Science AHSGE: Standard VI1, part 4 Biomes of the World

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Science AHSGE Standard VI-1, part 4-Biomes of
the World
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What is a biome?
Largest geographic biotic unit, a major community
of plants and animals with similar life forms and
environmental conditions.
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How are biomes formed?

• Distributed across the Earth based primarily on
  climate.
• Similar climate similar biomes

• Latitude affects climate
• The farther north or south of the equator, the
  colder the temperature
• Elevation affects climate
• The higher, the colder.
• Elevation and latitude often similar

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How many terrestrial biomes are there?
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Terrestrial Biomes
Some disagreement among scientists,most agree on
these

• Tropical Rainforest
• Tropical Savanna
• Desert
• Chaparral
• Grassland
• Temperate Deciduous Forest
• Temperate Boreal Forest
• Tundra

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Native Species

• Indigenous- Naturally from an area
• Characteristic of an ecosystem
• Keystone species- Organism that is vital to an
  ecosystem
• Without it, ecosystem would fail
• Examples
• Beavers- create ponds, streams or swamps
• Otters- control sea urchin populations in kelp
  beds
• Grizzly bears- provide nourishment to forest
  floor with salmon carcasses
• Elephants- transform landscape to make more
  accessible
• Prairie dogs and gopher tortoises- Dig burrows
  and tunnels other animals use

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Tropical Rainforest

• Near the equator
• More than 200 cm of rain annually
• Temperatures typically fall between 20oC and 25oC
  (68-77 F) for the entire year
• 50 of all the worlds animal species may be
  found here
• Multiple canopy layers
• Large amounts of transpiration
• Highest biodiversity birds, bats, small mammals,
  insects, monkeys, and jaguars orchids,
  bromeliads, vines, ferns, mosses and palms

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Tropical Savanna

• Grasslands/few scattered trees
• Wet and dry season
• Hot temperatures
• Annual rainfall is between 50 and 127 cm
• More species of grazing mammals than any other
  biome
• Animals migrate
• Lions, zebras, giraffes, hyenas, etc.

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Desert

• Between 25o and 40o latitude
• Less than 25 cm of rain annually
• Temperatures range between 20oC and 25oC
  (68-77F) but some extreme deserts can reach
  temperatures higher than 38oC (100F) and lower
  than 15oC (5F)
• Animals burrow and remove water from food
  Kangaroo rats (rodents), rabbits, skunks, and
  burrowing owls, reptiles, and birds all mostly
  active at night
• Succulents and plants with very reduced leaf
  surfaces

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Chaparral

• Between 32o and 40o latitude on the west coast of
  continents
• Between 35 and 70 cm of rain, usually in the
  winter
• Extremely resistant to drought and weather events

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Temperate Grassland

• Dry climate/trees are found only near water
  sources such as streams
• Between 50 and 90 cm of rainfall each year
• Summer temperatures can reach up to 38oC (100F),
  and winter temperatures can fall to 40oC (-40F)
• Prairie dogs ground owls
• Broad-leaf trees and many wildflowers
• Nutrient-rich soil with thick topsoil layer

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Temperate Deciduous Forest

• Moderate climate
• Most trees will lose their leaves in the winter
• Temperatures range between 30oC and 30oC (-22 F
  to 104 F)
• 75 to 150 cm of precipitation
• Well developed understory
• High biodiversity deer, squirrels, mice,
  raccoons, salamanders, snakes, frogs, and insects

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Temperate Boreal Forest

• Also known as Taiga (coniferous forest)
• Between 45o and 60o North latitude
• Cold climate with summer rains
• Patchy permafrost- permanently frozen soil
  starting as high as a few centimeters below the
  surface which severely limits plant growth
• Many lakes, ponds, rivers and bogs
• Very few reptiles
• Limited understory
• Snow is primary form of precipitation (40 100
  cm annually)
• Mosses and evergreen trees drought resistant
• Summer birds and insects, bears, moose, etc.

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Temperate Boreal Forest
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Tundra

• Means treeless or marshy plain
• Prairie potholes
• Characterized by permafrost Winter temperatures
  average 34oC (93F) while summer temperatures
  usually average below 10oC (50F)
• Lowest precipitation (1525 cm per year) but
  ground is usually wet/snow because of low
  evaporation
• Coastal species polar bears, seals, penguins
• Inland Caribou, ducks and geese
• Low-growing plants with shallow roots reproduce
  by budding

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Tundra
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Antarctic Desert

• Low precipitation
• No permafrost
• Low species diversity
• Moss and algae vegetation
• Lichens
• Some invertebrates

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Aquatic Biomes- Water

• Most stable average daily temperature
• Freshwater- Low to no salinity
• Glacial lakes
• Rivers
• Lakes/ponds
• Estuary- brackish
• Varying salinity levels
• Marine- ocean
• High salinity level

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Estuarian Biome
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Marine Biome