Download 417_biogeography

Geography 417
California for Educators
Lesson One
California’s Biogeography
Plants and Animals
• Why is this important?
– Conditions that encourage or prevent native plants and animals
offer a blueprint for what can be done agriculturally in the state.
– Many of the cues given to us are not heeded and ecological
problems can result.
– California has some of the greatest natural diversity in the world.
Preliminary Definitions
• Ecology: The study of interactions between life-forms and their environment
• Ecosystem: a total assemblage of components living and non living that
compose the interactive sphere of a group of organisms
• Biome: the largest category of ecosystem, perhaps stretching over half a
continent
More Definitions
• Biogeography: the study of the variation in ecosystems from place to place.
• The distributions of biomes and ecosystems is largely a factor of conditions
of heat, moisture and topography (all condition soil chemistry).
• The characteristics of biomes are largely a factor of climate, so it is
important that you integrate knowledge from last chapter.
Habitats
• A habitat is the home environment most typical for a given species.
• Habitats are characterized by special soil, topographic, light and heat
conditions.
• Various habitats are possible in a small geographic space.
• Each plant/animal may occupy a certain place/niche in a habitat, sometimes
exclusive to that species.
Habitat (cont’)
• A group of organisms that live together is called a community and
these communities often assemble themselves in predictable
patterns called associations (Hickory-Oak).
• A biome is a very large associative community.
Habitats (fig)
The Foo d W e b
• Energy is transferred through an ecosystem network called the food web or
food chain.
• Plants and algae, because they are at the bottom of the food chain are
known as primary producers.
• Primary producers convert sun energy into carbohydrates through a
process known as photosynthesis.
F o o d W e b (c o n t’ )
• With each transfer of sun energy through the food web, energy is
lost in a process called respiration.
• An enormous amount of energy, originally in the system is lost
with each move up the chain (can be 10-50% each link).
• Wasted energy is mostly lost as heat and cannot be recovered by
ot h e r s p e c i e s .
• Requires that producers be most numerous and consumers be
fewest in a food chain.
Energy Loss up the Food Chain (fig)
Biomass
• Biomass is a measure of plant and animal matter frequently used to
characterize the basic nature of an ecosystem.
• Measured as the dry weight of all the organic matter in a given unit of
space.
• Forests have the most biomass, mostly because trees get so big.
• Some systems lose a great deal of biomass annually to consumers and
decomposers
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What Factors Contribute to the Creation of Biomes /
Communities?
Water Availability
Heat and Cold
Slope and Aspect
Soil Chemistry
Other plants and animals
Water Need
• Xerophytes are plants that are adapted to insufficient water conditions
• They include plants that live in dry climate but also plants that grow in well
drained soils.
• Many have thick (storage), waxy leaves that reduce transpiration or no
leaves at all.
• Some xerophytes have deep roots, others have extensive but shallow roots.
• Many xerophytes have irregular life-cycles or dormancy periods during extra
dry times.
California Precipitation
Tropophytes
• Plants that respond to seasonal patterns in moisture availability by
dropping leaves and going dormant.
• Deciduous trees are good examples, but grasses also have
dormancy periods.
Sclerophylls
• Characterize the woody plants with thick leathery leaves that are
well adapted to drought conditions
• The Live Oak is such a plant.
• Some are “evergreen broadleaf” trees because they do not drop
their leaves during a dry season, but retain them in case moisture
returns.
• Common in California
Xeric Animals
• A variety of adaptive strategies have evolved in animals living in
dr y c l i m a t e s .
• In addition to the brine shrimp, what are some others?
Climatic Variance in CA
• Availability of water (drought/freeze)
(2” - 80”+)
– Relative Humidity
• Length of Growing Season (5 weeks - 365 days)
– from last spring freeze to 1st winter freeze
California Temperature
Organisms and Temperature
• Temperature regulates a number of the functions of plants and animals as
well.
• Temperature helps organisms know when to mate, enter metamorphosis,
shed leaves, etc.
