Transcript Chaparral - Diablo Valley College

Chaparral -
Chaparral
around the
globe
Chaparral
• from Spanish word for el chaparro, shrubby
evergreen oaks in Spain.
• Gave name to chaps, leg protectors to riding
horse back through this tough vegetation
type.
• Covers about 8 % of the state.
• Found in drier sites (south slopes) on
western slope of Sierras, along Coastal
Ranges
• Found On dry or nutrient poor soils
• Common on serpentine as well.
• Associated with Mediterranean
climates.
• Often evergreen shrubs with small
tough (sclerophyllous) leaves.
• Often with resinous or waxy coverings.
• Very dry in summer, leading to fires.
Resinous & waxy coverings
• Odor of flowers attract pollinators
• Odor in foliage indicates compounds
that deter herbivory.
• waxy or oily covering may also protect
from desiccation
• Makes easy for it to combust
Root systems
• Two-tiered root systems, absorb water longer
into the season.
– Shallow roots to get rains, fast spring growth
– Deep roots for water late in the season
• Nitrogen fixing bacteria in roots common.
– help after nitrogen loss in fires.
• Mycorrhizae fungi associated with roots, that
help obtain nutrients and water.
– Most of the mushrooms in the forest, e.g.
Chanterelles.
Growth cycle
• Sierra Chaparral flushes out later that
coastal chaparral, but grows for longer
time.
• Lower photosynthetic rate than drought
deciduous, but can grow all season.
• Above ground growth in wetter months,
root growth mostly in summer.
Fire Cycle
• Community most likely to burn in many areas.
• Many homes now built in these areas.
• Early succession after fire, nutrient limited, mostly
annuals and forbs (herbs) wildflowers.
• Many species are sprouters– Burl survives fire, seeds out new shoots afterwards
• new growth may be very high in protein 14%, deer and
other animals rely on this growth.
• some closed cone pines - need fire to release seeds.
• Fire follower annual- seeds in soil seed bank
germinate and predominate first few years after fire
• Shrub canopy closes in about 6 years
Fire poppies in burn area
Madrons sprouts from burl
Ceanothus seedlings sprout after fire
1 month
post fire
Schmidts, M.J., D.A.
Sims,
J.A. Gamon
California State
University,
Los Angeles, CA
http://vcsars.calstatela.edu/eas_00/miriam/miriam_esa_00.html
First spring 3 years post fire
20
and 40 years post fire
Old fires
• Before fires limited by suppression:
• Had a patch-work mosaic of previously
burned areas, smaller areas available to burn
each time
– now with suppression large areas burn very hot.
– Now they can kill burrowing animals and much
more severe erosion in the fall rains.
• Old records some long-lasting (months) slowmoving smouldering fires, similar to the
Sierras.
• Large oaks have a thick non-resinous bark,
fire proof, to former low fires.
Frequent fires lead to a mosaic of
different stand ages in Southern California
chaparral vegetation
Mosaic of ages burns
Soils
• High erosion rates.
– Often on steep slopes, sandy soils.
• Accumulate hydrophobic waxes and oils
(resins) they prevent them from taking
up moisture.
• Hot fires moves these chemicals down
deeper and forms and non-wettable
layer below. Wet upper layer washes
off.
Two of the several different
types of Chaparral in
California
• Maritime Chaparral
– Along the north coast- Bodega Bay
– Similar to Briones
• Warm Chaparral
– Similar to Mt. Diablo, and Sierra foothills on the
way to Yosemite
Maritime Chaparral
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also known as Coastal Scrub
Similar to plants in Briones, Bodega bay
have bendable, or soft flexible leaves.
most are odoriferous and drought tolerant
shrubs.
low growing, knee high
influenced by summer fog, cool winters, little
frost.
shallow root systems that can quickly absorb
fog drip.
dry, 10 inches or less of precipitation per year.
• South Slopes have small leaves and drought
deciduous
– Ca Sagebrush, Artemisia an indicator species.
• finely divide leaves, flush out new growth with winter
rains.
– Bush monkey flowers - seasonal leaf dimorphism
• flush with many leaves in winter.
• Only very small terminal leaves remain alive in dry
months.
• North Slopes- larger shrubs, small trees with
large leaves and deep root systems.
– Toyon. Poison oak, Coyote bush.
• Northern Coastal Scrub - as by BodegaBay
– Coyote bush, Salal, Yerba Santa and Yellow Bush
Lupine.
– Very near coast and mixed with coastal prairies.
Maritime ( soft) chaparral
North Coast chaparral
Warm Chaparral
Warm chaparral
• on lower slopes of mountains,
• below snow line; is frost tolerant, but not
snow tolerant.
• Most are evergreen with waxy or resinous
coverings, not drought deciduous.
• Strong north - South slope effect, large/small
leaves
• Sclerophyllous (very tough, rigid leaves).
– Long lived and well protected leaves.
– Stiff leaves, with non digestible fibers, protect from
herbivores
– reduce water loss
Chamise (Adnostema)
• Most common in southern ranges and
Southern ca.
• Very small, needle like drought adapted
leaves.
• Well adapted to sprouting after fires.
• Has both fire and non fire seeds.
• Can reestablish by seeds after a hot fire that
kills the burl.
• At high temperatures, chamise emits
flammable gasses that ignite, and spread the
fire.
Chamise
Chamisal
Ceanothus spp.
• Common genus in California, many different
species.
• Recognizable usually by three main veins on
underside of leaf
• Early successional species.
• They do not sprout, need to seed in after
fires.
• Warm soils stimulate seeds dormant in seed
bank to grow.
• Many have nitrogen-fixing bacteria that help
replenish the scorched soils.
• Import deer food – e.g. Buck brush
CeanothusCalifornia Lilac
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