W1 Earth's Biomes

Question 1

Tundra:

Answer 1

-Arctic and alpine regions
-Cold winters (< -30C) and cool summers (<10C)
-Permafrost restricts growth of plant roots
-Vegetation includes mosses, grasses, forbs, dwarf, shrubs, trees, lichen
-Animals include musk ox, reindeer, bears, wolves, foxes, migrating birds in summer
-Threats include oil and mineral extraction

Question 2

Taiga:

Answer 2

-Northern coniferous forest - North american and Eurasia
-Largest terrestrial biome
-Precipitation varies: periodic droughts, wetter in coastal areas
-Cold winters, summers can be hot
-Animals include migratory and resident birds, moose, brown bears, siberian tigers
-Threats include logging

Question 3

Temperate forests:

Answer 3

-Mid latitude in Northern Hemisphere, plus Chile, South Africa, Australia and NZ
-Significant precipitation
-Winters average 0C, summers hot and humid
-Dominant plants are deciduous trees, with evergreen eucalyptus in Australia
-Few mammals - hibernation important for winter. Species; squirrels, martens, bears, badgers, deer
-Threatened by human settlement and logging

Question 4

Grassland:

Answer 4

-Many continents
-Highly seasonal precipitation
-Cold and dry winters, hot and wet summers
-Grasses and forbs dominate and are adapted to drought and fire
-Native mammals include bison, wild horses and prairie dogs
-Threats include land use change

Question 5

Desert:

Answer 5

-Occur in bands near 30 degree north and south of the equator
-Low, highly variable precipitation. Typically <30cm/y
-Seasonal and daily temperatures high variable
-Can be hot or cold
-Plants such as cacti are heat and desiccation tolerant
-Many desert animals are nocturnal, with adaptations for water conservation
-Threats include urbanization and irrigated agriculture

Question 6

Tropical rainforest:

Answer 6

-Equatorial and subequatorial regions
-Relatively constant rainfall
-High temperatures year round with little seasonal variation
-Forests are vertically layered, with intense competition for light
-Animal diversity higher than any other biome
-Threats include deforestration and land-use change

Question 7

Savanna:

Answer 7

-Equatorial and subequatorial regions
-Seasonal precipitation, with dry seasons of 8-9m
-Average temperatures 24-29C
-Dominant plants are fire adapted
-Grasses and forbs dominate ground cover
-Large herbivores common, but insects are the dominant herbivores
-Threats include overhunting and land-use change

Question 8

Chaparral:

Answer 8

-Mid latitude coastal regions, several continents
-Cool, rainy winters and hot, dry summers
-Dominated by shrubs, small trees, grasses and herbs. Many plants fire and drought adapted
-Animals include amphibians, birds, reptiles, insects, browing mammals
-Threats include human settlement and fires

Question 9

Zonation in oceans:

Answer 9

-Zones are defined by light penetration, temperature and depth
-Intertidal zone: Periodically submerged and exposed by tides
-Pelagic (offshore) zone: The upper photic zone which has sufficient light for photosynthesis + the lower aphotic zone, which receives little light
-Benthic zone: Organic and inorganic sediment at the bottom of all aquatic zones
-Abyssal zone: Located in the aphotic zone with a depth of 2000 to 6000m.

Question 10

Zonation in lakes:

Answer 10

-Rooted and floating aquatic plants live in the shallow, well-lit littoral zone close to shore
-Phytoplankton inhabit the limnetic zone, where the water is too deep to support rooted plants
-Zooplankton are drifting heterotrophs that graze on the phytoplankton
-Invertrebrates live in the benthic zone
-Fishes live in all zones with sufficient oxygen