Blue Marble Photograph p. 6
Chapter 1: Biomes & ecosystems are
divisions of the biosphere
1.1 Biomes
By 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.
• P. 13
Distribution of Biomes
Other identifying factors include:
• 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.
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