Manchester International School
ESS Worksheet
Topic: 2.4 BIOMES
You are encouraged to study at least four contrasting pairs of biomes of
interest to you, such as temperate forests and tropical seasonal forests; or
tundras and deserts; or tropical coral reefs and hydrothermal vents; or
temperate bogs and tropical mangrove forests.
Write an assignment on your selected constrasting pair of biomes.
Contrasting Pair A: Temperate Forests and Tropical Seasonal Forests
Temperate Forests
Climate:
This biome has four changing seasons including winter, spring, summer, and fall. Hence it is
a biome of seasonal weather that witnesses both hot summers and cold winters. The
average temperature in temperate forests is 50°F (10°C). Summers are more often mild, and
average about 70°F (21°C), while winter temperatures are often well below freezing.
Distribution:
Temperate forests are located in the mid-latitude areas which means that they are found
between the polar regions and the tropics.
Structure:
Temperate forests hold a structure of vegetation type with a more or less continuous canopy
of broad-leaved trees. Toward the polar regions they grade into boreal forests, which are
dominated by evergreen conifers, so that mixed forests containing both deciduous and
coniferous trees occupy intermediate areas.
Relative Productivity:
Net primary productivity ranges from 600–1500 g m-2 yr-1 with high litter production. Litter
serves as a major pathway for nutrient recycling in this biome.
Plant and Animal Adaptations:
Trees and plants in the deciduous forest have special adaptations. As the seasons change,
so do the leaves on the trees. The trees lose their leaves in late fall and winter. In spring and
summer, the leaves grow back and are used for photosynthesis.
Animals in deciduous forests have to adapt to changing seasons. They must be able to cope
with cold winters and hot summers. Some animals hibernate or migrate during the winter to
escape the cold. Others grow thick fur and/or layers of fat to help make it through the winter
months. Without the protection of leaves, animals have a more difficult time hiding from
predators in the winter. To help in hiding, some animals such as rabbits and weasels, have
fur that changes colour twice a year. For most of the year, their fur is brown for blending in
with the forest trees, but in winter, their coats turn white to blend in with the snow. The black
bear is one animal that is well adapted to the deciduous forest. The bear has a heavy coat
made up of many layers of fur to keep itself warm in the winter. It also has strong jaws and
long claws for climbing trees and for attacking prey.
Named Examples:
Northeast China Plain, the Great Smoky Mountains National Park (US) and the
European Temperate Deciduous Forest.
Tropical Seasonal Forests:
Climate:
Tropical rainforests are lush and warm all year long. Temperatures don't even change much
between night and day. The average temperature in tropical rainforests ranges from 70 to
85°F (21 to 30°C). The environment is pretty wet in tropical rainforests, maintaining a high
humidity of 77% to 88% year-round.
Distribution:
The major areas of tropical rainforests are in South East Asia, West Africa and South and
Central America. The best-known rain forests are found in tropical regions between
the Tropics of cancer and Capricorn. Temperate rainforests are found along coasts in
the temperate zone.
Structure:
Most tropical rainforests are structured in four layers: emergent, canopy, understory, and
forest floor. Each layer has unique characteristics based on differing levels of water, sunlight,
and air circulation.
Relative Productivity:
In tropical rainforests, biomass is concentrated in woody tissue of trees as most of the
biomass in the rainforest is in the producers. Hence, this biome has extremely
high productivity due to year-round photosynthesis, stable temperature and precipitation.
Plant and Animal Adaptations:
The following adaptations allow plants to survive in the conditions of the rainforest.

Lianas - these are woody vines that have roots in the ground but climb up the trees to
reach the sunlight. Their leaves and flowers grow in the canopy

Tree trunks - these are tall and thin to allow trees to reach the sunlight. The bark on
these trees is smooth to allow water to flow down to the roots easily
Many animals have adapted to the unique conditions of the tropical rainforests. Examples:

The sloth uses camouflage and moves very slowly to make it difficult for predators to
spot

The spider monkey has long, strong limbs to help it to climb through the rainforest
trees

