thin | 9.1 | 1,235 | 51 | 12 | 0.8258 | Columbia ponderosa pine/bluebunch wheatgrass |
| 22 | Thin | 8.8 | 1,380 | 286 | 8 | 0.9049 | Rocky Mountain Douglas-fir/white spirea |
| 8B | Burn | 10.1 | 1,170 | 82 | 8 | 0.8645 | Columbia ponderosa pine/Idaho fescue |
| 10B | Burn | 8.4 | 1,920 | 50 | 8 | 0.8733 | Columbia ponderosa pine/Idaho fescue |
| 21 | Burn | 10.4 | 1,373 | 230 | 18 | 0.9503 | Rocky Mountain Douglas-fir/pinegrass |
| 24 | Burn | 8.4 | 1,260 | 84 | 9 | 0.8579 | Columbia ponderosa pine/Idaho fescue |
| 6B | Thin + burn | 12.1 | 1,388 | 221 | 15 | 0.9219 | Rocky Mountain Douglas-fir/pinegrass |
| 8A | Thin + burn | 10.4 | 1,174 | 297 | 9 | 0.8955 | Columbia ponderosa pine/Idaho fescue |
| 10A | Thin + burn | 15.9 | 1,186 | 297 | 13 | 0.8903 | Columbia ponderosa pine/Idaho fescue |
| 1112 | Thin + burn | 11 | 1,185 | 274 | 9 | 0.9136 | Columbia ponderosa pine/Idaho fescue |
| 245 | Control | 13.8 | 1,286 | 218 | 11 | 0.8928 | Columbia ponderosa pine/common snowberry |
| 15 | Control | 15.1 | 1,113 | 108 | 18 | 0.8257 | Rocky Mountain Douglas-fir/pinegrass |
| 18 | Control | 7.5 | 1,333 | 296 | 26 | 0.8822 | Rocky Mountain Douglas-fir/pinegrass |
| 23 | Control | 12 | 1,379 | 345 | 10 | 0.8714 | Rocky Mountain Douglas-fir/pinegrass |
| ¹Heat load index based on aspect, slope, and latitude, with 1.0 being the warmest slope (southwest-facing). | |||||||
Plant Community
The study area is a mosaic of low-elevation (1,040-1,480 m), dry Columbia ponderosa pine and Rocky Mountain Douglas-fir forests. Warm, dry sites on gentle south-facing slopes are typified by Columbia ponderosa pine and open, low shrub- and grass-dominated communities. North-facing plateau slopes, draws, and swales with relatively deep soils are dominated by Rocky Mountain Douglas-fir and Columbia ponderosa pine [6].
Most of the area is in a stem exclusion, closed-canopy stage. Most stands are dominated by 70- to 100-year-old, even-aged Columbia ponderosa pines, with smaller Rocky Mountain Douglas-firs that have regenerated after extensive partial cutting. Within this mosaic are scattered large trees and remnants of old, unharvested stands. The study area historically had endemic levels of bark beetles. During the 1990s, the area was affected by increased levels of bark beetles, especially western pine beetle (Dendroctonus brevicomis) and eastern pine engraver (Ips pini) [6]. Grazing is a traditional land use in the study area and occurs on all treatment sites [5]. Indicator species analysis identified species differentially associated with treatment sites [6].