• Temperature also indirectly affects plants by regulating evaporation and
transpiration rates and by affecting soil characteristics.
• Deciduous/Evergreen Behavior
– cold, low sun, or drought
Temperature (cont’)
• Many plants cannot survive freezing temperatures.
• Cold blooded animals have no internal mechanism for regulating
temperature so must use the environment to do so. Many must migrate or
become dormant during cold weather.
• Hibernating animals use the constancy of soil temperatures to help them
survive during a dormant period in cold weather.
• Warm blooded animals have a variety of mechanisms for regulating
temperatures and can survive in a broader range of climates.
Other Climate Factors
• Intensity of light and duration of light are other important factors regulating
plant life.
• Some plants adapt to shade by growing very large leafs, others grow to
heights not reached by other plants.
• Photo period (length of day) helps plants know when to engage in various
processes.
• Wind is another physical process that organisms use to determine
appropriate “behavior”.
Altitudinal Zonation
• Changes in altitude create changes in temperature and moisture
which in turn create differences in vegetative cover.
• figure
Vertical Zonation of Vegetation
Geomorphic Factors
• How steep a hillside is and which direction it faces can affect the
prevalence of a species.
• (slope and aspect)
• Can you think of examples?
Edaphic (Soil) Factors
• Soil characteristics, like how much sand or clay is in it, affects
what type of plants can grow in a place (nutrient content, moisture
content) and in turn may affect what sort of animals reside there.
Bioclimatic Frontier
• By using a variety of measures, we can frequently figure out the
physical boundaries, or limits of a species range.
• Can you think of a plant or animal which you are familiar with its
frontier?
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Interactions Among Species
Species may live together in a variety of arrangements.
Species may compete for scarce resources.
One may predate (eat) another.
One might live off another (parasite)
– Is predation and parasitism always bad?
More Interactions
• Alleopathy is the production of poisons that reduce competition by
nearby plants.
– Common among some desert plants
• Symbiosis is??
– Commensalism: epiphytes
– Protocooperation-not necessary but helpful
– Mutualism-each party needs the other
Ecological Succession
• Ecosystems often go through stages (seres) of development,
culminating with a stable arrangement of organisms called a
climax community.
• Explains the process whereby a field cleared by humans or fire
will eventually return to “natural” state.
• Other landscape items also engage in succession.
Succession (cont’)
• After a disturbance, the first group of organisms to emerge are
called pioneers.
• Pioneers are mostly annual weeds, but they provide important
shade and nutrients to the soil.
• Weeds give way to taller grasses and woody shrubs, which in turn
give way to pine trees and eventually (in some cases) to
hardwoods.
Succession (cont’)
• Climax forests are often susceptible to fires, disease or pest
invasions which in turn renew the process.
• Some forests need fire for regeneration.
• Along with the slow changes in plant life, animal life changes in
response to the prevailing vegetative patterns.
Ecological Succession
Natural Vegetation
• Natural Vegetation is what you might find in a place if humans had
not interfered with the natural succession.
• Only in a few biomes is the natural regime still largely in tact.
• Few areas in the midlatitudes are natural
• Exotic plants also alter the natural vegetation pattern
• What is “natural” up for debate.
California Vegetation Zones (fig)
California Forests (fig)
California Landcover
(fig)
Terrestrial Ecosystems: Biomes
• Great ecosystems of the world that include generally (and
with sub-categories called formation classes):
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Forests
Savanna
Grassland
Desert
Tundra
Natural Vegetation of
the World West (map)
Calif. “Biomes”
Needleleaf/Coastal forests
Chaparral and Coastal Shrublands
Oak Mixed Woodlands
Short grass prairie
Semi desert
Desert scrub
The Littoral
Biomes and California
Biomes may be inappropriate to the study of biogeography in
California because the immense variation in ecosystems in
this relatively small territory and because biomes are too
large to capture some of the great variance within California’s
biomes.
Coastal Sand Ecosystems
Includes both the littoral strand (beach) and dunes region.
