State 1
Native and introduced perennial and annual grasses and forbs

Community 1.1
Native and introduced perennial and annual grasses and forbs

Plant Community 2. The interpretive plant community is dominated by both native and introduced perennial and annual grasses, including bristly dogstail grass (Cynosurus echinatus), soft brome (Bromus hordeaceus), and tall oatgrass (Arrhenatherum elatius). Native perennial grasses present include blue wildrye (Elymus glaucus), California oatgrass (Danthonia californica), and Canada wildrye (Elymus canadensis). 2a) Repeated fire, either natural or prescribed, would tend to perpetuate this community. 2b) The plant community could be altered by uncontrolled grazing or fire exclusion. These factors, either apart or in conjunction, may cause the community to be more heavily dominated by tall oatgrass, bristly dogstail grass, and hairy catsear. Native perennial grasses are still present but their populations are diminished. See PC#3. 2c) Fire exclusion may lead to a gradual invasion of prairie by some brush species, including scotch broom (Cytisus scoparius) and coyotebrush (Baccharis pilularis), as well as an increase in the annual bristly dogstail grasses. See PC# 4. 2d) With fire exclusion, Douglas-fir (Pseudotsuga menziesii) may gradually invade prairies. Disturbances such a road building or harvesting could expose mineral soil and provide a seedbed for natural regeneration of Douglas-fir. See PC#5.

Forest understory. Species Composition % by weight

bristly dogstail grass 0-29
soft brome 5-54
blue wildrye 5-38
California oatgrass 0-2
Canada wild rye 0-7
annual vernal grass 0-22
western brakenfern 0-9

Total dry weight production:

Favorable year: 6,800 lbs./acre
Normal Year: 4,000 lbs./acre
Unfavorable year: 3,000 lbs./acre

State 2
Native perennial grasses and forbs

Community 2.1
Native perennial grasses and forbs

Plant Community 1. The historic climax plant community (HCPC) was thought to have been dominated by native perennials that included blue wildrye (Elymus glaucus), California oatgrass (Danthonia californica), bentgrass (Agrostis spp.), and Canada wildrye (Elymus canadensis). The annual forb, miniature lupine (Lupinus bicolor), is also thought to have been common (Arguello, pers. comm.). 1a) Periodic burning by Native Americans maintained the prairies. Blue wildrye, a bunchgrass, is believed to be favored by burning (Johnson, 1999). Lupine species are seed-bankers and respond favorably to fire through the sprouting or germination of buried seed (Meyer, R., 2006). 1b) With the influx of European settlements in the mid-1800s, regular burning of the prairies ceased. Grazing of domestic livestock along with range seeding led to an increase in both the introduced perennial and annual grasses and forbs. These introduced perennials included tall oatgrass (Arrhenatherum elatius). Introduced annuals included bristly dogstail grass (Cynosurus echinatus), soft brome (Bromus hordeaceus), and annual vernalgrass (Anthoxanthum aristatum). Perennial forbs that are present may include western brackenfern (Pteridium aquilinum) and hairy catsear (Hypochaeris radicata). Native perennials such as blue wildrye (Elymus glaucus) and Canada wildrye (Elymus canadensis) have persisted but in smaller numbers. Important factors in the noted decrease of native species include competition from the more aggressive introduced grasses, as well as the exclusion of fire. 1c) Uncontrolled grazing and fire exclusion are both important factors regarding the dominance of introduced species such as the perennial, tall oatgrass (Arrhenatherum elatius), and bristly dogstail grass (Cynosurus echinatus), which is an introduced annual. Hairy catsear (Hypochaeris radicata), and western brakenfern (Pteridium aquilinum), both perennial forbs, may also be more abundant. Native perennials continue to persist on the site, but their ability to propagate is diminished. See PC#3.

State 3
Introduced perennial and annual grasses and forbs

Community 3.1
Introduced perennial and annual grasses and forbs

Plant Community 3. The plant community is dominated by tall oatgrass (Arrhenatherum elatius), an introduced perennial, as well as the annual, bristly dogstail grass (Cynosurus echinatus). Forbs such as hairy catsear (Hypochaeris radicata) may also be common. 3a) Prescribed fire and mechanical treatments, such as seed drilling, may assist in the reestablishment of some native grasses, though not to historic levels. See PC#2. 3b) Fire exclusion and uncontrolled grazing may gradually infill bare areas with shrubs such as scotch broom (Cytisus scoparius) or coyotebrush (Baccharis pilularis). Annual grasses and forbs are present in the understory. See PC#4. 3c) Fire exclusion or disturbance may cause this plant community to be gradually invaded by Douglas-fir (Pseudotsuga menziesii). See PC#5.

State 4
Scotch broom-coyotebrush/annual grasses and forbs

Community 4.1
Scotch broom-coyotebrush/annual grasses and forbs

Plant Community 4. This plant community reflects the encroachment of shrubs, including scotch broom (Cystisus scoparius) and coyotebrush (Baccharis pilularis). Annual grasses such as bristly dogstail may increase. 4a) Prescribed fire or mechanical treatment, along with seeding of native grasses, could help to reestablish native perennials, though not to historic population levels. See PC#2. 4b) With continued fire exclusion or disturbance, infill of Douglas-fir (Pseudotsuga menziesii) from adjacent forest edges is likely. See PC#5.

State 5
Douglas-fir

Community 5.1
Douglas-fir

Plant Community 5. The prairie is infilled with seeds from the adjacent forests creating a dense, single-storied stand of Douglas-fir (Pseudotsuga menziesii). 5a) Gradually over time, and with continued fire exclusion, an infill of tanoak (Lithocarpus densiflorus) may occur in the shade of the conifers. See PC#6. 5b) Management in the early stages of conifer encroachment could temporarily reverse successive progression. Activities could include prescribed fire, tree gridling, or mechanical treatment, in combination with the seeding of native grasses. Periodic fire would be required to keep the prairies free from further conifer infill. See PC#2. 5c) Fire introduced to young Douglas-fir stands could kill the trees and temporarily halt conifer encroachment. See PC#4.

State 6
Douglas-fir-tanoak

Community 6.1
Douglas-fir-tanoak

Plant Community 6. The plant community is dominated by Douglas-fir (Pseudotsuga menziesii) in the overstory and tanoak (Lithocarpus densiflorus) in the sub-canopy. 6a) If left undisturbed over a long time period, infill of redwood (Sequoia sempervirens) from adjacent forest stands could encroach into the Douglas-fir/tanoak stand. Gradually, redwood would become co-dominant with the Douglas-fir. See PC#7. 6b) Chemical control of tanoak could lead to a stand dominated by Douglas-fir. See PC#5.

State 7
Douglas-fir-redwood-tanoak

Community 7.1
Douglas-fir-redwood-tanoak

Plant Community 7. Gradually, redwood and Douglas-fir become co-dominate in the overstory. Tanoak is present in the sub-canopy. 7a) Following block harvesting or fire, the plant community could be temporarily dominated by Douglas-fir and tanoak. See PC#6.