Transcript Weather - El Camino College

Global Climate
Classification
and
Vegetation Relationships
Weather vs. Climate
• Weather
– short-term condition of the atmosphere
– days, weeks
– meteorologists
• Climate
– long-term (30 year) average of weather
conditions and extremes
– climatologists
Climate Determinants
• Insolation and Temperature
– latitude, altitude, land-water, ocean
currents, mountain barriers
• Precipitation
– Air pressure (ITCZ and Subtropical
Highs)
– Air mass influences
– Prevailing winds
The Köppen Climate
Classification
• A Tropical (equatorial regions)
• B Deserts (arid, semiarid)
• C Mesothermal (mild winter)
• D Microthermal (boreal, cold winter))
• E Polar (always cold)
• H Highland (mountains, plateaus)
The Köppen Climate
Classification
3 letter system
First letter = temperature
Second letter = precipitation
Third letter = finer shades of temp
Csb = mediterranean
C = middle latitude temps
s = summer dry
b = warm summers (as opposed to hot [a])
Reading a Climograph
Climate Regions
Koppen’s Categories
Vegetation Regions
Tropical Climates (A)
Tropical Humid Climates (Af)
•
•
•
•
•
1/3 of Earth’s total surface (about 20 ºN to 20 ºS)
Consistently warm (all months > 18ºC/64.4 ºF)
Annual precipitation exceeds evaporation
Daily temp range exceeds annual temp range
Subcategories based on rainfall (ITCZ influence)
– Tropical rainforest
– Tropical monsoon
– Tropical savanna
Tropical Rainforest (Af)
• High rainfall all year (>2” /
month)
• Straddles Equator by 5o - 10o
Tropical Rainforest
– Vegetation : Highest biomass on earth! Highest
biodiversity on earth! Thousands of species, tall trees, many
canopy layers, evergreen, broadleaf trees, epiphytes, lianas
(vines), climbers, stranglers, ferns
– Fauna: More species than all other biomes combined!, colorful
insects, amphibians, reptiles, and birds, few large animals, high
density of biomass and incredible species diversity
• Other: Among most threatened biomes
Lianas
Epiphytes
Buttresses
Deforestation, Malaysia
Strangler Fig
3-Toed Sloth, Panama
Savanna (Aw) – Tropical Grassland Climates
• Region/Distribution: Subequatorial Africa,
and South America, Southern India (25° N
and S Latitude)
• Vegetation: Continuous cover of grasses,
scattered trees or shrubs
• Fauna: Large grazing animals; antelope,
zebra, giraffe, elephant, Predators: lions,
leopards, cheetahs, hyenas
Masai Reserve, Kenya
• Other: Susceptible to desertification
Acacia and Wildebeest
Serengeti Plain, Tanzania
Dry / Semiarid Climates (B)
• Occupy about 1/3 of Earth’s land area
(Most extensive climate over land surface)
• Evaporation exceeds precipitation
(water deficit)
• Subcategories
– Desert (BW)
– Steppe (BS)
Dry Arid / Semiarid Climates (B)
Deserts (BW): dry
Deserts (BW):
Temperature:
• Widest range: up to 100oF/day!
• Hot at low latitudes, wide
variation at higher latitudes
Precipitation:
• Scarce: <10 inches/year
• Unreliable: wide variation
from average
• Intense: convective downpours
Desert Causation:
• High Pressure Cells and
resultant stability
• Rainshadows
Deserts
• Vegetation: Widely scattered thorny bushes,
cacti, small flowers, extensive shallow roots
or long tap roots, shrubs, succulents
• Fauna: Many rodents, lizards, toads, snakes
and other reptiles, many birds, owls,
vultures, many insects (adaptive strategies)
• Other: Deserts cover roughly 1/3 of earth.
May be growing due to desertification.
• Steppe: semi-arid high elevation or high
latitude
Desert Plant Survival Strategies
 schlerophyllous adaptations
- small, waxy leaves or thorns
replace leaves
 succulents - stems modified
to spongy water storage
structures
 ephemerals (obligate seeders)
- fast reproductive cycle
 wide spacing with shallow
roots - collect sparse rainfall
Animal survival strategies?
Death Valley, CA
Anza-Borrego State Park, CA
Winter 2004/2005
Organ Pipe Cactus
Organ Pipe National Monument, Arizona
Steppe (BS): temperate grasslands
• more precipitation than BW
• narrower temperature ranges
• grasslands
Grassland (temperate)
• Region/Distribution: Central North America, parts
of Africa, Australia, SE South America (Pampas)
• Soil: very fertile soils, best on earth
• Vegetation: Grass tall to short prairie, pampas,
steppe. Sod forming grasses, Sparse bushes,
occasional trees in some areas
• Fauna: large grazing animals, bison, antelope, wild
horses, kangaroos, giraffes, burrowing animals:
rabbits, prairies dogs…; predators: coyotes, lions,
leopards…...
• Other: Most N. American grasslands have been
converted to agricultural fields. Wild grazers replaced
by cattle, sheep, goats. Less than 1% of original grasses
left.
Mesothermal Climates (C)
• “Middle temperature”
• True seasonality
(air mass conflict)
• Subdivisions based on
precipitation variation
– humid subtropical
– marine west coast
– Mediterranean
Marine West Coast
Temperate Rainforest
Olympic Peninsula, Washington
Subtropical Forest
Sarasota, Florida
Mesothermal Climates (C)
Humid Subtropical
Marine West Coast
Mediterranean
• Hot summer, substantial
Humid Subtropical year-round precipitation
• Low latitude east coasts
Midlatitude Forests
(warm currents).
• Summer max precipitation.
• Cold spells
Cfa - New Orleans, LA
Temperate Forest (Deciduous)
• Region/Distribution: Western Europe, East Asia,
Eastern U.S.. Between 30-50° north or south
• Soil: brown soils, good for agriculture
• Vegetation: Broad-leafed deciduous trees, (120150’ tall), oaks, hickories, maples,…
• Fauna: mammals such as white tail deer,
porcupines, raccoons, rabbits, squirrels, most
carnivores eliminated by hunting i.e. wolf,
mountain lion, bobcat; many birds; frogs and
salamanders, snakes
• Other: Biota well adapted to seasonality
including hibernation, migration
Mediterranean
• Dry summers (shifting
subtropical highs)
• Surrounds Mediterranean
• Also on west coasts near 30o N
and S (Australia, S. Africa,
Chile)
Chapparal
Mediterranean
• Region/Distribution: West coast and Central
California, SW. Australia, tip of S. Africa, West
Peru. Chile, Mediterranean (good wine places!)
• Vegetation: Grassland, scattered trees (oaks,
eucalyptus), scrub. Fire tolerant, sclerophyllous
(hard leaf) evergreens, chaparral (scrubby
evergreen)
• Fauna: Burrowers like ground squirrels, gophers;
deer, mountain lions, coyotes, many birds
• Other: Susceptible to fire during dry season, some
species need fire to regenerate, Susceptible to
erosion and desertification, development,
Manzanita
Microthermal Climates (D)
Virtually restricted to Northern Hemisphere.
• 50o-70o N latitude
• long, bitterly cold winters
• highest annual temp range: up to
100O F
•Great annual temperature ranges
(continentality, air mass conflicts)
Dw – Calgary, Canada
Coniferous (Boreal) Forest – Koppen D
• Region/Distribution: Northern parts of
North America, Europe and Asia, South So.
America, much of Russia
• Vegetation: Coniferous (mostly evergreen)
forest, ex. Spruce, Fir, Pine, Larch, needleleaved
• Fauna: Large herbivores: moose, elk; small
herbivores: squirrels snowshoe hare, beaver;
Predators: wolves, foxes, bears, lynx, weasel
family; Mosquitoes in summer
• Other: Acid rain, logging , oil drilling,
hunting of predators
Fir Trees, Alaska
Spruce Needles
British Columbia
Polar Climates (E)
- all months < 50OF
Polar Climates (E)
- all months < 50OF
• Tundra (ET)
– warmest month 32-50F
• Ice caps (EF)
– warmest month below 32F
• Both have very low precipitation
Highland Climates (H)
How are these like the poles? How different?
Highland Climates (H)
How are these like the poles? How different?
• Lower temperatures
• More moisture available
• More insolation
• High winds in both
Where in the world is?…..
Verkhoyansk, Russia (67.4 N, 133.3 E)