Temperature
Soil (nutrient, drainage)
Salinity
Humans
Introduced species
May support several species of trees, marsh
The Littoral
• More than 1,000 miles of coastline, much of it still largely intact as a result of
environmental law and the California Coastal Act of 1976.
• Coastal Lagoons and Marshes - stops on the Pacific flyway for migrating birds. More
than 90% have been destroyed.
• Environmental Issues: Much of SoCal littoral has been dramatically modified and
developed.
• Sea Otters - 16,000 200 hundred years ago. By 1900, hunted to virtual extinction. Today
there are roughly 1,500.
• Fisheries - Monterey’s Cannery Row (sardines), Various tuna fisheries may be
threatened.
• Offshore Drilling - Santa Barbara Channel oil spill of 1968.
El Segundo Blue Butterfly (fig)
Scrub Forests
• Dryland and Desert “forests”
• Several types in California
Coastal Scrub
• “Soft chaparral, coastal sage”
• Common in coastal areas below 2500 ft, so they share habitat
with ?
• Thin band along coast in north, more widespread in south;
Climates range from moist to near desert
• Many pyrophytic species
Northern Coastal Scrub
 Mainly low elevation near coast
 Often found on old stabilized dunes
Southern coastal sage scrub
 Medium-sized or small drought deciduous shrubs, with grayish-green leaves.
Often these plants are aromatic with a sage-like or minty odor
 Formerly widespread in coastal southern California
 Grows in dry coastal areas with moderate temperatures
 Referred to as soft chaparral or sage scrub
Chaparral
• Covers 10% of the state
• Climate, soil conditions make it more common in Southern
CA.
• Pyrophytic and famous
• Controlled burning
• Manzanita
• Toyon and Hollywood
• Animals of the chaparral? Bears?
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Chaparral
Widespread throughout California
Occupy low dry slopes in north, cover much of southern mountains
Known as hard chaparral - woody shrubs 10-15 ft high
Common species include chamise, ceanothus, manzanita
Many species fire adapted - root sprout, volatile oils (Manzanita)
Sclerophyll Forest
• We know this as chaparral shrub forest
• Composed exclusively of short, drought resistant trees with tough
leaves and thick bark and low branches.
• Mostly really woodland and dominated by shrubs and grasses called a
scrub forest.
• Only found in California in the US, but in many Mediterranean regions
and Australia.
• Chaparral or dwarf forest in CA
Sclerophyll Forests (map)
Sclerophyll Forests (map)
Chaparral (fig)
Chamise (fig)
Manzanita (fig)
California Lilac (fig)
Northern Coastal Scrub Communities (figs)
Southern Coastal Scrub Communities (figs)
Coastal Sage Scrub (figs)
Laurel sumac (Malosma laurina), California sagebrush (Artemisia californica), White
sage (Salvia apiana) in Diegan Coastal Sage Scrub
Desert Biome
• Semi-desert is drier than steppe and has little grass, but many tough
little xerophytic plants such as sagebrush.
• In the tropics similar climates produce great thorn tree deserts.
• Some deserts have very specially adapted plants like the cactus or
desert flowers.
• Some deserts have virtually no plant life.
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Deserts West (map)
Deserts West (map)
High Deserts
Significant seasonal and diurnal swings
Evapotranspiration exceeds the 10in rain
Poor soils
Piñon Pine and Juniper grow in higher elevations where soil/moisture
are better
• Joshua Trees are indicative of the Mojave or high desert.
Desert Survival Strategies
Xerophytic Adaptations
 Schlerophyllous adaptations - small, waxy leaves or thorns replace leaves
 Succulents - stems modified to spongy water storage structures
 Ephemerals (obligate seeders) - fast reproductive cycle
 Deep tap roots - connect to perennial water.
