Transcript Earth`s Biomes

Earth’s Biomes
Chapter 23
Section 4
Biome
A
group of ecosystems with similar
climates and organisms.
 Mostly determined by temperature
and precipitation
 There are 6 major land, or
terrestrial, biomes and 2 major
water, or aquatic, biomes.
 Some areas of earth’s surface, such
as mountains and the ice caps, do
not fall into a major biome.
Grassland Biome
 Receives
between 25 and 75 cm of
rain a year.
 Populated
plants.
by grasses and non-woody
 Grasslands
in the middle latitudes
are called prairies.
 Grasslands
located close to the
equator are called savannas.
 Savannas
can receive as much
as 120 cm. of rain a year.
 Grasslands
are home to many large
grazing herbivores.
TUNDRA AND DESERT BIOMES
Desert Biomes
 Receives
less than 25 cm. a year
 Very, very dry because the amount
of evaporation is greater than the
amount of precipitation.
 Very hot during the day but much
cooler at night
 Organisms living here are adapted to
living in dry, hot conditions.
Tundra Biome
 Extremely
cold and dry
 Very little precipitation (no more
than a desert)
 Frozen soil is called permafrost
 Has a short growing season
when many mosses, grasses,
and shrubs grow.
FOREST BIOMES
Deciduous Forest
Biome
 Trees
growing here shed their leaves
and grow new ones
each year.
 Receives at least 50 cm. of rain a yr.
 Temperatures vary throughout the
year.
 Some animals enter a state of
hibernation, a low energy state
similar to sleep.
Boreal Forest Biome
 Contains
coniferous trees,
which produce seeds in cones
and have needle-shaped leaves.
 Very long, cold, snowy winters and
much milder summers
 Also called the taiga.
 Many animals here are herbivores
and eat the seeds produced by the
conifers.
Rainforest Biome
 Two
types: tropical rainforest and
temperate rain forest.
 Receives more rain than any biome
 Very biologically diverse, with a large
number of different plants
and animals living here.
Tropical rainforest:
– Found close to the equator
– Very warm and humid
– Tall trees form a leafy roof
called a canopy.
– A second level of smaller
trees and vines form an
understory
 Temperate Rainforest
– Found farther north
– Also receives a lot of rain
(300 cm. a year)
– Much cooler

Aquatic Biomes
Freshwater Biomes
 Includes
rivers
ponds, lakes, streams, and
 Only
enough sunlight for
photosynthesis near the surface and
in shallow water
 Algae
 Ponds
is the most common producer
and lakes are still water while
rivers and streams are moving water
Marine Biomes
Ocean contains different
zones
 An estuary is where fresh
water of a river meets the
salt water of the ocean.
 The part of the shore
between the highest high tide
and the lowest low tide is
called the intertidal zone.
 The region of shallow water
over the continental shelf is
called the neritic zone

 Surface
zone contains algae that
carry out photosynthesis
 The
deep zone is completely dark so
no photosynthesis can occur.
– Animals in this zone feed on remains of
organisms that sink down from the
surface zone.