Where in the world is?…..
Iquitos, Peru (3.4 S, 73.2 W)

Where in the world is?…..
Hilo, Hawaii

Where in the world is?…..
West Point, NY

Where in the world is?…..
San Francisco, California

The Köppen Climate
Classification
• A Tropical (equatorial regions)
• B Deserts (arid, semiarid)
• C Mesothermal (mild winter)
• D Microthermal (boreal, cold winter)
• E Polar (always cold)
• H Highland (mountains, plateaus)
The Köppen Climate
Classification
• A Tropical (equatorial regions)
• B Deserts (arid, semiarid)
• C Mesothermal (mild winter)
• D Microthermal (boreal, cold winter)
• E Polar (always cold)
• H Highland (mountains, plateaus)
Riparian
Vegetation
Vegetation that grows along
water courses.
Often supports richer
diversity of plant and
animal life, including
more hardwood trees in a
dry environment.
Vertical Zonation of Vegetation
Vegetation Succession
Pioneer Stage
Climax Stage
Occurs after disturbances: fires, storms, landslides, etc.
Ecological Invasions
California Invasive Species: Old World Grape, livestock,
Eucalyptus (Gum Trees), wild hog, mustards, horse,
Mediterranean grasses/mustards
Methods of Transfer
• Domesticated animals (fur,
droppings)
• Ornamentals
• International tourism/migrations
(New Zealand)
Problems with Invasives
• Often out-compete endemics.
• Don’t provide habitat for local
fauna.
• Upset balance of ecosystem.
The American Chestnut
100 feet tall, thick symmetrical branches, over an acre of
greenery, about a million lush leaves in all. Massive
quantities of protein-rich nuts.
In 1904 a handful of Asian chestnut trees were planted in
New York City at the Bronx Zoo. An Asian chestnut blight
quickly destroyed over 99.99 percent of the American
Chestnut population - almost all of four billion trees annihilating at least six specialized insect species,
decimating wild turkey populations, and depriving humans
of a priceless resource in a single generation.
This loss represented one fourth of the tree cover in
the Appalachians!