Response of vegetation to prescribed burning in a Jeffrey pine-California black oak woodland and a deergrass meadow at Cuyamaca State Park, California
Fryer, Janet L., comp. 2007. Response of vegetation to prescribed burning in a Jeffrey pine-California black oak woodland and a deergrass meadow at Cuyamaca Rancho State Park, California. 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/martin-2007
Sources
Unless otherwise indicated, the information in this Research Project Summary comes from the following papers:
- Lathrop, Earl W.; Martin, Bradford D. 1982. Response of understory vegetation to prescribed burning in yellow pine forests of Cuyamaca Rancho State Park, California. Aliso. 10(2): 329-343 [1].
- Martin, Bradford D. 1981. Vegetation responses to prescribed burning in a mixed-conifer woodland, Cuyamaca Rancho State Park, California. Loma Linda, CA: Loma Linda University. 112 p. Thesis [2].
- Martin, Bradford D. 1982. Vegetation responses to prescribed burning in Cuyamaca Rancho State Park, California. In: Conrad, C. Eugene; Oechel, Walter C., technical coordinators. Proceedings of the symposium on dynamics and management of Mediterranean-type ecosystems; 1981 June 22-26; San Diego, CA. Gen. Tech. Rep. PSW-58. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 617 [3].
Species Included in This Summary
See Table A1.
Study Location
The study sites were in Cuyamaca Rancho State Park in eastern San Diego County, California. Burning was conducted on the West Mesa and East Mesa areas of the park [1,3]. There were 5 burn sites: 1 on West Mesa at Paso Picacho, 2 on East Mesa at Granite Springs, and 2 on East Mesa at Oakzanita [2].
Site Description
Elevations at the burn sites were: 1,493 m at Paso Picacho, 1,515 m at Granite Springs, and 1,478 m at Oakzanita. Other site information was not provided.
Plant Community
The Paso Picacho site was a mixed-conifer Jeffrey pine-California black oak (Pinus jeffreyi-Quercus kelloggii) woodland with a chaparral understory. Incense-cedar (Calocedrus decurrens) dominated the midstory, and pointleaf manzanita (Arctostaphylos pungens) was the dominant understory shrub. Burn size was approximately 6 ha [2].
The first of the 2 Granite Springs fires was conducted on a mixed-conifer Jeffrey pine-California black oak woodland with a chaparral shrub/deergrass (Muhlenbergia rigens) understory. Pointleaf manzanita was the dominant understory shrub. The burn was approximately 85 ha in size. The second fire was on a deergrass meadow and was 0.1 ha in size. Associated species in the deergrass meadow included American bird's-foot trefoil (Lotus unifoliolatus), common yarrow (Achillea millefolium), and California goldenrod (Solidago californica) [2].
The first of the 2 Oakzanita fires was also conducted on a mixed-conifer Jeffrey pine-California black oak woodland. The understory was chaparral shrubs, dominated by pointleaf manzanita. Eastern Mojave buckwheat (Eriogonum fasciculatum) and California buckthorn (Frangula californica) were common associates. The mixed-conifer burn was approximately 1.2 ha in size. The second fire was on a deergrass meadow and was 0.1 ha in size [2].
Study sites probably experienced the historic fire regimes described in the LANDFIRE Biophysical Settings section.
Plant Phenology
Plant phenology was not described. Plants would have been actively growing during the spring fires and dormant during the late fall fires.
Fire Description
In April 1978, Cuyamaca Rancho State Park staff initiated a prescribed burning program to restore frequent fire in Cuyamaca Rancho State Park communities. The purpose of this study was to evaluate the effectiveness of prescribed fires in reducing understory shrubs in mixed-conifer woodlands and in increasing grass productivity for wildlife in mountain meadows [2].
