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