Chapter 1: Biomes & ecosystems are divisions of the biosphere 1.1 Biomes • Biomes are regions with similar biotic & abiotic 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 8biomes 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.
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 right hand y-axis, temperature on the left hand y-axis and time along the x-axis (bottom)
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: • Structural adaptation - a physical feature • that helps an organism survive. • ex. A wolf has large paws to help it • run in snow. • 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