Uneven Solar Heating and Latitude
Earth as a whole is in thermal equilibrium, but different latitudes are not.
Moving masses of air and ocean currents transport energy from
locations with a surplus to those with a deficit.
Cell 3 North
Model of global air
The direction of air
flow and the ascent
and descent of air
Moist air rises — rain
forest and grassland
Cell 2 North
Cell 1 North
Tropical deciduous forest
Tropical deciduous forest
forest and grassland
Cell 1 South
Cell 2 South
Moist air rises — rain
dry air Author-Guru IB/ESS
Cell 3 South
Generalized effects of altitude and latitude on climate and biomes.
Parallel changes in vegetation occur when moving from the
Equator to the poles or from the lowlands to mountaintops.
Ice and snow
DIVERSITY is a generic term for
heterogeneity. If may refer to:
1. Genetic diversity is the total number of genetic
characteristics of a specific species.
2. Habitat diversity is the diversity of habitats in a given
3. Species diversity
a. Species richness – total number of species.
b. Species evenness – relative abundance of each
c. Species dominance – the most abundant species.
Figure A and B have
the same species
What is Biome?
A biome is a specific area characterized
by the animals and plants that live
within it, the climate conditions, the
amount of water available, the soil
conditions, and the location of the area.
What is tropical rainforest ?
A tropical rainforest is an ecosystem usually
found around the equator,
They are common in Asia, Australia, Africa,
South America, Central America, Mexico and
on many of the Pacific Islands.
Rainforests are home to half of all the living
animal and plant species on the planet.
Tropical rain forests are called the "world's
largest pharmacy" because over one-quarter of
modern medicines originate from its plants.
The tropical forests are restricted to the small land
area between the latitudes 22.5 North and 22.5
South of the equator, or in other words between
the Tropic of Capricorn and the Tropic of Cancer.
Since the majority of Earth's land is located north
of the tropics, rainforests are naturally limited to a
relatively small area.
Central America is famous for its large number
of tropical birds, including many kinds of
This region was once entirely covered with
rainforest, but large areas have been cleared for
cattle ranching and for sugar cane plantations.
The photograph below shows a particular ecosystem.
1.State and briefly describe the ecosystem shown in the photograph
2. State whether you would expect ecosystems of the type shown in the
photograph to have a low, medium or high level of abiotic factors.
The Amazon is the world's largest and most famous
The Amazon is home to more species of plants and
animals than any other ecosystem on the planet and
perhaps 30% of the world's species are found there.
American rainforests are most threatened today with
large-scale agriculture (especially soybeans), clearing
for cattle pasture, subsistence agriculture by poor
farmers, and logging.
Central Africa holds the world's second largest
To the south east, the large island of Madagascar was
once intensively forested, but now much of it is gone.
Africa contains areas of high cloud forest, mangrove
swamps and flooded forests.
The island of Madagascar is home to many unique
plants and animals not found anywhere else.
• The rainforests of Asia stretch from India and
Burma in the west to Malaysia and the islands
of Java and Borneo in the east.
• In Southeast Asia the climate is hot and humid
all year round. In the mainland Asia it has a
subtropical climate with torrential monsoon
rains followed by a drier period.
What is Freshwater Biome?
The freshwater biome is a low-saline, or sweet
water, aquatic biome that covers one fifth of the
Streams, rivers, swamps, bogs, ponds, lakes,
ditches, puddles, and canals comprise the
tributaries of the freshwater biome.
Animals and plants in this biome might reside
along the bank, beneath open water, on the
surface of the water, or move between water and
an adjacent biome.
These regions range in size from just a few
square meters to thousands of square
kilometers. Scattered throughout the earth.
Many ponds are seasonal, lasting just a couple
Ponds and lakes may have limited species
diversity since they are often isolated from one
another and from other water sources like
rivers and oceans.
Streams and rivers
These are bodies of flowing water moving in
Streams and rivers can be found everywhere
— they get their starts at headwaters, which
may be springs, snowmelt or even lakes, and
then travel all the way to their mouths, usually
another water channel or the ocean.
Numerous aquatic green plants and algae can
be found in these bodies.
Since there is less light, there is less diversity
of flora, and because of the lower oxygen
levels, fish that require less oxygen, such as
catfish and carp, can be found.
1.Name an organism in an ecosystem that you have studied and state one abiotic
factor that might affect this organism.
Wetlands are areas of standing water that
support aquatic plants.
Marshes, swamps, and bogs are all considered
wetlands. Plant species adapted to the very
moist and humid conditions are called
These include pond lilies, cattails, sedges,
tamarack, and black spruce. Marsh flora also
include such species as cypress and gum.
These support different species of animals,
such as shrimp, shellfish, and various grasses.
What is Marine Biome?
The marine biome includes all the water that is on
the earth's surface.
The marine biome covers three fourths of the earth.
There are thousands of animals and plants in the
Marine regions cover about three-fourths of the
Earth's surface and include oceans, coral reefs, and
Marine Biomes are classified into three types.