An adjacent, unburned control was used for comparison at each burn site. Conditions on burning days were [1,2]:
| Site and plant community | Date | Air temperature (°C) | Relative humidity (%) | 10-hr fuelstick moisture content (%) | Windspeed (km/hr) |
|---|---|---|---|---|---|
| Paso Picacho, mixed-conifer/chaparral fire | 24 Apr 1978 | 18 | 30 | 9-12 | ≤16 |
| Granite Springs, mixed-conifer/chaparral/deergrass and deergrass meadow fires | 11-15 Dec 1978 | 13 | 17-37 | 7.5 | 4.0-9.6 |
| Oakzanita, mixed-conifer fire | 3 Dec 1979 | 18-25 | 18-25 | 6-8 | 0-6.4 |
| Oakzanita, deergrass meadow fire | 16 Apr 1980 | — | — | — | — |
Fire Effects on Plant Community
Mixed-conifer fires
Trees and Shrubs
Most shrubs were killed or top-killed. The fires had little impact on saplings or larger trees. Across sites, there were no significant differences in tree density or basal area between burned and unburned control sites in postfire year 2 [1,2,3]. The postfire year 2 survey showed the Paso Picacho fire reduced total density of trees and shrubs 15.3% compared to the control. Tree density reduction was not statistically significant; however, shrubs were reduced 91% compared to the control (P<0.1). Total density (all size classes) of pointleaf manzanita, the dominant understory shrub, was reduced 10.9% (P<0.02). Most top-killed shrubs were in the 2- to 8-cm DBH size class. Results were similar at Granite Springs and Oakzanita [2]: Most shrub reduction was in the 2- to 8-cm size class. At Granite Springs, shrubs were reduced 13% (P<0.05) compared to the control; reduction at Oakzanita was 60% (P not reported). At Oakzanita, some pointleaf manzanitas grew in clumped "islands" surrounded by ground too bare to carry fire. Pointleaf manzanitas on islands generally escaped the fire [2]; however, pointleaf manzanita dominance was still reduced 93% compared to the unburned control [2,3]. By postfire year 1.5, Eastwood manzanita, chaparral whitethorn, Palmer ceanothus, birchleaf mountain-mahogany, and skunkbush sumac were sprouting from root crowns or lignotubers on all burned sites where they were present before the fires [1]. Density and dominance of trees and shrubs are shown in the 3 tables below. Relative dominance is based on relative basal area [2].
| Site | Vegetation type | Density (plants/ha) | Relative dominance (%) | ||
|---|---|---|---|---|---|
| Burn | Control | Burn | Control | ||
| Paso Picacho | Shrubs | 43 | 480 | 2.96 | 16.42 |
| Trees | 1,039 | 1,165 | 97.04 | 83.59 | |
| Granite Springs | Shrubs | 3 | 31 | 0.11 | 1.44 |
| Trees | 345 | 369 | 99.99 | 98.56 | |
| Oakzanita | Shrubs | 240 | 3,529 | 12.45 | 54.28 |
| Trees | 407 | 374 | 87.55 | 46.40 | |
| Total | Shrubs | 286 | 4,040 | 3.91 | 32.25 |
| Trees | 1,917 | 1,782 | 96.09 | 67.75 | |
| Site | Species | Density (plants/ha) | Relative dominance (%) | ||
|---|---|---|---|---|---|
| Control | Burn | Control | Burn | ||
| Paso Picacho | white fir | 3 | 4 | 0.11 | 0.03 |
| incense-cedar | 760 | 846 | 31.75 | 44.28 | |
| limber pine | 3 | —* | 0.11 | — | |
| Jeffrey pine | 236 | 77 | 46.03 | 17.14 | |
| coast live oak | 43 | — | 2.06 | — | |
| canyon live oak | 30 | 77 | 1.11 | 4.14 | |
| California black oak | 47 | 35 | 15.87 | 18.00 | |
| pointleaf manzanita | 40 | — | 2.86 | — | |
| Palmer ceanothus | 3 | — | 0.05 | — | |
| oceanspray | — | 4 | — | <0.01 | |
| Granite Springs | Jeffrey pine | 218 | 169 | 48.89 | 50.00 |
| coast live oak | — | 79 | — | 4.12 | |
| California black oak | 127 | 121 | 51.10 | 44.44 | |
| Eastwood manzanita | — | 7 | — | 0.36 | |
| pointleaf manzanita | — | 24 | — | 1.08 | |
| birchleaf mountain-mahogany | 3 | — | 0.11 | — | |
| Oakzanita | Jeffrey pine | 107 | 209 | 24.22 | 17.50 |
| coast live oak | 273 | 137 | 49.22 | 23.20 | |
| California scrub oak | — | 10 | — | 1.50 | |
| California black oak | 27 | 28 | 14.11 | 5.70 | |