| Species (life form)¹ | Indicator value² (P) | Percent frequency (and cover) on pretreatment sites | |||
|---|---|---|---|---|---|
| Thin | Burn | Thin + burn | Control | ||
| common snowberry (s) | 45.7 (0.001) | 83 (6.0) | 61 (1.8) | 78 (1.6) | 52 (2.3) |
| heartleaf arnica (f) | 38.7 (0.001) | 77 (8.4) | 60 (2.5) | 70 (4.2) | 58 (2.2) |
| white spirea (s) | 33.0 (0.001) | 63 (3.9) | 27 (1.7) | 44 (2.1) | 27 (2.1) |
| Idaho fescue (g) | 39.9 (0.001) | 36 (5.8) | 80 (15.8) | 74 (12.2) | 45 (5.4) |
| prairie Junegrass (g) | 37.5 (0.001) | 5 (0.3) | 46 (2.2) | 1 (3.0) | 21 (0.8) |
| blue wildrye (g) | 20.9 (0.001) | 6 (0.3) | 31 (3.3) | 0 (0) | 21 (2.0) |
| bluebunch wheatgrass (g) | 15.6 (0.014) | 6 (2.0) | 32 (4.2) | 32 (4.4) | 4 (0.9) |
| California brome (g) | 10.3 (0.001) | 0 (0) | 10 (6.5) | 0 (0) | 0 (0) |
| Geyer's sedge (g) | 25.5 (0.003) | 65 (5.7) | 14 (3.3) | 30 (5.3) | 60 (4.2) |
| western needlegrass (g) | 16.9 (0.001) | 19 (2.6) | 9 (1.3) | 0 (0) | 22 (3.2) |
| western fescue (g) | 15.3 (0.001) | 0 (0) | 1 (0.3) | 0 (0) | 12 (2.6) |
| purple oniongrass (g) | 10.3 (0.001) | 0 (0) | 0 (0) | 0 (0) | 8 (4.1) |
| ¹ f=forb, g=graminoid, s=shrub. ² Indicator value=relative abundance (i.e., relative density) × relative frequency [1,6]. | |||||
Plant Phenology
Phenology of vegetation was not described. Pretreatment measurements were made prior to the summer 1998 thinning treatments. Vegetation measurements in the first postfire year were taken in early summer [5].
Fire Description
The research project aimed to promote forest sustainability by reducing potential for tree mortality due to mountain pine beetles and crown fire. Treatments were designed to favor Columbia ponderosa pine over Rocky Mountain Douglas-fir and to reduce tree basal area.
The researchers implemented 4 treatments with 4 replications of each: thin, burn, thin-burn, and control (no active management). Thinning occurred in summer 1998, and burning was conducted in mid-September 2000. The management goal was to modify stand structure such that mortality from bark beetles was reduced and 80% of the dominant and codominant trees could survive a wildfire occurring under 80th percentile weather conditions. To meet this goal, treatments aimed to reduce total basal area from about 26 m²/ha to about 16 m²/ha. In the thin treatment, all live trees ≥53 cm DBH, which represented late-successional and old stands, were left uncut; conifers within 9 m of dominant Columbia ponderosa pines were removed. The burn treatments aimed to reduce the basal area of Columbia ponderosa pines ≥51 cm DBH by <20%, with similarly sized Rocky Mountain Douglas-firs reduced by ≤30%. For trees ranging from 20 to 51 cm DBH, the burn treatments were designed to kill <30% of Columbia ponderosa pines and 40% of Rocky Mountain Douglas-firs. Targets for the thin-burn treatment were the same as for the thin-only and burn-only treatments; fire behavior was also managed to reduce accumulations of cured tree branches and tops left by thinning [6].
Burns were conducted as both backing and strip head fires under conditions suitable for low flame heights. All burns were "fairly complete," low-intensity fires that consumed 75% of the grasses and exposed <25% of mineral soil [5].
