State 1
Hoaryleaf ceanothus mixed chaparral 1.4

Community 1.1
Hoaryleaf ceanothus mixed chaparral 1.4

This community is the reference community for this state, because it is the most common community present of this state at this time. It is dependent upon fire. The shorter lived hoaryleaf ceanothus is co-dominant at this point. Canopy closure is almost 90 percent, and there is very little understory vegetation. The understory species that are present are found in the canopy gaps. Production data was not collected on this site.

This community may exist for 40 years or more, then the shorter lived species become decadent and chamise becomes dominant (pathway 1.4a) developing into the climax chamise community 1.1.

If fire returns to this community at this point (pathway 1.4b) stand regeneration is initiated.

If a low intensity fire occurs during this phase, this stand could follow pathway 1.4c to the young chaparral community. This pathway is uncommon, and could eventually cause a transition to state 2. The transition to state (T1.1a) 2 may happen if the low intensity fires are not hot enough to scarify the hoaryleaf ceantohus seeds, and allow other species such as Eastern Mojave buckwheat (Eriogonum fasciculatum) and black sage (Salvia mellifera) to become dominant. If these species become dominant, they create lower fuel loads and compact litter which burn at lower intensities. This continues to inhibit the germination of some chaparral shrub seeds.

State 2
Regeneration 1.2

Community 2.1
Regeneration 1.2

This community is dominated by native forbs and grasses, along with resprouting shrubs and shrub seedlings. This phase is short lived because the shrubs rapidly regain dominance in a couple of years. Many of the species present during this phase have stored dormant seeds in the soil, which will not germinate until heat from the fire, sunlight from the removal of the canopy, or nitrogen from the charred wood leachate cue germination. In the first year after a fire thousands of chamise and hoaryleaf ceanothus seedlings will be present. Most of these die by the second year. Chamise will increase in cover from the new shoots sprouting from the surviving lignotubers. There are several annual and perennial fire followers that may be present at this stage, such as: whisperingbells (Emmenanthe penduliflora), largeflower phacelia (Phacelia grandiflora), black sage (Salvia mellifera), yellow bleeding heart (Ehrendorferia ochroleuca formerly Dicentra ochroleuca), bush poppy (Dendromecon rigida), Coulter's snapdragon (Sairocarpus coulterianus formerly Antirrhinum coulterianum), golden eardrops (Ehrendorferia chrysantha formerly Dicentra chrysantha), western poppy (Papaver californicum), and windpoppy (Stylomecon heterophylla) (Thanos and Rundel, 1995; Dagit, 2002). Many of these fire followers are only present the first year or two after a fire.

In the absence of disturbance and the growth of the chaparral shrubs the primary pathway 1.2a in the state and transition model is followed.

If fire frequency is too high then this community may transition to (T1a) State 2 or eventually to (T2a) State 3.

State 3
Chamise chaparral 1.1

Community 3.1
Chamise chaparral 1.1

This community is the historic plant community and it was most likely dominated by chamise (Adenostoma fasciculatum), with some hoaryleaf ceanothus (Ceanothus crassifolius). Other common plants may have included: coastal buckwheat (Eriogonum cinereum), laurel sumac (Malosma laurina), and black sage (Salvia mellifera). NRCS plant composition and production data is lacking on this community partly because this unaltered historic community is difficult to find since fires are now more frequent than they were historically, and non-native plant species are almost always present.
This chaparral community develops after at least 60 years without fire. After enough time has passed without disturbance, the shorter lived fire dependent chaparral species, such as hoaryleaf ceanothus, will become decadent and be replaced by chamise in this area. Chamise is a longer living chaparral species and can continue to produce new shoots from the root crown, even in the absence of fire. Until recently it was believed that frequent fires were needed for fuel reduction and for regeneration of the chaparral species. Fuel studies indicate that just fire five years after a stand replacing fire; the chaparral species have recovered enough to create a fire hazard. Recent studies on shrub regeneration suggest that chaparral communities can exist for 100 years or more without disturbance and still reproduce well after fire, and that short interval fires are actually detrimental to shrub sustainability.