| Eastwood manzanita | — | 28 | — | 1.00 | |
| pointleaf manzanita | 233 | 3,318 | 12.43 | 48.40 | |
| chaparral whitethorn | — | 18 | — | 0.20 | |
| Palmer ceanothus | — | 18 | — | 0.80 | |
| birchleaf mountain-mahogany | 7 | 9 | 0.02 | 0.08 | |
| eastern Mojave buckwheat | — | 73 | — | 0.20 | |
| California buckthorn | — | 55 | — | 2.10 | |
| *not present | |||||
Relative coverage by size class was [2]:
| Site, plot type | Species | Size class (DBH in cm) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 2-8 | 9-16 | 17-24 | 25-32 | 33-40 | 41-48 | 49-56 | 57+ | Total (%) | ||
| Paso Picacho, burn plots | white fir | —* | 0.28 | — | — | — | — | — | — | 0.28 |
| incense-cedar | 19.94 | 27.06 | 8.83 | 4.27 | 1.42 | 2.28 | 0.85 | 0.57 | 65.24 | |
| limber pine | — | 0.28 | — | — | — | — | — | — | 0.28 | |
| Jeffrey pine | 2.28 | 6.56 | 3.42 | 1.42 | 2.28 | — | 2.28 | 1.99 | 20.28 | |
| coast live oak | 1.71 | 0.28 | 0.57 | 0.85 | — | 0.28 | — | — | 3.70 | |
| canyon live oak | — | 0.85 | — | — | — | — | — | — | 2.56 | |
| California black oak | — | 0.57 | 0.28 | 0.28 | 0.28 | 1.14 | 0.85 | 0.57 | 3.99 | |
| pointleaf manzanita | 0.57 | 0.57 | 1.14 | 0.85 | — | — | 0.28 | — | 3.42 | |
| Palmer ceanothus | — | 0.28 | — | — | — | — | — | — | 0.28 | |
| Size class totals | 24.50 | 37.59 | 15.09 | 7.69 | 3.98 | 3.70 | 4.26 | 3.13 | — | |
| Paso Picacho, control plots | white fir | 0.26 | — | — | — | — | — | — | — | 0.26 |
| incense-cedar | 17.95 | 16.92 | 8.72 | 4.87 | 3.85 | 3.08 | 0.26 | 0.77 | 56.41 | |
| Jeffrey pine | 1.03 | 0.51 | 0.26 | 0.51 | 0.51 | 0.51 | 0.51 | 0.26 | 4.10 | |
| canyon live oak | 2.82 | 1.79 | — | 0.51 | — | — | — | — | 5.13 | |
| California black oak | — | 0.26 | — | 0.26 | — | — | 1.03 | 0.77 | 2.31 | |
| pointleaf manzanita | 12.31 | 8.46 | 5.38 | 1.54 | 0.51 | 0.26 | — | 0.51 | 28.97 | |
| Palmer ceanothus | — | 0.77 | 0.51 | 0.77 | 0.51 | — | — | — | 2.56 | |
| oceanspray | 0.26 | — | — | — | — | — | — | — | 0.26 | |
| Size class totals | 34.63 | 28.71 | 14.87 | 8.46 | 5.38 | 3.85 | 1.80 | 2.31 | — | |
| Granite Springs, burn plots | Jeffrey pine | — | 0.9 | — | — | — | — | — | — | 0.9 |
| coast live oak | — | — | — | — | — | — | — | — | — | |
| California black oak | — | 0.9 | 3.5 | 7.0 | 4.3 | 8.7 | 4.3 | 7.8 | 36.5 | |
| Eastwood manzanita | — | — | — | — | — | — | — | — | — | |
| pointleaf manzanita | — | — | — | — | — | — | — | — | — | |
| birchleaf mountain-mahogany | — | 0.9 | — | — | — | — | — | — | 0.9 | |
| Granite Springs, control plots | Jeffrey pine | 7.8 | 2.6 | 6.0 | 6.0 | 5.2 | 6.0 | 5.2 | 3.5 | 42.3 |
| coast live oak | 16.4 | 0.9 | — | — | 1.7 | — | 0.9 | — | 19.9 | |
| California black oak | 0.9 | 0.9 | 4.3 | 5.2 | 7.8 | 6.0 | 3.5 | 1.7 | 30.3 | |
| Eastwood manzanita | — | 0.9 | 0.9 | — | — | — | — | — | 1.8 | |
| pointleaf manzanita | 2.6 | 1.7 | 0.9 | 0.9 | — | — | — | — | 6.1 | |
| birchleaf mountain-mahogany | — | — | — | — | — | — | — | — | — | |
| *not present | ||||||||||
Sapling Trees and Shrubs
The fires significantly reduced total density of sapling trees and shrubs (2-8 inches DBH) compared to unburned controls [1,2,3]. Reduction of sapling trees and shrubs across sites was 94% in postfire year 2. Due to postfire sprouting, mean density of 2- to 8-cm coast live oak, canyon oak, and California black oak increased after burning on most sites, while conifer density was less on burned sites compared to controls [3]. At Paso Picacho, sapling density on 100-m² plots was reduced 90% on the burn compared to the unburned control (P<0.01) in postfire year 2. Incense-cedar saplings comprised over 89% of saplings in burn and control plots, and both incense-cedar and canyon live oak saplings showed significant (P<0.02) reductions in density on burned plots. At Granite Springs, total sapling density was significantly reduced (P<0.01), with Jeffrey pine showing greatest change in