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Biomes
Biomes
• Community characterized by dominant vegetation and prevailing climate– Climate=avg. temp. and avg. precipitation– General trend: as altitude and latitude
increases, temp. and precipitation decreases
Climatogram
Arctic Tundra
• No match in southern hemisphere
• Extreme northern latitudes (alpine tundra-high elevations; above tree line on mountains)
Arctic Tundra Characteristics
• Long, harsh winters/short summers• Little to no precipitation (driest place on earth)• Nutrient poor soil, little organic matter• Permafrost-permanently frozen ground
– Poor drainage, soil gets waterlogged– Creates bogs in summer– Roots cannot penetrate the ground (no tree species)
• Little diversity, little primary productivity• Regenerates VERY slowly after disturbance
Tundra Plants
• Mosses
• lichen
Tundra Animals
• Lemmings• Weasels• Voles• Arctic fox-(video nat. geo)• Arctic hare• Snowy owl• Musk oxen• Migrators-caribou/birds
Tundra Animals
Tundra Adaptations
• Plants-wax coated leaves, underground as bulbs to over-winter, dehydrate to prevent frost damage
• Animals-thick coats and fur, feathers, small bodies and extremities to prevent heat loss
Threats to the Tundra
• Climate change
• Oil production
• Video-teacher’s domain
Taiga (TIH-ga) Coniferous Forest
• Just south of tundra
• Stretches across N. America and Eurasia
Taiga Characteristics
• Winters are severe and cold
• Short growing season
• Not much precipitation
• Soil is acidic, nutrient poor (partially decomposed pine needles)
• Patchy permafrost
• Ponds, lakes carved by glaciers
Taiga Plants
• Coniferous evergreens (pine trees)
• Spruces, balsam fir
• **extensive logging here**
Taiga Animals
• Caribou
• Wolves
• Bears
• Moose
• Lynx
• insects
Taiga Animals
Taiga Adaptations
• Needles are adapted to prevent water/heat loss (less surface area)
• Keeping needles all year takes full advantage of available sunlight
Temperate Rain Forest
• NW coast of N. America (Seattle), southern S. America
Temperate Rain Forest Characteristics
• High precipitation, condensation from coastal fog
• Coniferous forest (pine trees)
• Temp. modified by ocean (mild winters/cool summers)
• Nutrient poor soil
• High organic content, but decomposition is slowed by cool weather
Temperate Rain Forest Characteristics
• Special, complex ecosystem; old-growth forest, never been logged and only a small fraction remains
• VERY stable
• Includes many endangered or threatened species that only live here
Temperate Rain Forest Plants
• Large evergreens
• Douglas fir
• Hemlocks
• Red cedar
Temperate Rain Forest Animals
• Eagles
• Elk
• Mule deer
• Amphibians/reptiles
• Wood rats
• Spotted owl
Temperate Deciduous Forest
• This is where we live!
• Hot summers/cold winters
• Precipitation 30-50 inch/yr
• Topsoil is rich in organic matter, lower layers mostly clay
Temperate Deciduous Forest Plants
• Oak
• Hickory
• Maple
• Birch
• **lose leaves annually** (Deciduous)
Temperate Deciduous Forest Animals
• White-tailed deer
• Bears
• Birds
• Coyotes
• Raccoons
• skunk
Temperate Deciduous Forest Animals
Temperate Deciduous Forest
• Worldwide these forests have been cleared for farming, logging, cities
• Where they have regenerated many organisms have returned
Temperate Deciduous Forest Adaptations
• Plants that lose leaves are dormant over the cold winter to survive drought and cold weather
Threats to the World’s Forests
• Clearing for agriculture, grazing
• Clearing for timber, urban development
• Conversion to less biodiverse tree plantations
Temperate Grasslands
• Midwest U.S.
