State 1
Reference State - Plant Community 2.1

Community 1.1
Reference State - Plant Community 2.1

This state is similar to the reference state, PC 1.1, and is still dominated by chamise and Channel Island scrub oak, however it is now intermixed with a non-native annual grassland understory. Community Pathway 2.1a: The shift from PC 2.1 to PC 2.2 occurs under a fire regime of approximately 70 to 200 years, with lightning being the primary ignition source. Fires have generally increased to 40 to 50 years due to an increase in human-caused fires since the arrival of European settlers. Fires result in a decrease in shrub cover and an increase in the non-native understories dominated by exotic annual grasses. Community Pathway 2.1b: The shift from PC 2.1 to PC 2.3 occurs if fires become more frequent (less than 10 year intervals). Non-natural grazing by livestock and non-native wildlife can also push PC 2.1 towards PC 2.3.

State 2
Plant Community 1.2

Community 2.1
Plant Community 1.2

After a fire, the amount of bare soil will be high. There will probably be some resprouting of prostrate chamise (Adenostoma fasciculatum var. prostratum), Channel Island scrub oak (Quercus pacifica), and Santa Rosa Island Manzanita (Arctostaphylos confertiflora) from the root crowns, which could create a canopy with a cover between 0 to 24 percent. Some species, such as chamise, will produce abundant seedlings. Scattered native grasses and annual forbs will germinate from seed and resprout from rhizomes to create an herbaceous understory. Community Pathway 1.2a: The shift from PC 1.2 back to PC 1.1 generally occurs 1 to 3 years after a fire event. Given an extended period of time without disturbance from fires or grazing, new shrubs will resprout and begin to increase in size and cover. Prostrate chamise, Channel Island scrub oak, and Santa Rosa Island Manzanita will continue to increase in cover, eventually reaching the pre-fire canopy cover. Community Pathway 1.2b: The shift from PC 1.2 to PC 1.3 will take place under continued grazing or frequent fires (less than 10 year intervals). These disturbances will hinder the new growth of shrubs, leading to a state dominated by native perennial and annual herbaceous species.

State 3
Plant Community 1.3

Community 3.1
Plant Community 1.3

If frequent fire or heavy grazing continually impacts the site, the regeneration of the shrubs will be negatively affected. The cover of shrubs will remain low, and the percent of bare ground will increase. Gullies may form in the bare areas. Other vegetative cover also remains low, due to the shallow droughty soils and the extreme wind exposure of this area. Community Pathway 1.3: The shift PC 1.3 back to PC 1.2 could occur after an extended time without disturbance, and in conjunction with restoration efforts. Transition 1: Continued frequent fires and non-natural grazing by livestock and non-native wildlife can place a stress on PC 1.3. This pressure can give an advantage to encroaching non-native plant species and may lead to the invasion of non-native annual grasslands.

State 4
Historic State - Plant Community 1.1

Community 4.1
Historic State - Plant Community 1.1

This community is dominated by prostrate chamise (Adenostoma fasciculatum var. prostratum) and Channel Island scrub oak (Quercus pacifica). Other common species include Santa Rosa Island Manzanita (Arctostaphylos confertiflora), bush monkeyflower (Mimulus longiflorus), and island monkey flower (Mimulus flemingii). The shrubs are less than 2 feet high, with open patches of gravel and bare soil. In adjacent wind sheltered areas, Channel Island scrub oak (Quercus pacifica) will grow taller, with toyon (Heteromeles arbutifolia) as a common associate. Community Pathway 1.1a: The shift from PC 1.1 to PC1.2 occurs under the natural fire regime of approximately 70 to 200 years. Fire results in a decrease in shrub cover and an increase in the native herbaceous understory community. Community Pathway 1.1b: The shift from PC 1.1 to PC 1.3 occurs if fires become more frequent (less than 10 year intervals). Non-natural grazing by livestock and non-native wildlife can also push PC 1.1 towards PC 1.3.

State 5
Plant Community 2.2

Community 5.1
Plant Community 2.2

This community is dominated by non-native annual grasslands, which will grow well while the canopy is open during the first couple of years following a fire. Most of the chamise and Channel Island scrub oak will recover and grow after a fire, which will eventually lead back to PC 2.1. Community Pathway 2.2a: The shift from PC 2.2 back to PC 2.1 generally occurs after an extended period of time without disturbance by fire or grazing. New chamise and Channel Island scrub oak will resprout and begin to increase in size and cover. Eventually, the non-native annual grasslands will start to diminish as they are shaded out by the shrubs. Community Pathway 2.2b: The shift from PC 2.2 to PC 2.3 will take place under continued grazing or frequent fires (less than 10 year intervals). These disturbances will hinder the new growth of shrubs, leading to a state dominated by annual grasses and forbs.

State 6
Plant Community 2.3

Community 6.1
Plant Community 2.3

If frequent fire or heavy grazing continually impacts this site, the regeneration of the shrubs will be considerably hindered. Annual non-native grasses and forbs will dominate as the cover of shrubs remains low and the percent bare ground increases. Community Pathway 2.3: The shift from PC 2.3 back to PC 2.2 could occur after an extended time without disturbance, and in conjunction with restoration efforts. Transition 2: Continual grazing as well as frequent fires occurring more often than the natural range could transition PC 2.3 into a long term state.

State 7
State 3 - Plant Community 3.1

Community 7.1
State 3 - Plant Community 3.1

This state is dominated by annual grasses and forbs with no chamise or Channel Island scrub oak present. Extensive restoration efforts could transition this state back to PC 2.2.