 Wide spacing with shallow roots - collect sparse rainfall
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Great Basin Sagebrush
Dry areas with cold winters
Mainly found east of Sierra and Cascades and east slopes of Southern
California Mountains
Often overlap with lower elevation range of Pinyon-Juniper
Some sage older than 200 years
Cold, dry climate
Great Basin Sagebrush (fig)
Joshua Tree (fig)
Desert (fig)
Creosote Bush Scrub (fig)
Lower Scrub Deserts
• Cover 30% of the state, mostly in the Southeastern region, but
elsewhere
• Soils, heat, drought, cold
• No trees,
• Sagebrush-scrub-creosote bush
• King Clone= 11,000+ years old.
• Jojoba
• Barrel cactus, cholla, saguaro
• ephemerals
Grassland Biome
• One type is the tall grass prairie that once extended from Illinois to the
middle parts of Kansas, Iowa, Nebraska etc. Great farming.
• Beyond that was short-grass prairie, which has much less vegetative
cover and is created by drier conditions. Also known as steppe and
is often used agriculturally.
• Jumpers, diggers and racers.
Grasslands West (map)
Grasslands West (map)
California’s Grasslands
• Once covered 13% of the state
• Where? Why?
– Precipitation and soil porosity
• What has this region been adapted by humans to function
as ?
• Effect of grazing non-native animals?
Grassland Communities and Marshes
• Formerly covered most of Sacramento, San Joaquin and Salinas
Valleys
• Habitat for as many as 50,000 - 100, 000 Native Americans
• Huge areas of marsh and bunchgrasses - pronghorn antelope, elk,
cougars, & bears
• Areas with moderately low precipitation, hot summers
• Have been modified earlier and more extensively than any other plant
community
• We don't know what native grasslands really like because alien
grasses and grazing animals were introduced early by Spanish
• Mediterranean species well adapted to conditions
Grassland Communities and Marshes (fig)
Forest Biome
• Include six varieties of forest:
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Low Latitude Forest (not in US)
Monsoon Forest (wet-dry CA)
Subtropical Evergreen Forest (not in CA)
Midlatitude Deciduous Forest (CA)
Needleleaf Forest (CA)
Sclerophyll Forest or Scrub Forest (CA)
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See above
Savanna Biome
Found in wet-dry climates.
Few trees, lots of grassland and abundant shrubs.
Multiple species with a variety of adaptive strategies apparent.
Fire resistant and animal resistant.
Many rain-green species that go dormant.
Many grazing species and predators.
Famous in Africa, but common as Oak Woodlands in California
Oak Woodlands
• Sometimes lumped in with Savanna, because these are open forests
mixed with grasslands, wet-dry climates.
• Common on edges of Great Valley
• North slopes or wetter zones uphill or where soil moisture is held
better by soil
• Includes both deciduous and evergreen oaks, some are drought
deciduous
• Produce acorns
• Much of native range destroyed
Oak Woodlands (fig)
Oak Woodlands (fig)
Oak Woodlands (fig)
Mixed Evergreen Forests
• Occupies a zone between dry oak forests and the wetter
needle leaf forests.
• Many are winter deciduous
Needleleaf Forests
• Includes several important forest sub-types in California
• Coniferous (or cone-bearing) Forest is a generally synonymous term
• Needleleaf forest are generally found where conditions are too difficult
for hardwood trees.
• Generally are the most important commercial forests and are therefore
most often controversial.
Needleleaf Forests (map)
Coastal Coniferous Forest Communities
Closed-Cone Conifers
 Cones remain unopened on branches for years
 Occur in widely scattered stands, mainly in coastal mountains - fog
may be important factor
 Distributions more widespread in past
 Include Monterey pine, cypress, bishop pine
 Torrey pine
Coastal Coniferous Forests
• Part of the temperate rainforest famous in Oregon and
Washington
• Cool temperatures, abundant precipitation, high humidity,
soil conditions
• Fog drip?
• Understory, canopy
• Douglas Fir, Coastal Redwood
• Only 10% old growth forest remains
Coast Redwoods
• Tallest trees on earth
• What allows them to grow so high?
 Foggy summers help prevent water loss and drip up to 20” of
precipitation to forest floor.
• What protections have they and other trees do not?
• Why don’t other trees live to be 2000 years old?