density. Jeffrey pines comprised 85% of total saplings on control plots. In postfire year 2, Jeffrey pine density was significantly reduced (P<0.01) on burned 100-m² plots compared to control plots. Total tree sapling reduction on 100-m² burn plots at Oakzanita was significant at P<0.05, even though total tree sapling density was low on control plots. At Oakzanita, 1-m² plots were used in addition to 100-m² plots. On 1-m² quadrats, total sapling density showed an 88% increase due to sprouting shrubs. Eastern Mojave buckwheat and skunkbush sumac were the only 2 species common to both burned and control plots, and both species increased on 1-m² burned plots compared to controls. Sapling tree and shrub density and relative dominance are shown in the 2 tables below [2].
| Site | Species | Density (plants/ha) | Relative dominance (%) | ||
|---|---|---|---|---|---|
| Burn | Control | Burn | Control | ||
| Paso Picacho | white fir | —* | 4 | — | 0.23 |
| incense-cedar | 97 | 1,562 | 97.00 | 89.62 | |
| Jeffrey pine | — | 8 | — | 0.46 | |
| coast live oak | 3 | 15 | 3.00 | 0.86 | |
| canyon live oak | — | 104 | — | 5.96 | |
| California black oak | — | 27 | — | 1.55 | |
| Palmer ceanothus | — | 23 | — | 1.32 | |
| Granite Springs | Jeffrey pine | 3 | 72 | 50.00 | 84.71 |
| coast live oak | — | 10 | — | 11.76 | |
| California black oak | — | 3 | — | 3.53 | |
| birchleaf mountain-mahogany | 3 | — | 50.00 | — | |
| Oakzanita | Jeffrey pine | — | 9 | — | 16.67 |
| coast live oak | — | 36 | — | 66.67 | |
| California black oak | — | 9 | — | 16.67 | |
| birchleaf mountain-mahogany | 7 | — | 100.00 | — | |
| *not present | |||||
| Species | Density (plants/m²) | Relative dominance (%) | ||
|---|---|---|---|---|
| Burn | Control | Burn | Control | |
| eastern Mojave buckwheat | 1.10 | 0.15 | 47.21 | 55.56 |
| Wright's buckwheat | —* | 0.05 | — | 18.52 |
| southern honeysuckle | 0.02 | — | 0.86 | — |
| California buckthorn | — | 0.05 | — | 18.52 |
| skunkbush sumac | 0.10 | 0.02 | 4.29 | 7.42 |
| California rose | 0.22 | — | 9.44 | — |
| Parish's snowberry | 0.82 | — | 35.19 | — |
| poison-oak | 0.07 | — | 3.00 | — |
| *not present | ||||
Seedlings
Total tree and shrub seedling density decreased at Paso Picacho and Granite Springs compared to control plots, but total tree and shrub seedling density greatly increased at Oakzanita. Most of the reductions were from mortality of trees in the smallest size class, particularly incense-cedar. Total shrub seedling density increased on burned plots compared to unburned plots. At Paso Picacho, tree and shrub seedlings were reduced 62% on burned plots, with incense-cedar seedlings showing greatest reduction in density (P<0.01). Pointleaf manzanita and Palmer ceanothus seedling densities increased approximately 85% compared to control plots. Coast live oak and canyon live oak showed moderate increases in seedling density, while California black oak and Jeffrey pine seedling density slightly decreased compared to control plots. Birchleaf mountain-mahogany seedlings showed minor coverage in the Granite Springs postfire community. At Granite Springs, total tree and shrub seedling density was reduced 76% compared to controls. Jeffrey pine (P<0.02), California black oak (P<0.02), and coast live oak (P<0.01) seedling densities were significantly reduced on burn plots. At Oakzanita, there was no significant difference between total tree and shrub seedling density between burned and unburned 100-m² plots. On 1-m² plots, however, there was a substantial increase (41%) in total tree and shrub seedling density. Most of the increase was due to coast live oak seedling establishment. Pointleaf manzanita and Palmer ceanothus also showed density gains compared to unburned controls. In contrast to the Paso Picacho and Granite Springs sites, California black oak seedling density increased after burning at Oakzanita [2].