| Treatment | Burn | Thin + burn | ||||||
|---|---|---|---|---|---|---|---|---|
| Unit | 8B | 10B | 21 | 24 | 6B | 8A | 10A | 1112 |
| Ambient temperature (°C) | 20-24 | 20-24 | 12-23 | 13-21 | 12-21 | 20-24 | 20-24 | 12-23 |
| Relative humidity (%) | 33-48 | 33-48 | 23-50 | 25-49 | 24-76 | 33-48 | 33-48 | 23-50 |
| Wind speed (m/s) | 2.2 | 2.2 | 0.8-2.8 | 0.8-2.2 | 0.8-3.6 | 2.2 | 2.2 | 0.8-2.8 |
| 10-h fuel moisture (%)¹ | 13.7 (0.3) | 12.8 (0.7) | 15.0 (1.1) | 12.2 (1.1) | 12.9 (0.7) | 17.8 (1.1) | 17.6 (1.7) | 16.4 (2.4) |
| 1,000-h fuel moisture (%)² | 63.0 (6.2) | 40.9 (7.2) | 55.9 (8.1) | 48.6 (7.0) | 28.6 (2.7) | 45.5 (3.4) | 31.2 (4.0) | 37.7 (4.5) |
| Mean flame length (m) | 0.9 | 0.9 | 0.6 | 0.5 | 0.9 | 0.9 | 0.9 | 0.9 |
| ¹Fuel moisture in dead fuels 0.6 to 2.5 cm in diameter. Data are means (SE) from 5 samples. ²Fuel moisture in dead fuels 7.6 to 20.3 cm in diameter. Data are means (SE) from 21 to 31 samples. | ||||||||
Fire Season/Severity Classification
Late summer/low
Fire Effects on Plant Community
Thinning, burning, and thinning followed by burning all modified forest structure and composition, but none reduced overstory canopy cover significantly. Only the thin-and-burn treatments reduced tree basal area to the level desired to meet management objectives. All active treatments reduced downed log density. Understory composition was little affected by treatments.
Treatment Effects on Trees
On control sites, live basal area, live tree density, and seedling density tended to increase during the study. Thinning alone reduced overstory tree density but did not reduce overstory canopy cover and probably did not reduce susceptibility to crown fire. Burning alone reduced small trees, mainly Douglas-firs, but had little effect on the overstory. The thin-and-burn treatment reduced live basal area and live tree density more than thinning or burning alone, and produced the lowest seedling densities of all treatments [6].
| Treatment | 1998 (before treatment) | 2004 (6 years after thinning, 4 years after burning) | ||||
|---|---|---|---|---|---|---|
| Live tree basal area (m²/ha) | Live tree density (stems/ha) | Seedling density (stems/ha) | Live tree basal area (m²/ha) | Live tree density (stems/ha) | Seedling density (stems/ha) | |
| Thin | 27.3 (2.4) | 698 (109) | — | 19.6 (0.2) | 452 (72) | 966 (252) |
| Burn | 19.2 (2.3) | 286 (32) | — | 19.5 (2.4) | 247 (24) | 27 (12) |
| Thin + burn | 20.1 (1.1) | 398 (100) | — | 16.0 (1.0) | 144 (15) | 16 (6) |
| Control | 27.4 (4.7) | 469 (33) | — | 28.4 (3.0) | 597 (17) | 1,595 (612) |
Basal area of dead snags did not differ significantly among treatments, including controls. Mean basal area of snags was 2.8 m²/ha in 1998 (88% Columbia ponderosa pine) and 2.6 m²/ha in 2004 (58% Columbia ponderosa pine). Snag density averaged 46 stems/ha in 1998 and 53 stems/ha in 2004. Burn treatments, with or without thinning, tended to increase snag density relative to other treatments; thinning tended to reduce snags.
Treatment Effects on Coarse Woody Debris
All active treatments reduced downed log density relative to that on control sites (P=0.011). Log density was significantly less on burned sites than on thinned sites (P=0.003) and tended to be less on thinned-and-burned sites than on thinned-only sites. Length, volume, and cover of coarse woody debris did not differ significantly among treatments [6].
