global climate classification and vegetation relationships
TRANSCRIPT
Global Climate Global Climate Classification Classification
andand Vegetation Vegetation
RelationshipsRelationships
Weather vs. ClimateWeather 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 DeterminantsClimate 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 systemFirst 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
Buttresses
Lianas
Epiphytes
Strangler Fig3-Toed Sloth, Panama
Deforestation, Malaysia
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
• Other: Susceptible to desertification
Acacia and Wildebeest Serengeti Plain, Tanzania
Masai Reserve, Kenya
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):
Desert Causation: • High Pressure Cells and resultant stability• Rainshadows
Precipitation: • Scarce: <10 inches/year• Unreliable: wide variation from average• Intense: convective downpours
Temperature: • Widest range: up to 100oF/day!• Hot at low latitudes, wide variation at higher latitudes
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 CactusOrgan 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
Subtropical Forest Sarasota, Florida
Marine West CoastTemperate Rainforest
Olympic Peninsula, Washington
Mesothermal Climates (C)
Humid SubtropicalMarine West Coast
Mediterranean
Humid SubtropicalMidlatitude Forests
• Hot summer, substantial year-round precipitation
• Low latitude east coasts (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, (120-150’ 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, threatened biome
Manzanita
Microthermal Climates (D)
Virtually restricted to Northern Hemisphere.
Subarctic Climates (Boreal or Taiga)• 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, needle-leaved
• 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
British Columbia
Spruce Needles
Polar Climates (E)- all months < 50OF
Polar Climates (E)- all months < 50OF
• Tundra (ET)– warmest month 32-50F
• Ice caps (EF)– warmest month below 32F
• Both have very low precipitation
Tundra
Region/Distribution: North of the Boreal Forest, high latitudes of northern hemisphere in a belt around the Arctic Ocean, near the coast Soil: Permafrost, no true soil development Vegetation: Low growing lichens, mosses, grasses, sedges, dwarf shrubs, small plants typically ground hugging or warmth preserving in some wayFauna: Small burrowing mammals, lemmings, also foxes, lynx, owls, grizzly bear, caribou and musk ox: migrants Other: many insects in summer, standing water
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 InvasionsCalifornia 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 Chestnut100 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!