• Northern Spotted Owl 1990
Coastal Redwood Forest
 Sequoia sempervirens
 Ancient relict species once much more widespread
 Occur only in areas with mild temperatures and moisture
available year round from Southern Oregon to Monterey
 Mild, wet winters
North Coast Coniferous Forest
 Temperate rain forest
 Southern extension of Pacific Northwest forests
 Very wet, mild temperatures
Coastal Redwoods
Mountain Conifers
• Include a variety of sub-biomes within California
• They are classified generally by altitude, which affects what
other ecologic factors necessary to create a particular
habitat?
Douglas Fir/Giant Sequoia (figs)
Conifers (fig)
Mixed Evergreen Forest Communities
 Contain conifers and broadleaf trees (black oak, aspen)
 Range from moister mountain regions of southern California to drier
slopes in north
Montane Coniferous Forest Communities
 Cover most mid-elevation ranges of west slope of Sierra Nevada and
Cascades, higher Southern California mountains
 Strong elevational gradients in composition
 Giant sequoias endemic to west slope of Sierra Nevada (sequoia
giganteum)
 Fire adapted - bark and seedlings need ash.
 Douglas Fir (Pseudotsuga menziesii) - natural hybrid of firs and pine.
Christmas tree smell. Huge commercial harvest. Oregon state tree.
Lower Montane Forests
• Includes some of the worst soils, poorest rainfall of the mountain
biomes and therefore some of the hardiest trees.
• Ponderosa Pine and Jeffrey Pine.
• Pacific Yew and Cancerous tumors
• Multiple species in California, which is odd for needleleaf forests.
Pinyon-Juniper Woodland
• Widespread in Northeast, east of the Sierra Nevada and higher desert
mountains of Southern California
• Open woodland with abundant bare soil
• Generally range around 4000-8000'
Pinyon-Juniper Woodland (fig)
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Higher Montane Forests
Better moisture, but often rockier, well drained soils predominate
Red Fir on lower slopes
Lodgepole Pine higher up
Quaking Aspens
Subalpine Forests
The highest ecosystem in California
From 6000 ft to the tree line
Flag trees and snow pack height.
Mountain Hemlock may be the most common species, may look like a
shrub
• Bristlecone pines are the oldest trees on earth some are more than
4,600 years old
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Alpine Regions
Above the tree line.
What kind of plants are found here?
What are the limitations to growth in this region?
Similar to where else in the world?
Why are there fewer alpine regions the further south you travel?
Bristlecone Pine (fig)
Tundra Biome
Specially adapted plants form during the summer months
Very little root system and resistant to hard freezes.
Mostly grasses, lichen, mosses etc.
Also found in high elevations
Few animal species but great numbers.
Ecologic Islands
• Frequently small places with special conditions may support radically
different plant/animal communities than nearby neighbors.
• What factors would contribute to this ?
• Serpentine communities
• Riparian communities
• Desert Wash, Oases, Fan Palm
• Halophyte communities
• http://www.cnps.org/gallery/gallery.htm
Fan Palm (fig)
Saltbush Scrub (fig)
Riparian Vegetation
 Widespread along California Rivers and Streams
 Year round water, or at least groundwater
 Sycamore and Cottonwood Trees, Mule Fat
Riparian Vegetation (fig)
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Introduced Species
Eucalyptus
Palm Trees
Tamarisk
Grass
Tumbleweed
• Crayfish
• Horses, Burros
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Threatened or Endangered Southern California Species
133 Federally listed endangered plants
46 Federally listed threatened plants
2
proposed additions
74 Federally listed endangered animals
41 Federally listed threatened plants
6 proposed additions
• Includes: California Condor, 5 salmon species, 3 trout, 5 steelhead, desert tortoise, 3
sea turtles, bald eagle, peregrine falcon, Cali gnatcathcer, Cali condor, Sierra Nevada
red fox, wolverine, sea otter, 7 whales, 2 bighorn sheep, Stellar sea lion, 4 foxes,
Guadalupe fur seal.
California Condor (fig)
Bald Eagles
1972 Endangered Species Act
DDT