State 1
Scotch broom-coyotebrush/western brackenfern-annual grasses and forbs

Community 1.1
Scotch broom-coyotebrush/western brackenfern-annual grasses and forbs

Plant Community 4. The scotch broom/coyotebrush/western brackenfern, annual grasses, and forbs plant community is one that develops in areas that have been cultivated or disturbed, or areas from which fire has been excluded. Coyotebrush and scotch broom readily invade both disturbed and undisturbed areas, particularly along roadsides. Coyotebrush (Baccharis pilularis) establishes via seed and is capable of sprouting following fire (Steinberg, 2002). Scotch broom (Cystisus scoparius) is an invasive shrub that reproduces via seed and maintains itself through prolific seeding and vegetative sprouting (Zouhar, 2005). Western brackenfern reproduces primarily vegetatively and via spores (Crane, 1990). Populations of western brackenfern appear to be favored by fire through the sprouting of rhizomes. Areas are also rapidly colonized by new plants established from spores (Page, 1986). Biomass production of perennial and annual grasses and forbs generally increase following fire (Heady, 1972). 4a) Prescribed fire may temporarily reduce populations of shrubs and forbs in grassland communities. The intensity and timing of prescribed fire has varying effects on plant response and are not well understood, and long-term studies on the effects of burning are lacking (Antonio et al). Seeding following a spring burn could help to establish native perennial populations where they are lacking (Wilson and Clark, 1998). Mechanical treatment of shrubs and the reestablishment of some native grasses through seeding may be possible, though not to historic levels. See PC# 2. 4b) With fire exclusion, Douglas-fir may gradually invade into prairies. Road building and soil disturbance from harvesting activities also make a desirable seedbed for Douglas-fir natural regeneration (Sugihara and Reed, 1987).

State 2
Douglas-fir-redwood-tanoak

Community 2.1
Douglas-fir-redwood-tanoak

Plant Community 8. The plant community is dominated by Douglas-fir and redwood (Sequoia sempervirens) in the overstory and tanoak in the sub-canopy. At the lower elevations on this site redwood could dominate over Douglas-fir.

State 3
Douglas-fir

Community 3.1
Douglas-fir

Plant Community 5. This plant community is primarily composed of Douglas-fir (Pseudotsuga menziesii) that has infilled from adjacent seed sources. Invasion of prairie and oak woodland by conifers has lead to a conversion to forests in a very short period of time (Sugihara and Reed, 1987). 5a) Over a period of time, without fire, tanoak (Lithocarpus densiflorus) may infill from adjacent seed sources. Seedling infill will accumulate over time without disturbance, and significant amounts may take several decades to develop under conifer stands (Tappeiner, et al, 1986). See PC#6. 5b) The grassland community could be restored with the use of fire or tree girdling, mechanical treatment, and reestablishment of native grasses if the succession to conifers is in the early stages. See PC#2. 5c) If fire were introduced into the system in the early stages of conifer encroachment, the natural succession process could be temporarily halted and set back to shrubs. See PC# 4.

State 4
Annual grasses and forbs

Community 4.1
Annual grasses and forbs

Plant Community 3. This plant community is composed of annual grasses and forbs that may include bristly dogstail (Cynosurus echinatus), annual vernalgrass (Anthoxanthum aristatum), silver hairgrass (Aira caryophyllea), soft chess (Bromus hordeaceous), rattail fescue (Vulpia myuros), and velvet grass (Holcus lantanus). Common forbs include: hairy catsear (Hypochaeris radicata), curly dock (Rumex crispus) and common sheep sorrel (Rumex acetosella). Western brackenfern (Pteridium aquilinum), a native forb is also commonly found. 3a) Periodic prescribed fire and/or drill seeding may restore some native grass populations, though not to the historic levels. See PC#2. Prescribed grazing and/or prescribed fire could cause a shift from annual grasses and forbs back to a perennial-dominated plant community. More aggressive introduced perennial species such as tall oatgrass continue to be part of the community. Annual vernalgrass, an introduced annual, may also increases in cover. Spring burning may be more successful in reducing tall oatgrass than fall burning (Wilson and Clark, 1998); other studies indicate that spring burning may be detrimental to established native populations such as California oatgrass (National Park Service, 2005). Studies indicate that the effects of fire on native grasses are variable and further study is needed (Antonio et al, date?). 3b) Fire exclusion from the site may allow for the eventual invasion of the site by shrubs including scotch broom (Cystisus scoparius) and coyotebrush (Baccharis pilularis). Disturbance from uncontrolled grazing may leave exposed soil subject to brush invasion. See PC#4.

State 5
Douglas-fir-tanoak

Community 5.1
Douglas-fir-tanoak

Plant Community 6. A Douglas-fir and tanoak plant community develops as a result of fire exclusion and tanoak infill. 6a) With a period of fire exclusion, shade-tolerant redwood seedlings slowly infill over time. Redwood saplings were found in prairies colonized by Douglas-fir 80 to 200 years ago (Sugihara and Reed, 1987). Douglas-fir regeneration may eventually become less successful in the absence of created openings. See PC#8. 6b) The use of chemical control would kill young tanoak, leaving Douglas-fir. See PC#5. 6c) A fire of moderate intensity with partial stand replacement could kill patches of younger Douglas-fir and tanoak. Prolific basal sprouting of tanoak would be expected. Vigorous height growth of tanoak could allow it to dominate the canopy for a period of time. Block harvesting the Douglas-fir/tanoak stand could have similar results. See PC#7.