An inherent property of chaparral communities is the high volumes of dead branches and dead woody debris and litter on the ground. The structure and volume of this litter is actually essential for the survival of chaparral. Many chaparral species require high severity fires to initiate break seed dormancy. This heavy fuel load and the flammability of the live plant material create ideal conditions for a fast spreading, high intensity, crown fire (Howard, 1993).

The fire frequency and season of burn may affect the species composition. Shorter fire returns intervals of 30 to 40 years may favor hoaryleaf ceanothus, while longer intervals of 100 years or more favor the longer lived chamise. Fires in spring and summer have a higher mortality rate for chamise than in fall. This is because the carbohydrate storage in the lignotuber has been depleted due to the spring growth, and there is insufficient energy to send up new shoots. The carbohydrates are replenished during the summer, replenishing the carbohydrate storage by fall (McMurray, 1990). Some studies suggest that fires used to be in the summer months and would burn slowly in relatively small areas. Only occasionally would these fires last until fall and be fanned by the Santa Anna winds, which cause the fires to race across the mountains burning thousands of hectares a day (Keeley and Fotheringham, 2001).

When fire does occur in this chaparral community, it usually burns the canopy of the entire stand, creating transition, T1.1a which leads to stand regeneration.

State 4
Young chaparral 1.3

Community 4.1
Young chaparral 1.3

This community is a young chamise and hoaryleaf ceanothus chaparral community still in the growth phase following a fire. The young shrubs are beginning to shade out the understory and are beginning the self thinning process.

The primary pathway for this community is 1.3a to continue with the growth and development of the shrub species. This phase may last from 2 to 30 years, before regaining its potential cover and composition.

If fire burns this community during this stage (initiating pathway 1.3b) it will return to the regeneration phase.

State 5
Degraded chaparral State 2

Community 5.1
Degraded chaparral State 2

This state develops with an altered fire regime and/or with the introduction of non-native plant species. Increased fire frequencies and low intensity fires can be detrimental to chaparral regeneration. This altered state has similar plant communities to the reference state, but native subshrubs such as black sage (Salvia mellifera) and Eastern Mojave buckwheat (Eriogonum fasciculatum) may have increased in cover and non-native species such as oats (Avena spp.) and bromes (Bromus spp.) are present. The overall cover of the chaparral and woodland species has declined, with more openings in the canopy. It is difficult to determine the effect on the chaparral species composition during this state, but some species may be better adapted to shorter fire intervals than others.
The non-native species become established after a fire or other disturbances such as road building, grazing, or foot traffic. The non-native grasses can alter the fire regime by creating an easily flammable and continuous fuel source. When the fire frequency increases this state may loose the chaparral species and transition to state 3 (T2a).

Once the non-native species become established it is extremely difficult to eliminate them from the area. Restoration efforts should focus on eliminating non-native species, and if possible keep the fire return interval to greater than 70 years (R2a).

State 6
Non-native grassland State 3

Community 6.1
Non-native grassland State 3

When fire repeatedly burns through a chaparral community, before the species reach maturity, the presence of the chaparral species may decline. Since most of the dormant seeds in the seed bank germinate the first year after a fire, there are very few seeds left to germinate after subsequent fires. Time without disturbance is needed for the shrubs to mature and produce seeds. Frequent fires also affect the ability for the resprouting shrubs to send up new shoots by depleting the carbohydrate storage in the root systems. In the absence of shrub seedlings and resprouting lignotubers, non-native annual grasses become dominate and self-perpetuate the frequent fire cycle. The time interval needed for the chaparral species to recover and produce enough seed for sufficient regeneration after a fire is variable. Some reports say that a 20 to 40 year fire free interval may be too short.
Non-native species listed by Dagit are the common non-native grasses (Avena fatua, Bromus sp., Cynodon dactylon, Festuca sp., Hordeum murinum, etc.) and mustard (Brassica nigra), followed by a variety of thistles (Centaurea melitensis, Salsola iberica, etc.).

Once the non-native species become established and the chaparral species have been eliminated it is extremely difficult to restore this area. Restoration efforts should focus on reintroducing native species, eliminating non-native species, and reducing the fire frequency (R2a).