Transcript Coast Conifers - Diablo Valley College

Coast Range Conifers
Coast Redwoods and
Closed Cone Pines
Redwoods
• 3 Relict species left from when climate
was cooler and wetter.
– now trapped in refuges where there are
remnants of former climate
• Coast Redwood- Redwood lumber
– Sequoia sempervirens
• Sierra Big Tree, “Giant Sequoia”
– Sequoiadendron giganteum
• Dawn Redwood- (Now only in China)
– Metasequoia glyptostroboides
• Great web site: http://www.nearctica.com
Sierra Big Trees
Metasequoia
• Once common in North America
• Only 5000 are left in the wild in a small
area between the Sichuan and Hubei
provinces in China
•
A Deciduous conifer
Coast
Redwood
Forest
• In narrow 14
mile belt just
inland from
coast,
• from southern
Oregon to
Big Sur
Coast Redwood
• Needs cool summer weather, with fog to
stay wet.
• Does not tolerate long freezing
temperature
• Can not tolerate salt spry (dries out
leaves) – grows one hill back from coast
• Stump sprouts from cut trees forming
circle of new trees “Fairy Ring” –
genetically identical to fallen log
Coast Redwood trees
• Open Coned trees, but needs sterile (recently
burned) soil for seeds to grow , or they succumb
to fungal diseases.
• Needs full sunlight, drops branches that are
shaded.
• Closed canopy forest dark understory that
excludes other species, often a monoculture
• thick needle “duff”’ layer covers soil
• Bark resistant to fire, trunk can regrow branches
that burn
• Sprouts new roots at trunk base after floods
• Roots graft together into a large network
Coast Redwood Forest
• Dark damp understory
• Ferns, Marbled Murret, Sorrel, Oxalis, Azalea,
Huckleberry, snowberry, etc
• Have large flat water needy leaves
• Little wind in understory so plants there use
animals for pollination & seed dispersal
• Most form berries for animals to disperse seeds.
• Trillium, and Viola form oily Elaiosomes on small
seeds. Ants eat oil while carrying seeds and
discard, dispersing seeds.
Old Growth Redwood
Forests
• “Virgin” forest never cut down.
• Many Trees thousands of years old.
• Only in old growth forests are all of the
following characteristics present:
– Large living trees and a multi-layered canopy
– Large standing snags
– Large down trees
– Large fallen trees in streams
“Virgin” Old Growth forests, 1620
“Virgin” Old Growth forests, 1998
Felling The Redwoods
Redwood Lumber
• Heartwood very resistant to decay.
• Used for earl development in California
• Many communities started as lumber
villages around saw mills.
• Still used for outdoor furniture, fences,
decks,etc.
• New lumber mostly younger secondary
growth has little resistant heart wood,
needs to treated to resist decay.
• Can be harvested every 40 years.
Beginnings of Redwood Conservation
• Sempervirens Fund
started in 1900 to
preserve trees in
Santa Cruz Mountains
• They pushed for making
Big Basin State Park
(1902) with its Redwoods
Save The Redwoods League - formed in 1918
to save some of the remaining Old Growth
Forests Both groups still very active
Timber cut (billions of board feet)
14
12
10
8
6
4
2
0
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
Fig. 23.14a, p. 601
Annual recreational visits (millions)
350
300
250
200
150
100
50
0
1930
1940
1950
1960
1970
Year
1980
1990
2000
2010
Fig. 23.14b, p. 601
Some Important Parks
• Muir Woods, Marin County
• Armstrong Redwoods State Park,
Guerneville
• Redwood National Park
• Big Sur State Park
• Big Basin State Park
Douglas Fir
• Most
common
timber tree
in the west
• Found
associated
with many
other trees
Sustainable Harvest
• Using a select cut, trees may be harvest from
same site every 10-20 years indefinitely.
– Set up permanent, well design roads
– Remove only a few trees each round
– Remaining trees get more light and grow faster.
• Many timber companies use clear cut
– More economical
– Size of are important, small (1-2 acre areas)
considered safe method. Large areas have problems.
– Tress stump sprout
– If small area, fog is enough to allow for recovery with
out drying out.
Selective Cutting
Clear-Cutting
30-40 yrs
Cut
Cut
Cut
3–5 years ago 1 year ago
10-20 years ago
Strip Cutting – small clear cut areas
40 plus yrs.
North Coast Marine Terraces
Upper Terrace In Big Basin
Closed Cone Pines
• Fire adapted- fire opens cones.
– Most will open when old, if fire doesn’t happen
– Knob cone the most closed- needs fire to
open
• Most of the forest is same-age trees dating
to last major fire
• Point Reyes: Bishop Pine Forest died in
last big natural fire started in October 1995
• Test plots set up to study rejuvenation
• http://plantbio.berkeley.edu/~bruns/postfire-bp.html
Point Reyes 1995 Fire & 3 years after
Smoke
plume from
fire
Relicts of earlier climate
• 225-65 MYA (Million Years Ago) most of South
Coast Range and Central Valley a shallow sea.
• Followed by a temperate (cool) rain forest
• 15 MYA climate gets colder and drier, drought
adapted conifers move in from Idaho area
• Ice Age, and Sierras uplift, climate continues to
get drier
• These trees are remnant populations trapped in
pockets along cost with the cool, moist climate.
Poor competitors use areas unsuitable for other
wet area trees – sandy and serpentine soils.
• Once may all have been one species, now
separated and adapted to local areas
Bishop Pine
Knob Cone Pine
Monterey Pine
Monterey Cypress