State 6
Introduced perennial and annual grasses and forbs

Community 6.1
Introduced perennial and annual grasses and forbs

Plant Community 2. The interpretive plant community is dominated by non-native perennial and annual grasses. They include tall oatgrass (Arrhenatherum elatius), orchardgrass (Dactylis glomerata), annual vernalgrass (Anthoxanthum aristatum), and bristly dogstail grass (Cynosurus echinatus). Common perennial and annual forbs include western brackenfern (Pteridium aquilinum), common sheep sorrel (Rumex acetosella), and hairy catsear (Hypochaeris radicata). Native perennial grasses found on the site include blue wildrye (Elymus glaucus), California oatgrass (Danthonia californica) and bentgrass (Agrostis spp.). Species composition by weight % Tall oatgrass 23-25% Annual vernalgrass 10-20% Bristly dogstail 10-15% Bentgrass 2-12% Common velvetgrass 13-15% Soft brome 5-7% Blue wildrye 7-14% California oatgrass 8-11% Western brackenfern 5-10% Hairy catsear 5-10% Sheep sorrel 3-6% Total Dry Weight Production: Dolason Favorable year: 6,800 lbs./acre Average year: 4,500 lbs./acre Unfavorable year: 1,500 lbs./acre Countshill Favorable year: 4,700 lbs./acre Average year: 3,200 lbs.acre Unfavorable year: 1,500 lbs./acre Airstrip Favorable year: 4,700 lbs./acre Average year: 3,100 lbs./acre Unfavorable year: 1,500./lbs/acre 2a) Fire may stimulate growth of native perennials by reducing competition (D'Antonio, et al), but may also increase the amount of introduced perennials and forbs (Keeley, 1981). When fire is re-introduced to the system, varying effects on vegetation may result. Climatic factors influence the effect of fire on vegetation as well as the use of livestock grazing (D'Antonio et al). Burning may cause an increase in native and exotic forbs such as western brackenfern and in introduced perennials such as tall oatgrass. Timing of burning appears to be an important factor affecting the presence of the native perennial California oatgrass (Aguello, 1994, Hatch et al, 1999); cover and frequency may decline with early summer burns versus late summer burning. Spring burning may be more successful in reducing tall oatgrass than fall burning (Wilson and Clark, 1998); other studies indicate that spring burning may be detrimental to established native populations such as California oatgrass (National Park Service, 2005). Studies indicate that the effects of fire on native grasses are variable and further study is needed (Antonio et al, date?) See PC#2. 2b) As with the historic plant community, annual grasses such as bristly dogstail (Cynosurus echinatus) and the forb, hairy catsear (Hypochaeris radicata) may become more prevalent in areas subject to uncontrolled grazing or in areas that have been disturbed. See PC#3. 2c) Western brackenfern (Pteridium aquilinum), coyotebrush (Baccharis pilularis) and scotch broom (Cystisus scoparius) may invade some prairies. Western brackenfern is an aggressive colonizer and its expansion into an area may be increased by fire. Coyotebrush and scotch broom both seed into disturbed areas and sprout following fire. See PC#4. 2d) Fire exclusion or disturbance such as road building may allow for infill of Douglas-fir into prairies. See PC#5.

State 7
Tanoak-Douglas-fir

Community 7.1
Tanoak-Douglas-fir

Plant Community 7. A tanoak and Douglas-fir dominated plant community could develop temporarily following fire or block harvesting, if the disturbance is severe enough. Sprouting tanoak responds vigorously following cutting or burning and initially outgrows any Douglas-fir that becomes established. 7a) Infill of Douglas-fir may occur at the time of disturbance, or residual trees may seed following fire. Over time Douglas-fir will overtop the tanoak and dominate the canopy. See PC#6.

State 8
Native perennial grasses and forbs

Community 8.1
Native perennial grasses and forbs

Plant Community 1. It is thought that native perennial grasses and forbs once dominated the grasslands of the Bald Hills (Holland and Keil, 1995). Native American burning sustained this plant community over several thousand years. Native perennial grasses may have included California oatgrass (Danthonia californica), blue wildrye (Elymus glaucus), and bentgrass (Agrostis spp.). Western brackenfern (Pteridium aquilinum) was a common native forb. 1a) Regular burning of prairies by Native Americans stimulated the growth of grasses and eliminated invading shrubs and trees. Native perennial grasslands are favored by periodic burning. 1b) Uncontrolled grazing may have led to domination of introduced annual grasses and forbs. See PC#3. 1c) With European settlement in the mid-1800s, the use of fire largely ceased. Seeding of introduced perennials was practiced in the Bald Hills area. Uncontrolled grazing of domestic livestock may have also contributed to an increase in annual grasses and forbs (Heady, 1977). Introduced perennials and annuals have out-competed native grasses and dominated the plant community in some areas (Murphy and Ehrlich, 1989). See PC#2.