| Site | Species | Density (plants/ha) | Relative dominance (%) | ||
|---|---|---|---|---|---|
| Burn | Control | Burn | Control | ||
| Paso Picacho | incense-cedar | 287 | 3.096 | 17.89 | 72.90 |
| Jeffrey pine | 3 | 8 | 0.18 | 0.19 | |
| coast live oak | 137 | 27 | 8.54 | 0.64 | |
| canyon live oak | 197 | 169 | 12.28 | 3.98 | |
| California black oak | 700 | 912 | 43.64 | 21.47 | |
| pointleaf manzanita | 30 | 4 | 1.87 | 0.09 | |
| Palmer ceanothus | 250 | 31 | 15.58 | 0.72 | |
| Granite Springs | Jeffrey pine | 9 | 48 | 2.02 | 2.66 |
| coast live oak | 79 | 710 | 17.71 | 39.31 | |
| California black oak | 352 | 1,048 | 78.92 | 58.03 | |
| Palmer ceanothus | 6 | —* | 1.35 | — | |
| Oakzanita | Jeffrey pine | — | 18 | — | 0.44 |
| coast live oak | 5,375 | 3,909 | 62.87 | 95.34 | |
| California black oak | 3,075 | 91 | 35.96 | 2.22 | |
| pointleaf manzanita | 25 | 82 | 0.29 | 2.00 | |
| Palmer ceanothus | 75 | — | 0.88 | — | |
| *not present. | |||||
| Species | Density (plants/m²) | Relative dominance (%) | ||
|---|---|---|---|---|
| Burn | Control | Burn | Control | |
| Jeffrey pine | —* | 0.02 | — | 1.72 |
| coast live oak | 5.62 | 1.07 | 94.77 | 92.24 |
| California black oak | 0.12 | 0.07 | 2.02 | 6.03 |
| pointleaf manzanita | 0.02 | — | 0.34 | — |
| eastern Mojave buckwheat | 0.07 | — | 1.18 | — |
| Palmer ceanothus | 0.10 | — | 1.69 | — |
| *not present | ||||
Herbaceous Vegetation
The prescribed burns increased total herbaceous vegetation density at Paso Picacho but decreased total herb density at Oakzanita. At Paso Picacho, mean total herb density was 107.7% that of herb density on control plots in postfire year 2. At Oakzanita, total herb density decreased 22%, but total herb diversity increased. The decrease in density was mainly due to the dominance of California goldenrod on control plots. Fifty percent of total herb density on control plots was California goldenrod, and California goldenrod density was reduced 39% on burn plots compared to control plots [2]. Burn and control densities of herbs at Granite Springs were not compared. For herbs, species responses to fire were not measured on any of the mixed-conifer sites.
Deergrass Meadow
The prescribed fires removed nearly all standing vegetation on both meadow sites. Approximately 50% of the standing deergrass biomass before the fires was dead foliage. At Granite Springs, deergrass gained 145% live foliage cover 3 months after prescribed burning compared to control plots [2,3]. At Oakzanita, deergrass showed a 51% gain of live foliar cover at postfire month 15. Deergrass is a bunchgrass, and there were over 3 times more deergrass clumps on the Oakzanita burn compared to the control. However, deergrass clumps were about 5 times larger in the control compared to the burn. Pre- and postfire herbaceous cover of plants at Oakzanita is shown below [2].