| Treatment | Density (stems/ha) | Cumulative length (m/ha) | Volume (m³/ha) | Cover (m²/ha) |
|---|---|---|---|---|
| Thin | 156 (37) | 156.2 (30.0) | 6.5 (1.0) | 2.2 (0.2) |
| Burn | 30 (5) | 43.9 (11.4) | 2.2 (0.5) | 1.4 (0.2) |
| Thin + burn | 61 (8) | 80.2 (26.1) | 2.3 (0.6) | 1.4 (0.2) |
| Control | 195 (22) | 210.0 (53.0) | 9.2 (1.8) | 2.6 (0.3) |
Treatment Effects on Understory Vegetation
Total understory cover in the first postfire year was 95.7% on control sites, greater than on thinned-only sites (60.7%) and significantly greater than on burned-only sites (50.5%) or thinned-and-burned sites (42.3%). Species richness on burned sites (with and without thinning) did not differ significantly from that on control sites, but species richness on thinned-only sites was significantly less than on control sites. Cover of forbs was less on thinned than control plots in the first postfire year, perhaps due in part to increased slash on the ground. All active treatments had lower cover of Geyer's sedge than control sites, but the difference was significant only on thinned sites. Prairie Junegrass cover was significantly greater on thinned-and-burned sites than on thinned-only or control sites [5]. The frequency and cover of understory species differed among treatment sites in 1998, before any treatments [6], so differences may not be attributable to treatments alone.
Understory species diversity did not change significantly in any treatment from 1998 to 2004. On thinned sites, the authors note that understory species composition was "remarkably stable and consistent" before and after treatment. Indicator species for thinning units in 1998, before thinning, were also indicators for thinned units in 2004, with similar cover and frequency. Eight nonnative species were found on thinned sites in 2004; the only one with more than trace cover was cheatgrass. On burned-only sites, several perennial species increased in frequency and cover from 1998 to 2004. These included heartleaf arnica, pinegrass, Geyer's sedge, white spirea, and common snowberry. Cover of Idaho fescue decreased. The number of nonnative species on burned-only sites increased, but only 2 of these species (cheatgrass and Japanese brome) had more than "limited" cover in 2004. On thinned-and-burned sites, as on burn-only sites, bluebunch wheatgrass, Geyer's sedge, white spirea, and common snowberry increased, while Idaho fescue decreased. Number of nonnative species increased from 2 to approximately 9. As in other treatments, cheatgrass was the most abundant nonnative species. Forty-nine indicator species were used to characterize the plant communities sampled, based on presence with more than trace cover in most treatments [6].