• Characteristics: – Hot summers/cold winters– Precipitation uncertain (10-30 in/yr)– Rich organic soil (that’s why there are a lot of
farms
Temperate Grassland Plants
• Dominant vegetation-grasses
• Only a few trees close to rivers/streams
• Wildfires frequent
Temperate Grassland Animals
• Prairie dogs• Snakes• Rodents• Foxes• Black-footed ferrets• Hawks• Insects• Bison• Grouse (birds)
Temperate Grassland Animals
Threats to Grasslands
• Conversion to cropland
• overgrazing
Chaparral
• Coast of California
• Characteristics: thin soil, unfertile
• Long, hot dry summers/mild, wet winters
• **Frequent fires to regenerate plants
Chaparral Plants
• Evergreen shrubs (short, drought resistant)
• Adaptations: hard, leathery leaves to prevent water loss
• Plants grow best after fire
Chaparral Animals
• Wood rats
• Mule deer
• lizards
Chaparral
• Fires burn expensive homes, but letting vegetation build up causes severe fires and clearing vegetation causes mud slides in winter
Deserts
• Both cold (temperate) and hot (tropical)• Characteristics:
– Low water vapor content results in extreme hot and cold temps
– Very low precipitation less than 10 in/yr– Sparse vegetation so soil is low in organic
matter; very high mineral content (amounts so high it can be toxic)
– Perennials: live longer than one year and annuals live one year, happens after rain
Desert Plants
• Xerophytes: cacti, saguaro, aloe vera
• Adaptations: reduced water loss because little or no leaves (photosynthesis happens in the stem), very deep roots or shallow roots that are very wide ranging, equipped with thorns, spines, or toxins to resist grazing pressure
Desert Plants
Desert Animals
• Jack rabbit
• Fennec fox
• Lizards
• Snakes
• rodents
Desert Animals
Desert Animal Adaptations
• Large extremities for heat loss
• Small bodies
• Take cover during the day and forage at night
• Obtain water from plants (dew)
• Concentrated urine, dry feces
Desert Disturbances
• Large desert cities
• Off road vehicles
• Storage of toxic chemicals
• **very slow to recover**
Savanna (Tropical Grassland)
• Tropical grassland• Characteristics:
– Low rainfall or seasonal rainfall with long periods of drought
– Little temp. change year-round– Low in essential nutrients due to leaching– Rich in aluminum because aluminum is leach
resistant (can become toxic)– Dominant vegetation is grasses with scattered trees
Savanna Plants
• Acacia tree
• Adaptations: – Thorns to reduce grazing– Extensive underground roots to survive
drought or fire
Savanna Plants
Savanna Animals
• Lions
• Cheetahs
• Giraffes (ungulates-hooved animals), antelope
• Elephants
• Adaptations: migrate to find water
Savanna Animals
Tropical Rain Forest
• Central/South America, SE Asia
• Characteristics:– Warm temp. year round– Daily precipitation (80-180 in/yr), mostly
recycled water from transpiration– Ancient, highly weathered, mineral poor soil– Little organic matter in the soil because
decomposition happens quickly and reuptake happens quickly
Tropical Rain Forest
• Characteristics continued– Minerals and nutrients are tied up in living
organisms rather than the soil– Highly productive (a lot of photosynthesis)– Greatest biodiversity of all biomes
Tropical Rain Forest Plants
• Broadleaf evergreens (large leaves, all year)
• Epiphytes (plants that grow on other plants-mosses, lianas (woody vines)
• Adaptations:– Leaves are broad to capture sunlight, radiate
heat– Root mats catch and absorb all nutrients
released by decomposers
Tropical Rain Forest Plants
Tropical Rain Forest Animals
• Insects• Amphibians• Sloths• Monkeys• Macaws• Ocelots• Adaptations:
– Many different niches so decreased competition• Some animals never walk the ground• Adapted to certain parts of the canopy
Tropical Rain Forest Animals
Tropical Rain Forest Stratification
Threats to the Rainforest
• As human population grows, expansion into rainforests-demand for land/resources may be the end of the rainforest in this century
• Some species not identified yet – Could be medicines or cures for diseases