| Species | Dominance (% foliar cover) | Relative dominance (%) | ||
|---|---|---|---|---|
| Burn | Control | Burn | Control | |
| common yarrow | 1.00 | 2.67 | 1.48 | 3.11 |
| Cuman ragweed | —* | 1.00 | — | 1.20 |
| attenuate Indian paintbrush | — | 0.33 | — | 0.38 |
| winecup clarkia | 1.67 | 0.67 | 2.48 | 0.78 |
| San Bernardino larkspur | 0.33 | 0.33 | 0.49 | 0.38 |
| tall annual willowherb | 0.33 | 0.33 | 0.49 | 0.38 |
| western marsh cudweed | 1.00 | 1.33 | 1.48 | 1.55 |
| American bird's-foot trefoil | 4.66 | 5.67 | 6.92 | 6.62 |
| dwarf checkerbloom | 3.66 | 1.67 | 5.43 | 1.95 |
| California goldenrod | 7.67 | 2.33 | 11.39 | 2.72 |
| notchleaf clover | 1.00 | — | 1.40 | — |
| squirreltail | 1.00 | — | 1.48 | — |
| smallflower melicgrass | 6.00 | — | 8.91 | — |
| deergrass (live) | 15.33 | 30.33 | 22.70 | 35.49 |
| deergrass (dead) | — | 28.00 | — | 32.69 |
| Kentucky bluegrass | 1.67 | 5.67 | 2.49 | 6.62 |
| Sandberg bluegrass | 1.67 | — | 2.49 | — |
| rattail sixweeks grass | 20.33 | 4.33 | 30.19 | 5.05 |
| *not present | ||||
Recovery of deergrass clumps is shown below [2].
| Site | Treatment | Clumps/plot | Area/clump (m²) | Total basal area (m²) | Dominance (% basal area) |
|---|---|---|---|---|---|
| Granite Springs | Burn | 5593 | 0.014 | 8.04 | 5.39 |
| Control | 194 | 0.060 | 11.72 | 7.82 | |
| Oakzanita | Burn | 12.93 | 0.003 | 0.48 | 3.2 |
| Control | 4.13 | 0.017 | 1.05 | 7.0 |
This study demonstrates that spring or late fall prescribed burning can control woody plant encroachment in both mixed-conifer understories and deergrass mountain meadows of southern California. The dominant shrub, pointleaf manzanita, is a nonsprouter. It was reduced an average of 93% on burned sites and showed relatively little seedling establishment in postfire years 1 and 2. Associated sprouting shrubs (for example, Eastwood manzanita and chaparral whitethorn) were also reduced by prescribed fire, and their recovery was slow as of postfire year 2. Sprouting species will probably regain postfire cover within a few years without frequent prescribed burning [1,2,3].
This study further showed the ability of pole-sized and mature oaks and pines to withstand low-severity prescribed underburning. Frequent prescribed fire generally favors oak species over pointleaf manzanita. Martin [2] found that prescribed late fall fire reduced Jeffrey pine seedling density, so he recommended spring prescribed burning to increase Jeffrey pine seedling establishment. After fire, Jeffrey pine seedlings tend to establish in "hot spots" where fire temperatures cause plant mortality. Lack of vegetation reduces postfire growth interference from herbaceous species, and spring fires may create more hot spots than late fall fires, favoring Jeffrey pine.
The fires demonstrated the effectiveness of spring and late fall underburns in controlling young incense-cedars. Incense-cedar is a late-successional species which, with fire exclusion, eventually replaces oaks and pines . Incense-cedar seedlings and saplings were greatly reduced by the prescribed fires. Incense-cedar seedlings generally show little establishment on new burns, so their establishment would be slight with frequent prescribed fires [2].
Herbaceous species on the deergrass meadows recovered quickly after prescribed burning. Deergrass showed greatly increased productivity after burning, probably due in part to removal of dead material within its clumps. Additionally, blackened soil probably encouraged earlier spring growth on burned sites compared to controls. Although not quantified, deergrass apparently showed increased flower and seed production on burned sites compared to unburned controls. Due to relatively greater recovery of deergrass after the spring burn at Oakzanita compared to the late fall burn at Granite Springs, Martin [2] recommends spring prescribed burning to increase deergrass productivity.
