Blue Marble Photograph p. 6

Chapter 1: Biomes & ecosystems are divisions of the biosphere

1.1 BiomesBy the end of section 1.1 you should be able to understand the following:A biome is the largest division of the

biosphere.Large regions within biomes have similar

biotic and abiotic components. The interaction of these components determine the characteristics of the biome.

Temperature and precipitation are the most influential abiotic factors on biomes.

Organisms have adaptations for survival in the specific environmental conditions of their biome.

Chapter 1: Biomes & ecosystems are divisions of the biosphere

1.1 Biomes• Biomes are regions with similar biotic (living)

& abiotic (non-living) components (ex. BC & New Zealand are similar biomes)

Classification of Biomes

• Biomes are classified based on many characteristics: water availability, temperature & interactions between biotic & abiotic factors.

• There are 8 biomes on Earth: Boreal forest, desert, grassland, permanent ice, temperate deciduous forest, temperate rainforest, tropical rainforest and tundra.

Distribution of Biomes• Temperature & precipitation are 2 of the

most important abiotic factors in identifying biomes.

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Distribution of Biomes

• Latitude influences both temp. & precipitation.Ex. The tropical zone has very warm temp.

& high Precip. Because the sun shines straight

down & warm air holds more moisture than cooler air.

• Elevation is the height above sea level– Higher elevations have less air, &

therefore less heat is retained.– Windward sides of mountains are wet,

leeward sides are very dry.• Ocean currents carry warmth & moisture to

coastal areas.– Where warm currents meet land,

temperate biomes are found.

Other identifying factors include:

Climatographs

• Climate: the average pattern of weather conditions over a period of several years.– A climatograph shows the average

temperature & precipitation for a location over a period of 30+ years.

– Climatographs show • the precipitation on the left hand y-axis,

• temperature on the right hand y-axis • time along the x-axis (bottom)

Climatographs

Adaptations & Biomes• Biomes are often

identified with biotic factors.– Eg. a cactus in

the desert, or a caribou on the tundra.

• Many of these characteristic factors have special adaptations that allow the organisms to better survive & reproduce in that biome.

• Types of adaptations: 1. Structural adaptation - a physical feature

that helps an organism survive.ex. A wolf has large paws to help it run in snow.

2. Physiological adaptation - a physical or chemical event inside the body of an organism that allows it to survive. ex. A wolf maintains a constant body

temperature.

3. Behavioural adaptation - a behaviour that helps an organism to survive.ex. Wolves hunt in packs to capture large prey.

Take the Section 1.1 Quiz