Geography 316:  Biogeography
(Lecture:  9/23/02  )

BIOMES
Please check out Professor Susan Woodward's Biome Web page for more detail on each biome.
Biomes
 Definition
 Structural Components
  (life form, size & stratification, coverage, periodicity, leaf shape & size, leaf texture)
 General Biomes
 Specific Terrestrial Biomes
      Tropical Rain forest
      Temperate Deciduous Forest
      Temperate Rain Forest
       Northern Boreal Forest
      Tropical Grassland & Savanna
      Temperate Grassland
       Mediterranean
      Desert
      Tundra
 Aquatic Biomes
      Marine
      Freshwater

 BIOMES

Biome: broad major grouping of natural ecosystems that include animals as well as plant life.

Structural Components
 of Vegetation in Biomes

Life form:  tree, shrub, liana,
    herb, forbs, grass

Size & Stratification

Coverage: how much covered?
  barren......continuous cover

Periodicity:  deciduous vs. evergreen

Leaf Shape and Size: broadleaf, needle leaf

Leaf Texture: succulent, sclerophyllous,    membranous

General Biomes:

Forests
(Tropical, Temperate, Boreal)
Tropical Grasslands and Savannas
Temperate Grasslands
Mediterranean (Chaparral)
Desert
Tundra
Aquatic (Marine, Freshwater)

CONSIDER when looking at biomes consider the following
Characteristics of a Biome
 (Structural Components)
Distribution of a Biome
Climate Characteristics
 (temp & precipitation)
Causes of Biome
  (circulation, topography etc.)
Human Effects

BIOMES of the World

Tundra

Region/Distribution: North of the Boreal Forest, high latitudes of northern hemisphere in a belt around the Arctic Ocean

Climate: Bitter cold, limited sunlight
Temperatures: -57° --15° C (-70° -59° F);
Precip: < 12.7cm (5" per year);
Koeppen ET, short growing season

Soil: Permafrost, no true soil development

Vegetation: Low growing lichens, mosses, grasses, sedges, dwarf shrubs,smal plants typically ground hugging or warmth preserving in some way, rosettes

Fauna: Small burrowing mammals, lemmings, also foxes, lynx, owls, grizzly bear, caribou and musk ox: migrants

Other: many insects in summer

Coniferous (Boreal) Forest 

Region/Distribution: Northern parts of North America, Europe and Asia South So. America, New Zealand, So. Australia

Climate: Extremely long and cold winters, snow
Temperatures: -54° -21° C (-62° -70° F);
Precip: 35-600cm (14-234² );
Koeppen Dfc, Dfd and Dwd

Soil: Podzolization occurs due to acidic soils/ spodosols

Vegetation: Coniferous ( mostly evergreen) forest, ex. Spruce, Fir, Pine, Larch, needle-leaved, short growing season

Fauna: Large herbivores: moose, elk; small herbivores: squirrels snowshoe hare, beaver; Predators: wolves, foxes, bears, lynx, weasel family; Birds: warblers, finches, sparrows, ravens

Other: Acid rain, logging , oil drilling, hunting of predators

Temperate Forest (Deciduous)

Region/Distribution: Western Europe, East Asia, Eastern U.S.. Between 30-50° north or south

Climate: Seasonal
Temperatures: < freezing; -30° - 38° C (-22° -100° F)
Annual rainfall: 60-225 cm (30-80²)
Koeppen: mostly Cfa and Cfb (Dfa)

Soil: Alfisols (brown soils)

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 (neotropical migrants);frogs and salamanders, snakes

Other: Biota well adapted to seasonally including hibernation, migration

Human use: paper/pulp, furniture/industry and acid rain

Temperate Rainforest 
(Marine West Coast)

little seasonality
temperatures colder than tropics
+ 150 cm /year precipitation

Southern Hemisphere
Podocarpus (yellow wood)
Nothofagus (beech)

Northern Hemisphere
Pinus (Pine)
Abies (Fir)

Taxus brevifolia ( Pacific Yew)

 Mediterranean 

Region/Distribution: West coast and Central California, SW. Australia, tip of S. Africa, West Peru. Chile, Mediterranean

Climate: Warm summer/cool winter,
precipitation in winter: 20-65cm (8-25² ), dry in summer
Koeppen: Csa/Csb

Soil: Mollisols, Alfisols

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

Desert

Region/Distribution: Parts of Africa (Sahara and Sahel) Parts of Middle East and Asia, Great Basin of N. America and Southwest U.S., Northern Mexico

