California Chaparral

and Coastal Sage Scrub

Chaparral: Communities of evergreen sclerophyll shrubs that develop where Mediterranean climates prevail

– Warm-temperate

– Cool, moist winters

– Hot, dry summers

– 80% of rain falls in winter

Chaparral, maquis, garigue

Found adjacent to, and inland from coast

Plants possess unifying adaptations:

– Dense crowns

– Sclerophylls

– Wide spreading root systems

– Adapted to fire

• Heat scarified seeds

• Sprouting from root crowns

Californian Coastal Scrub:

– Occurs below chaparral

– More xeric, short-shrub community

– Referred to as “soft chaparral”

– Very dry climate (12 in/y) ameliorated by coastal location

• Cooler

• Fog and overcast

• Where not on coast, this would be desert scrub

Chaparral species

– Adenostoma fasciculatum

– Arctostaphylos auriculata

– A. glandulosa

– A. glauca

– A. pajaroensis

– Ceanothus cuneatus

– C. greggii

– C. megacarpus

– C. spinosus

– Cercocarpus betuloides

– Heteromeles arbutifolia

– Quercus dumosa

Coastal Scrub Sage species

• All of the sub-shrubs and suffrutescent species of the chaparral, plus:

– Encelia californica

– Baccharis pilularis

– Viguera laciniata

– Lepidospartum squamatum

• Aromatic dominants:

– Artemisia californica

– Salvia mellifera

– Salvia leucophylla

• Most dominants are shallow-rooted sub-shrubs that lose their foliage in response to drought.

• When water is available, they can grow twice as fast as chaparral species.

Fire

• Wildfires are a dominant part of the environment.

• Frequency averages once every two to three decades in natural systems.

• More in human dominated systems.

• Fires are big (thousands of hectares).

Fire Response

• Chaparral

– Herbaceous and suffrutescent species grow back abundantly after fire.

– Shrubs grow back after four years from seeds or sprouting

• Coastal scrub

– Plants resprout and flower first year

– Seed crops result in a huge seedling recruitment in the second year.

Restoration

• Wilkins, K. 2009

– Chaparral species planted into a closed quarry

– Fire enhances germination, post-fire.

– Fire, heat and char were used.

– Best treatment was Wright’s Liquid Smoke and heat.

– Increased germination of Adenostoma fasciculatum, Ceanothus cuneatus and Salvia mellifera.

• Cione, Padgett and Allen, 2002

– Restored fragment of coastal sage scrub in urban environment.

– Site had been subjected to fire, anthropogenic nitrogen deposition and invasion by Mediterranean annual weeds.

– Hand cultivation and grass-specific herbicides successfully controlled weeds.

– Seeds were sown to replace depleted seedbank

– Seeding succeeded in a wet year but not a dry year.

– Green yardwaste mulch did not help

– Shrubs began to exclude grasses by second year.

• Stratton, 2004

– Planting and seeding into abandoned ag fields on Santa Catalina Island

– Problems: weeds, deer bison

– Annual weed control, seeding and planting seedlings without protection were inadequate

– Seedlings planted into wood chips were easy to see and were browsed.

– Watering helped in dry years.

– Use of native soil and oak litter increased acorn establishment.

• Burkhart 2006

– Deep one gallon containers showed much greater survival than liners or regular one gallon pots.

– Species used were deep-taprooted species including Quercus agrifolia.

– Growth surpasses five gallon pots, and planting is much easier and with lower production costs.

• Allen et al. 2000

– Coastal sage is becoming difficult to restore

• Weeds, frequent fire, nitrogen deposition

– Native shrub re-colonization is slow where Mediterranean annual grasses are present.

• Bromus, Avena, Vulpia, Hordeum

– Other weeds: Cynara, Carpobrotus, Chrysanthemum, Brassica, Erodium, Centauria, Feniculum, Nicotiana

– Shrub restoration from seed not successful unless grasses are removed.

– Seedlings of Artemisia californica succeeded; survival and growth rate were increased by weeding.

– Anthropogenic nitrogen deposition from automobile exhaust favors weeds.

– A regional strategy will select sites that are most likely to respond to restoration favorably.

• Bowler, 2000

– Standard mitigation practice: nursery grown container plants (shrubs), plus hydroseeding or imprinted seeding.

– “Doomed” sites can be harvested

• Seed sources

• Seedling collection

• Mature adult shrubs

• Soil

– Restoration site values:

• Seed sources…transplanted shrubs produce copious seeds crops

• Seed crops produce lots of seedlings which may be harvested before they self-thin.

• Instant habitat

– Landscape mosaic of an intact community was used to design the restoration.

• CSS is patchy, not continuous

– Within restoration mosaic, patches of salvaged mature shrubs are placed within a matrix of imprinted seeding or containerized seedlings.

– This allows early use by bird species and results in faster expansion of CSS.

– Transplanted shrubs are removed from donor site and placed in restoration site during winter rainy season.

• No additional watering is needed

• Keeley 2002

– Fire management in California shrublands is influenced by policies for coniferous forests.

• It has not effectively excluded fire

• Catastrophic wildfires are not the result of unnatural fuel accumulation

– There is no evidence that prescribed burning has any resource benefit.

– Therefore, fire hazard reduction is the primary benefit

– Rotational burning to create a landscape mosaic is not a cost-effective way to control wildfires.

– High fire frequency can extirpate species sensitive to short fire return intervals.

– Some shrub communities have successfully weathered century long fire-free periods.

– There are no examples where fire dependent shrublands are threatened by lack of fire.

– The most cost-effective strategy for limiting catastrophic fires is buffer zone management.

• Intensive management at the urban-wildland interface.

• Buffer zones 1) prevent wildland fires from entering urban areas, and 2) limit ignitions arising from urban populations

• Buffer zone types

– Rotational burning to create younger age classes

– Conversion to less hazardous fuel types (harvest)

– Green belts

– Denuded zone