| Species (life form)¹ | Indicator value² (P) | Percent frequency (and cover) on treatment sites | |||
|---|---|---|---|---|---|
| Thin | Burn | Thin + burn | Control | ||
| common snowberry (s) | 38.6 (0.001) | 89 (10.5) | 87 (3.5) | 91 (3.8) | 83 (6.9) |
| white spirea (s) | 34.7 (0.001) | 68 (6.8) | 28 (2.6) | 43 (5.4) | 56 (2.4) |
| pinegrass (g) | 33.7 (0.001) | 91 (29.1) | 81 (23.1) | 75 (21.6) | 81 (12.4) |
| heartleaf arnica (f) | 29.2 (0.018) | 86 (9.7) | 74 (10.9) | 63 (3.6) | 81 (7.3) |
| houndstongue hawkweed (f) | 26.7 (0.008) | 77 (0.6) | 74 (0.5) | 66 (0.5) | 55 (0.3) |
| Virginia strawberry (f) | 26.4 (0.029) | 70 (2.5) | 63 (1.4) | 56 (1.0) | 72 (1.9) |
| paintbrush (f) | 19.5 (0.001) | 51 (0.4) | 24 (0.4) | 48 (0.4) | 12 (0.3) |
| wormleaf stonecrop (f) | 19.1 (0.011) | 28 (3.8) | 30 (1.2) | 23 (0.3) | 31 (0.3) |
| western showy aster (f) | 14.2 (0.003) | 21 (1.2) | 1 (0.3) | 4 (2.0) | 12 (0.3) |
| prairie Junegrass (g) | 35.0 (0.001) | 40 (1.7) | 87 (1.5) | 77 (1.2) | 41 (0.7) |
| Idaho fescue (g) | 34.1 (0.001) | 73 (5.2) | 93 (9.5) | 81 (9.4) | 71 (5.3) |
| common yarrow (f) | 32.0 (0.031) | 88 (2.1) | 98 (1.8) | 88 (1.0) | 91 (0.9) |
| tiny trumpet (f) | 24.5 (0.001) | 23 (0.4) | 63 (0.4) | 65 (0.3) | 40 (0.3) |
| miner's-lettuce (f) | 20.2 (0.001) | 10 (0.4) | 33 (0.7) | 8 (0.3) | 27 (0.3) |
| bluebunch wheatgrass (g) | 17.6 (0.017) | 25 (2.6) | 47 (4.0) | 39 (5.5) | 12 (3.2) |
| onespike danthonia (g) | 16.8 (0.001) | 6 (4.7) | 28 (5.5) | 25 (1.3) | 5 (8.2) |
| sticky phlox (f) | 15.9 (0.011) | 14 (3.7) | 33 (1.9) | 26 (0.5) | 14 (0.4) |
| desertparsley (f) | 14.1 (0.001) | 16 (0.3) | 31 (0.4) | 29 (0.3) | 8 (0.3) |
| stickywilly (f) | 14.1 (0.002) | 7 (0.5) | 31 (0.5) | 2 (0.3) | 24 (0.6) |
| chaparral willowherb (f) | 33.7 (0.001) | 24 (0.3) | 39 (0.4) | 74 (0.4) | 31 (0.6) |
| tailcup lupine (f) | 33.5 (0.001) | 75 (2.2) | 56 (1.0) | 77 (3.1) | 63 (1.5) |
| Rocky Mountain goldenrod (f) | 28.1 (0.001) | 18 (2.2) | 35 (1.4) | 64 (1.1) | 6 (0.8) |
| western stoneseed ( f) | 25.3 (0.001) | 44 (0.4) | 43 (0.4) | 62 (0.4) | 15 (0.3) |
| arrowleaf balsamroot (f) | 24.8 (0.003) | 47 (1.8) | 42 (2.2) | 46 (4.7) | 18 (0.7) |
| cheatgrass (g) | 24.6 (0.006) | 28 (3.7) | 51 (2.9) | 55 (3.8) | 18 (0.9) |
| Douglas' knotweed (f) | 23.7 (0.001) | 24 (0.3) | 30 (0.4) | 45 (0.7) | 27 (0.4) |
| pinkfairies (f) | 23.0 (0.001) | 12 (0.3) | 25 (0.4) | 44 (0.3) | 5 (0.3) |
| meadow deathcamas (f) | 17.2 (0.010) | 38 (0.3) | 43 (0.3) | 51 (0.3) | 21 (0.3) |
| neckweed (f) | 15.7 (0.001) | 2 (0.3) | 14 (0.3) | 29 (0.4) | 5 (0.7) |
| Japanese brome (g) | 15.1 (0.027) | 11 (0.5) | 30 (2.4) | 38 (1.5) | 21 (0.7) |