Four conditions: High pressure/ West coast/ Rainshadow/Interior

Climate: Very dry
temperatures: 2° -57° C (35° -130° F), high diurnal fluctuation;
Rainfall 0-25 cm (10 ² )/ irregular (flash floods)
Koeppen: BWh and BWk

Soil: Entisols/Aridisols

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 1/3 of the earth’s surface and are growing due to desertification
Links to TRF
Warm and cold deserts:Cold w/ 5-20cm ppt. -40° -42° C

Steppe: semi-arid high elevation or high latitude
 
 

 Grassland (temperate)

Region/Distribution: Central North America, parts of Africa, Australia, SE South America

Climate: Seasonal, Moderate to hot summers, cold winters. Rainfall: 25-75 cm (11-30² ) annually, evenly distributed or high in summer;
Koeppen: BSk, Cf

Soil: Mollisols, very fertile soils

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.
 

Savanna

Region/Distribution: Subequatorial Africa, and South America, Southern India (25° N and S Latitude)

Climate: Hot and dry most of the year, abundant rain in wet season,
High average temperature: 13° -40° C (55° -104° F);
Rainfall 90- 150 cm/yr (30-60² ), during warm wet season
Koeppen: Aw

Soil: Ultisols and Oxisols

Vegetation: Continuos cover of perennial grasses, scattered trees or shrubs

Fauna: Large grazing animals; antelope, zebra, giraffe, elephant, Predators: lions, leopards, cheetahs, hyenas

Other: Susceptible to desertification

Tropical Rainforest

Region/Distribution: Northern South America, Central America, West and Central Equatorial Africa, SE Asia, NW Coastal Australia, Pacific Islands

Climate: Non seasonal, Annual temperature greater than 50° F, mean 82° F(18-35° C).
Almost daily rainfall, heavy annual > 240cm (94.5² )
Koeppen: Af

Soil: Ultisols/Oxisols: Soil fairly thin and poor, most nutrients in vegetative litter.

Vegetation : Thousands of species, tall trees, many canopy layers, evergreen, broadleaf trees, vines, epiphytes, lianas, climbers, stranglers, heterotrophs

Fauna: More species than all other biomes combined, colorful insects, amphibians, reptiles, and birds

 Other: Most exploited and endangered

I

If  you are actually still reading this, the little guy on top is a pygmy possum.
He's a marsupial from PNG. 

Aquatic Biomes 

Marine Biome
oceans cover 70% of earth's surface

Freshwater Biome
lakes, ponds, rivers, streams cover only a small fraction
 

Variants/Factors in Aquatic Biomes
Salinity, pressure, light and tidal cycles, substrate

Salinity
Oceans:  35 parts per thousand
Freshwater: < 0.5 parts per thousand
 Marine Communities

Ocean: essentially continuous and fairly stable

Two most important features:
     light and substrate

Vertical Zonation based on light

Photic Zone: sunlight , penetration increases from coastal waters (~30 meters) b/c of organisms and suspended particles to open ocean (~100+ meters)

** Zone where photosynthesis occurs **

Aphotic Zone: below photic zone, organisms obtain energy by consuming organic material produced in the photic zone

Classification based on bathymetry

Intertidal (Littoral) Zone:  where sea meets land, really an ecotone between land and ocean

Neritic (Sublittoral) Zone:  beyond intertidal zone, few meters to ~200m deep

Bathyal Zone: edges of continental shelf

Abyssal Zone: most of the ocean..deep waters (2000-6000m in depth)

Organisms are also classified:

Benthic or Pelagic (oceanic): Association with substrate or water column

Benthic:
 hard substrates: kelp forests, coral reefs
vs.
 soft muddy substrate: burrowing organisms beneath surface

Pelagic (Oceanic):
Plankton: microscopic organisms that float in water column - simple plants; phytoplankton
 tiny animals: zooplankton

Nekton: comprises the actively swimming animals, i.e. fish, whales, large invertebrates (higher trophic levels)

 Freshwater Biomes

Lotic:  running water
 &
  Lentic:  standing water

Lotic:  running water
Rapids zone
Pool zones

Lentic:
Littoral zone: shallow water where light penetrates to the bottom (vegetation)

Offshore Zone:
 Limnetic zone: where light penetrates (phytoplankton)
 Profundal: beyond depth of effective light penetration

Lakes
Eutrophic:  lakes are shallow-highly productive b/c light penetrates almost to the bottom, good vertical circulation

Oligotrophic: lakes usually so deep that little to no vertical circulation occurs, limited nutrients and limited sunlight restricts primary productivity
 

Other aquatic communities
Hypersaline lakes
Caves
Hot Springs
Estuaries, salt marshes, swamps