Name ______________________________________________
Date ______________________
Biogeography and Earth’s Biomes
(p 56-73)
Questions to think about:
How does dispersal of organisms occur?
What factors can limit the distribution of a species?
Biogeography is the study of where organisms live Bio = live, geo= earth, graph = description
Continental Drift (p 56-57)
= slow motion of the continents
Continents are huge blocks of solid rock floating on a layer of hot, dense liquid
225 myo Pangea existed
Species were spread out
Means of Dispersal (p 57-58)
3 ways= wind, water or living things (including humans)
Wind/Water = things move via wind—ie spores, tiny spiders other light things, floating
Other living things= ie goldfinch eats seeds and deposits them elsewhere, a duck carries algae on its feet
Native species = natural evolved in an area
Exotic species = organism carried into an area- can cause problems
Limits to Dispersal (p 58-59)
3 Factors:
Physical barriers- ie water, mountains, deserts
Competition – ie if an organism enters a new area, it must find a new niche—it will have to outcompete
Climate – determined by temperature and precipitation—conditions are different at the top of the mountain
than at the bottom of the mountain—only certain things can live in both areas
Next up… EARTH’S BIOMES….. (pp 62-73)
Questions to think about:
What determines the type of biome found in an area?
Where can photosynthesis occur in biomes?
Two things that mostly determine climate conditions ___temperature____ and ___precipitation____
BIOME
Tropical rain forest
RAINFALL
High levels
125-660 cm/yr
TEMPERATURE
BIOTIC
FACTORS
ADD’L INFO
Very warm 93 F
Orangutan
Oahu tree snails
Contain several
layers of trees and
plants- canopy
Temperate rain forest +300 cm
Rarely freeze or get
over 80 F
Cedars
Redwoods
Along northwest
coast of US
Desert
<25 cm
Great range
Cactus
Gila monster
Organisms need to
be adapted to a range
of temps and rain
Grasslands
(and savannas)
25-75 cm
…120 cm
Below freezing-70 F
Bison
Antelope
zebras
Some of the largest
land animals in the
world live here
Deciduous forest
50 cm
Varying temps—
average yearly 50 F
(seasons)
White-tailed deer
Black bear
This is our biome
Boreal forest
70 cm (a lot of snow) Varying temps
-65- 70 F (seasons)
Coniferous trees
Moose
Lynx
Seeds are a major
food source
Tundra
15-25 cm
Average annual -18
F
Mosses
Caribou
Caribou scrape away
snow to find lichen
on trees
Mountains and ice
Varies—in the form
of snow
Usually never above
freezing 32 F
Penguins
Polar bears
seals
Covered year round
with thick sheets of
ice
Ponds and Lakes
Warmer—near the
surface
Algae, frogs, sunfish
Standing or still
water
Streams and Rivers
Depends on location
Trout
Insects
Organisms must be
adapted to strong
current
Estuaries (salt meets
fresh)
Depends on location
Marsh grasses
Tricolored heron
Calm waters can be
used for breeding
grounds
Intertidal zone
Depends on location
Sea stars
Crabs
clams
Must be able to
withstand pounding
water
Neritic zone
Cooler…
Sardines
Anchovies
Still able to use sun
for photosynthesis
Surface Zone
Even cooler…
Light can enter up to
a few hundred
meters
Deep zone
Coldest! Near
freezing
Algae
Tuna
Swordfish
whales
Giant squid
Angler fish
Completely dark!