| Biophysical Setting | Mean Fire Interval (years) | Fire Severity Percent (%) | ||||||
|---|---|---|---|---|---|---|---|---|
| Code | Fire Regime Group | Low | Mixed | Replacement | All | Low | Mixed | Replacement |
| Series 10270 - Mediterranean California Dry-Mesic Mixed Conifer Forest and Woodland | ||||||||
| 10270_4_5_6 | I-B | 17 | 35 | 150 | 11 | 62 | 31 | 7 |
| Series 10280 - Mediterranean California Mesic Mixed Conifer Forest and Woodland | ||||||||
| 10280_4_6_7_12 | I-C | 33 | 46 | 148 | 17 | 51 | 37 | 12 |
| Series 11290 - California Central Valley and Southern Coastal Grassland | ||||||||
| 11290_4_5 | II-A | 4 | 4 | 0 | 0 | 100 | ||
| Summary | ||||||||
| Minimum | 17 | 35 | 4 | 4 | 0 | 0 | 7 | |
| Maximum | 33 | 46 | 150 | 17 | 62 | 37 | 100 | |
| Mean | 25 | 41 | 101 | 11 | 38 | 23 | 40 | |
| Median | 25 | 41 | 148 | 11 | 51 | 31 | 12 | |
| 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 |
|---|---|
| Trees | |
| white fir | Abies concolor |
| incense-cedar | Calocedrus decurrens |
| limber pine | Pinus flexilis |
| Jeffrey pine | Pinus jeffreyi |
| coast live oak | Quercus agrifolia |
| canyon live oak | Quercus chrysolepis |
| California black oak | Quercus kelloggii |
| Shrubs | |
| Eastwood manzanita | Arctostaphylos glandulosa |
| pointleaf manzanita | Arctostaphylos pungens |
| Palmer ceanothus | Ceanothus palmeri |
| chaparral whitethorn | Ceanothus leucodermis |
| birchleaf mountain-mahogany | Cercocarpus montanus var. glaber (Cercocarpus betuloides)* |
| eastern Mojave buckwheat | Eriogonum fasciculatum |
| Wright's buckwheat | Eriogonum wrightii |
| oceanspray | Holodiscus discolor |
| southern honeysuckle | Lonicera subspicata |
| California scrub oak | Quercus berberidifolia (Q. dumosa)* |
| California buckthorn | Frangula californica |
| skunkbush sumac | Rhus trilobata |
| California rose | Rosa californica |
| Parish's snowberry | Symphoricarpos parishii |
| poison-oak | Toxicodendron diversilobum |
| Forbs | |
| common yarrow | Achillea millefolium |
| Cuman ragweed | Ambrosia psilostachya |
| attenuate Indian paintbrush | Castilleja attenuata (Orthocarpus attenuatus) |
| winecup clarkia | Clarkia purpurea |
| San Bernardino larkspur | Delphinium parryi |
| tall annual willowherb | Epilobium brachycarpum (Epilobium paniculatum) |
| western marsh cudweed | Gnaphalium palustre |
| American bird's-foot trefoil | Lotus unifoliolatus (Lotus purshianus) |
| dwarf checkerbloom | Sidalcea malviflora |
| California goldenrod | Solidago californica |
| notchleaf clover | Trifolium bifidum |
| Grasses | |
| squirreltail | Elymus elymoides (Sitanion hystrix) |
| smallflower melicgrass | Melica imperfecta |
| deergrass | Muhlenbergia rigens |
| Kentucky bluegrass | Poa pratensis |
| Sandberg bluegrass | Poa secunda (Poa scabrella) |
| rattail sixweeks grass | Vulpia myuros |
| *For species that have undergone scientific name changes, names in parentheses are those used in the research papers. | |
1. Lathrop, Earl W.; Martin, Bradford D. 1982. Response of understory vegetation to prescribed burning in yellow pine forests of Cuyamaca Rancho State Park, California. Aliso. 10(2): 329-343. [15943]
2. Martin, Bradford D. 1981. Vegetation responses to prescribed burning in a mixed-conifer woodland, Cuyamaca Rancho State Park, California. Loma Linda, CA: Loma Linda University. 112 p. Thesis. [64684]
3. Martin, Bradford D. 1982. Vegetation responses to prescribed burning in Cuyamaca Rancho State Park, California. In: Conrad, C. Eugene; Oechel, Walter C., technical coordinators. Proceedings of the symposium on dynamics and management of Mediterranean-type ecosystems; 1981 June 22-26; San Diego, CA. Gen. Tech. Rep. PSW-58. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 617. [6088]