| North Africa grass (g) | 12.8 (0.002) | 1 (0.3) | 18 (1.8) | 25 (1.3) | 0 (0) |
| prickly lettuce (f) | 12.3 (0.001) | 4 (0.3) | 8 (0.3) | 20 (0.3) | 1 (0.3) |
| sagebrush mariposa lily (f) | 11.1 (0.002) | 12 (0.3) | 16 (0.3) | 25 (0.3) | 4 (0.3) |
| narrowleaf pussytoes (f) | 10.8 (0.001) | 0 (0) | 5 (0.3) | 15 (0.3) | 3 (0.3) |
| woods strawberry (f) | 41.0 (0.001) | 34 (3.2) | 28 (2.2) | 7 (1.3) | 74 (3.0) |
| longstalk clover (f) | 31.4 (0.001) | 34 (12.3) | 55 (11.6) | 6 (3.1) | 81 (8.5) |
| Geyer's sedge (g) | 29.9 (0.002) | 66 (11.1) | 59 (11.1) | 57 (8.3) | 81 (13.6) |
| sweetcicely (f) | 26.4 (0.001) | 3 (0.3) | 1 (0.3) | 3 (0.3) | 32 (0.3) |
| largeleaf sandwort (f) | 25.7 (0.001) | 9 (1.1) | 5 (1.1) | 4 (0.3) | 36 (1.1) |
| rose (s) | 25.3 (0.009) | 68 (1.2) | 54 (1.1) | 39 (0.5) | 68 (1.4) |
| sticky cinquefoil (f) | 19.0 (0.048) | 26 (1.2) | 33 (0.5) | 27 (0.4) | 55 (0.5) |
| Saskatoon serviceberry (s) | 19.7 (0.001) | 26 (0.4) | 21 (0.3) | 1 (0.3) | 36 (0.6) |
| smallflower miterwort (f) | 18.1 (0.001) | 2 (0.3) | 2 (0.3) | 0 (0) | 19 (1.0) |
| largeleaf avens (f) | 16.3 (0.001) | 1 (0.3) | 0 (0) | 1 (0.3) | 17 (0.8) |
| purple oniongrass (g) | 15.4 (0.001) | 0 (0) | 0 (0) | 0 (0) | 15 (0.8) |
| western needlegrass (g) | 15.2 (0.011) | 32 (1.0) | 13 (1.3) | 5 (0.4) | 42 (0.7) |
| common selfheal (f) | 14.9 (0.001) | 4 (0.3) | 0 (0) | 2 (0.7) | 17 (1.3) |
| common dandelion (f) | 12.4 (0.014) | 21 (0.3) | 18 (0.3) | 15 (0.3) | 33 (0.3) |
| field pussytoes (f) | 11.9 (0.001) | 11 (0.3) | 0 (0) | 5 (0.3) | 14 (1.8) |
| ¹ f=forb, g=graminoid, s=shrub. ² Indicator value=relative abundance × relative frequency [6]. Relative abundance=relative density [1]. | |||||
The thin treatments and burn treatments opened stands to some extent and altered tree species composition, but they did not reduce basal area to the target level for increasing resistance to crown fire and bark beetle attack (16 m²/ha). The thin-and-burn treatment did achieve this management objective [6].
Activity fuels from thinning caused variable fire spread in thinned-burned stands because activity fuels occurred in relatively uniform, parallel strips that had higher fuel moisture than areas outside these strips [6].
Treatments caused minor changes in understory vegetation, indicating that "the majority of understory species have adapted to the same disturbance regimes" that the treatments aimed to mimic [6].
The authors suggest that repeated treatments are needed in 10 to 15 years to bring stand structure and composition more in line with historical conditions. They comment that one set of treatments is not likely to mitigate nearly 80 years of fire exclusion and fuel accumulation in low-elevation, dry forests [6].
