Pacific Mountain System Coast Ranges

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Pacific Mountain SystemCoast Ranges
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North Coastal Ranges
South Coastal Ranges
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Coast ranges

• Most Mountain peaks at around 4,000 ft.
• 550 miles long (North South)
• Divided into Northern and Southern Ranges at San
  Francisco Bay
• Proximity to ocean on west slope, keeps
  temperatures cool, and fog common
• Fog held there by mountains.
• Inland valleys, peaks have less coastal
  influences

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North Coast Ranges

• Run north of SF to Klamath Mountains, by Eureka.
• Heavy summer fog keeps soil moist along coast
• Adds up 10 inches of precipitation
• Inland valleys drier due to rainshadow
• Bodega, Napa, Sonoma etc.
• Heavy Salt spray along coast
• Include mostly North/South running river valleys
• Eel,
• Except Russian River east - west
• Older than Southern Ranges.
• Includes higher peaks, some exceeding 7,000 ft.

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North Coast Ranges

• Most Seismically active region in United States
• In the 1990s, at least nine magnitude 6.0-plus
  earthquakes jolted the North Coast. This amount
  of large quakes was higher than in any other
  decade within the last century.
• Tsunami threat very high

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Uplifting

• West coast constant rising up over last several
  million years.
• Along with changes in sea level during Ice Ages
  the uplifting of old marine / shoreline terraces
  are moved from 100 - 1000 ft. above sea level.
• Sedimentary layers get tilted in uplifting and
  when saturated they may give way, causing the
  frequent mudslides along southern coast.

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Eroded Marine Terraces Montaña de Oro State Park
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North Coast Marine Terraces
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Northern Coastal Zones

• Rocky intertidal ocean and land meet- high
  diversity of algae and animals.
• Dunes (strand) drought adapted vegetation.
• Vines, deep roots, shifting sands
• Coastal Prairie first terrace, uplifted dune
• Green year round, perennial wildflowers, rushes,
  etc. Used for pasture for Dairy cows
• Redwood forest cool wet areas away from salt
  spray

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Northern Coastal Zones

• Pygmy forest shallow soil with hard pan
  underneath in sandstone.
• Water logged in winter, drier in summer
• Costal fog keeps trees alive in summer
• Restricted root growth stunts plants
• Bolander Pine endemic species, Pygmy cypress
  grows there as poor competitor.
• Closed Cone pines on uplifted dunes- sandy soils,
  cool wet climate with fog.

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Pygmy Forest

• Shallow soil
• Hardpan layer restrict root growth
• Small plants but old with mature cones, berries
• Needs heavy summer fog to prevent drying out

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Northern Coastal Zones

• Mixed evergreen forest
• Douglas fir, Tanoak, Giant Chinquapin, Madrone,
  Bay, Coast Live Oak
• Yellow Pine- Jeffery Pine
• High elevation or dry with serpentine
• Foothill woodland
• Blue oak inland, Oregon oak in coastal slopes
• Foothill pine, Buckeye, Redbud,
• Coast / Interior Live on north slopes
• Riparian
• Redwood, Bay, BL Maple, Doug fir, Torreya,
  Dogwood, Alder , Willow

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Biotic Zonation of North Coast Ranges
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North Coast Range Geology

• Arc islands that got accreted to North American
  plate during the late Mesozoic (65-150 million
  years ago).
• Has Franciscan rocks (shales and sandstones)
  formed by rapid erosion settling into marine
  basins then uplifted as arc islands.

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• Franciscan Rocks sedimentary marine deposits
  uplifted
• Salinian Block formed south of Sierras, moved
  North 190 miles.
• Population of salamanders, newts traveled along
  with rocks
• Now isolated separate species

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Southern Coast Ranges

• Run from SF to Transverse Ranges, by Santa
  Barbara
• Some peaks reach 6,000 ft. Taller peaks in the
  southern end due to less erosion
• Large wider North South valleys
• Salinas River Valley
• Nacimiento River Valley
• Strong slope effect south facing dry,
  chaparral, north has evergreen oaks

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South Coast Range Geology

• The Granitic rocks in the core formed as part of
  Sierra Nevada batholiths moved north up to 300
  miles north by San Andreas fault activity over
  last 25 million years.
• Uplifting and placement of Southern Coast Ranges
  above sea level over last 1-2 million years, much
  more recent then Northern Ranges.
• Mainly composed of soft unstable sedimentary
  rocks easily eroded
• Santa Cruz cliffs loose an average of a foot a
  year.
• Maximum record was 75 feet in one storm season

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Coastal erosion
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Serpentine - an Edaphic (soil) ecological island

• Igneous rocks intruded into Franciscam rocks and
  metamorphosized by heat and sea water to green
  serpentine.
• named for serpent pattern of mottled snake skin.
• rich in Mg and Fe Ni, Co, Cr
• low in Ca Na, K
• make root function difficult for plants, water
  stress
• Exclude annual grasses

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Serpentine communities

• Poor competitors survive on serpentine
• In North Coast ranges chaparral with Chamise
• In wetter areas Closed Cone Pines, Jeffery Pine
  or Incense Cedar predominate
• Specialists plants adapted to serpentine
• Leather oak
• Interior Silktassel
• Shrubby forms of California bay
• Macnab Cypress in interior North Coast ranges

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Serpentine areas in California
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Banana Slug- Our State Mollusk
Very common in moist Coastal forests
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Monarch Butterflies

• West of Rockies, Adults over-winter in coastal
  valleys from Bolinas, to Ensenada.
• Eastern Monarchs migrate to central Mexico.
• Only known insect that migrates over long
  distances.
• 3000 miles to MX
• 660 miles AZ to CA

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Winters

• Adults eat nectar- hard to find in winter inland,
  easier along coast, Mexico
• Adults migrate, basically going extinct in cold
  areas over the winter.
• Return to same trees as the previous year. Yet
  They are three or four generations removed from
  previous years monarchs!!
• Migration is instinctive, not learned
• In spring they repopulate, laying eggs as they
  fly back north, west. Offspring then take over
  repopulation spreading the population back as
  winter retreats.

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Migration Routes
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Monarchs protected by Milkweed toxins eaten while
larvae
Larvae (caterpillars) eat Milkweed, and
accumulate the toxic cardiac glycosides. The
Monarchs are immune but their predators are
not. Monarchs are protected by these compounds
from being eaten in general. A few must be lost
so birds learn to avoid them. Predators (birds)
learn to avoid adult monarchs by their coloration.