• Coral reefs
The largest of all the ecosystems, oceans are
very large bodies of water that dominate the
The ocean regions are separated into separate
zones: intertidal, pelagic, abyssal, and benthic.
All four zones have a great diversity of
The intertidal zone is where the ocean meets the
land — sometimes it is submerged and at other
times exposed, as waves and tides come in and
The pelagic zone includes those waters further
from the land, basically the open ocean.
The pelagic zone is generally cold though it is
hard to give a general temperature range since,
just like ponds and lakes
The benthic zone is the area below the pelagic
zone, but does not include the very deepest
parts of the ocean
The bottom of the zone consists of sand, slit,
and/or dead organisms.
The deep ocean is the abyssal zone. The water
in this region is very cold (around 3 C), highly
pressured, high in oxygen content, but low in
• Tundra is the coldest of all the biomes. Tundra
comes from the Finnish word tunturi, meaning
• It is noted for its frost-molded landscapes,
extremely low temperatures, little precipitation,
poor nutrients, and short growing seasons.
• Dead organic material functions as a nutrient
pool. The two major nutrients are nitrogen and
phosphorus. Nitrogen is created by biological
fixation, and phosphorus is created by
Biomes of the World
1. The Tundra
1. Extremely cold climate
2. Low biotic diversity
3. Simple vegetation structure
4. Permafrost limited drainage
5. Short growing season
6. Energy and nutrients in the form
of dead organic material
7. Large population oscillations
alpine vs arctic tundra
Characteristics of tundra include:
• Extremely cold climate
• Low biotic diversity
• Simple vegetation structure
• Limitation of drainage
• Short season of growth and reproduction
• Energy and nutrients in the form of dead
• Large population oscillations
• Tundra is separated into two types:
• Arctic tundra
• Alpine tundra
• Arctic tundra is located in the northern
hemisphere, encircling the north pole and
extending south to the coniferous forests of the
• The growing season ranges from 50 to 60 days.
• The average winter temperature is -34 C, but
the average summer temperature is 3-12 C
(37-54 F) which enables this biome to sustain
• There are no deep root systems in the
vegetation of the arctic tundra, however, there
are still a wide variety of plants that are able
to resist the cold climate.
• There are about 1,700 kinds of plants in the
arctic and subarctic, and these include:
• Low shrubs, sedges, reindeer mosses,
liverworts, and grasses
• Animals are adapted to handle long, cold
winters and to breed and raise young quickly
in the summer.
• Animals such as mammals and birds also
have additional insulation from fat.
• Many animals hibernate during the winter
because food is not abundant.
• Alpine tundra is located on mountains
throughout the world at high altitude where
trees cannot grow.
• The growing season is approximately 180
• The nighttime temperature is usually below
freezing. Unlike the arctic tundra, the soil in
the alpine is well drained.
• The plants are very similar to those of the arctic
ones and include:
• tussock grasses, dwarf trees, small-leafed shrubs,
• Animals living in the alpine tundra are also well
• Mammals: pikas, marmots, mountain goats, sheep,
• Birds: grouselike birds
• Insects: springtails, beetles, grasshoppers, butterflies
The desert biome
• Deserts cover about one fifth of the Earth's
surface and occur where rainfall is less than
• Most deserts have a considerable amount of
specialized vegetation, as well as specialized
vertebrate and invertebrate animals.
• Desert biomes can be classified according to
There are four major types of deserts:
Hot and dry Desert
Hot and dry desert
• Hot and dry desert present in North American
• The seasons are generally warm throughout the
year and very hot in the summer.
• The winters usually bring little rainfall.
• Desert surfaces receive a little more than twice
the solar radiation received by humid regions .
• The animals include small nocturnal (active at
• The dominant animals are burrowers and
kangaroo rats. There are also insects, arachnids,
reptiles and birds.
The major deserts of this type include the
Sagebrush of Utah,
Montana and Great Basin.
They also include the North America,
Newfoundland, Greenland, Russia, Europe and
• These deserts occur in moderately cool to
warm areas is the coastal desert.
A good example is the Atacama of Chile.
• The soil is fine-textured with a moderate salt
• These deserts are characterized by cold winters
with snowfall and high overall rainfall
throughout the winter and occasionally over the
• They occur in the Antarctic, Greenland and the
Nearctic realm. They have short, moist, and
moderately warm summers with fairly long,
The Atacama desert is, according to NASA, National Geographic and many other
publications, the driest desert in the world
• The heaviest rainfall of the spring is usually in
April or May. In some areas, rainfall can be
heavy in autumn.
• The burrowing habit also applies to carnivores
like the badger, kit fox, and coyote.
The 10 largest deserts
Arabian Desert (Middle
Gobi Desert (Asia)
Kalahari Desert (Africa) 900,000
Great Victoria Desert
Syrian Desert (Middle
Great Basin Desert
Which is the biggest cold desert in