| Biophysical Setting | Mean Fire Interval (years) | Fire Severity Percent (%) | ||||||
|---|---|---|---|---|---|---|---|---|
| Code | Fire Regime Group | Low | Mixed | Replacement | All | Low | Mixed | Replacement |
| Series 10532 - Northern Rocky Mountain Ponderosa Pine Woodland and Savanna - Xeric | ||||||||
| 10532_7_9 | III-A | 136 | 100 | 258 | 47 | 35 | 47 | 18 |
| Series 11660 - Middle Rocky Mountain Montane Douglas-fir Forest and Woodland | ||||||||
| 11660_9_10_19 | I-C | 106 | 54 | 112 | 27 | 26 | 50 | 24 |
| Summary | ||||||||
| Minimum | 106 | 54 | 112 | 27 | 26 | 47 | 18 | |
| Maximum | 136 | 100 | 258 | 47 | 35 | 50 | 24 | |
| Mean | 121 | 77 | 185 | 37 | 31 | 49 | 21 | |
| Median | 121 | 77 | 185 | 37 | 31 | 49 | 21 | |
| Percentage of fires in 3 fire severity classes, derived from LANDFIRE succession modeling. Replacement-severity fires cause >75% kill or top-kill of the upper canopy layer; mixed-severity fires cause 26%-75%; low-severity fires cause <26%. | ||||||||
| LANDFIRE. 2020. Biophysical settings models and descriptions, [Online]. Washington, DC: U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior; U.S. Geological Survey; Arlington, VA: The Nature Conservancy, (Producers). Available: https://www.landfirereview.org/search.php [96496] | ||||||||
| Common name | Scientific name |
|---|---|
| Forbs | |
| common yarrow | Achillea millefolium |
| field pussytoes | Antennaria neglecta |
| narrowleaf pussytoes | Antennaria stenophylla |
| heartleaf arnica | Arnica cordifolia |
| arrowleaf balsamroot | Balsamorhiza sagittata |
| sagebrush mariposa lily | Calochortus macrocarpus |
| paintbrush | Castilleja spp. |
| pinkfairies | Clarkia pulchella |
| miner's-lettuce | Claytonia perfoliata |
| tiny trumpet | Collomia linearis |
| chaparral willowherb | Epilobium minutum |
| western showy aster | Eurybia conspicua |
| woods strawberry | Fragaria vesca |
| Virginia strawberry | Fragaria virginiana |
| stickywilly | Galium aparine |
| largeleaf avens | Geum macrophyllum |
| houndstongue hawkweed | Hieracium cynoglossoides |
| prickly lettuce | Lactuca serriola |
| western stoneseed | Lithospermum ruderale |
| desertparsley | Lomatium spp. |
| tailcup lupine | Lupinus caudatus |
| smallflower miterwort | Mitella stauropetala |
| largeleaf sandwort | Moehringia macrophylla (Arenaria macrophylla)* |
| sweetcicely | Osmorhiza berteroi |
| sticky phlox | Phlox viscida |
| Douglas' knotweed | Polygonum douglasii |
| sticky cinquefoil | Potentilla glandulosa |
| common selfheal | Prunella vulgaris |
| wormleaf stonecrop | Sedum stenopetalum |
| Rocky Mountain goldenrod | Solidago multiradiata |
| common dandelion | Taraxacum officinale |
| longstalk clover | Trifolium longipes |
| neckweed | Veronica peregrina |
| meadow deathcamas | Zigadenus venenosus |
| Graminoids | |
| western needlegrass | Achnatherum occidentale |
| California brome | Bromus carinatus var. carinatus |
| Japanese brome | Bromus japonicus |
| cheatgrass | Bromus tectorum |
| pinegrass | Calamagrostis rubescens |
| Geyer's sedge | Carex geyeri |
| onespike danthonia | Danthonia unispicata |
| blue wildrye | Elymus glaucus |
| Idaho fescue | Festuca idahoensis |
| western fescue | Festuca occidentalis |
| prairie Junegrass | Koeleria macrantha |
| purple oniongrass | Melica spectabilis |
| bluebunch wheatgrass | Pseudoroegneria spicata (Pseudoroegneria spicatum)* |
| North Africa grass | Ventenata dubia |
| Shrubs | |
| Saskatoon serviceberry | Amelanchier alnifolia |
| rose | Rosa spp. |
| white spirea | Spiraea betulifolia |
| common snowberry | Symphoricarpos albus |
| Trees | |
| Columbia ponderosa pine | Pinus ponderosa var. ponderosa |
| Rocky Mountain Douglas-fir | Pseudotsuga menziesii var. glauca |
| *For species that have undergone scientific name changes, names in parentheses are those used in the research papers. | |
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