The flying frog has fully webbed hands and feet, and a flap of loose skin that
stretches between its limbs, which allows it to glide from plant to plant
Named Examples:
Amazon Rainforest, Congo Basin, Daintree Rainforest
Contrasting Pair B: Tundras And Deserts
Tundras:
Climate:
The average temperature in the tundra is around -18 degrees F. It gets much colder in the
winter and warmer during its short summer. It's dry - The tundra gets about as much
precipitation as the average desert, around 10 inches per year. Most of this is snow.
Distribution:
This biome is restricted to the high latitudes of the northern hemisphere in a belt around the
Arctic Ocean. Tundra regions are found in the northern and southern hemispheres between
the ice-covered poles and the taiga or coniferous forests. In the north, this biome stretches
across northern Canada and Alaska, Siberia and northern Scandinavia.
Structure:
Tundra vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens.
Scattered trees grow in some regions. The ecotone (or ecological boundary region) between
the tundra and the forest is known as the tree line or timberline. The rainfall is very limited in
this biome.
Relative Productivity:
The tundra has some of the lowest net primary productivity of any ecosystems, due mainly to
the cold and short growing season, and the infertile soils. Mean productivities range from 10400 g m-2 yr-1, with a mean of 140 g m-2 yr-1
Plant and Animal Adaptations:
The severe environment of the tundra zone has restricted which plants can survive here, and
molded many of them to cope with the extreme weather and climate. Most tundra plants are
short, getting no higher than bushes, even if they are trees. For example, some birches grow
only a few inches tall here. Others have decumbent stems (stems that grow horizontally
instead of vertically). A great number are evergreen. One might conclude that survival here
depends more on coping with the microclimate and physical extremes, rather than
competition.
Animals have many adaptations to survive in this harsh environment; Animals need shelter
and insulation in the Tundra. The animals here tend to have thicker and
warmer feathers and fur. Many of them have larger bodies and shorter arms, legs and tails
which helps them retain their heat better and prevent heat loss.
Named Examples:
High Arctic tundra, Interior Yukon-Alaska alpine tundra, Kalaallit Nunaat high arctic tundra
Deserts:
Climate:
Hot deserts have very hot summers that have temperatures that can even reach 45 °C (113
°F). Temperatures can even be very warm during winter. Cold deserts can have hot
summers as well, but the winters are usually very cold. They are usually at high altitudes and
can be drier than hot deserts.
Distribution:
Most of the world's hot deserts lie between 20° and 35° north and south of the equator. The
main temperate deserts are found in the middle latitudes.
Structure:
There are plenty of differences between the deserts of the world. Some deserts are made of
very fine, red sand, others consist of sand mixed with pebbles and rocks. The desert sand
started out as rock, but years of weathering by wind and water has created dunes in
the deserts.
Relative Productivity:
With the exception of large blooms of annuals, net primary productivity in most deserts is low
and extremely variable. There is a positive relationship between productivity and
precipitation, and since it doesn’t rain often in deserts, values can range from near 0 to 120 g
m-2 yr-1
Plant and Animal Adaptations:
Plants like cacti adapt to arid conditions in the desert by:
 thick, waxy skin to reduce loss of water and to reflect heat
 large, fleshy stems to store water
 thorns and thin, spiky or glossy leaves to reduce water loss
 spikes protect cacti from animals wishing to use stored water
 deep roots to tap groundwater
 long shallow roots which spread over a wide area
 plants lie dormant for years until rain falls
Animals like camels adapt to arid conditions in the desert by:
 long eye lashes, hairy ears and closing nostrils help to keep out sand
 thick eyebrows which stand out and shade eyes from the sun
 wide feet so they don't sink in the sand
 they can go without water for over a week because they can drink gallons in one go
 they can go months without food - they store fat in their humps
 body temperature can change to avoid losing water through sweating
 they are well camouflaged
 thick fur helps to keep them warm at night
Named Examples:
The Sahara Desert, The Arabian Desert, The Cobi Desert
Contrasting Pair C: Tropical Coral Reefs and Hydrothermal Vents
Tropical Coral Reefs
Climate:
Because of strict environmental restrictions, coral reefs generally are confined to tropical and
semi-tropical waters. Many grow optimally in water temperatures between 73° and 84°
Fahrenheit (23°–29°Celsius), but some can tolerate temperatures as high as 104°
Fahrenheit (40° Celsius) for short periods
Distribution:
Coral reefs need warm, shallow water to form. They form close to the equator near
coastlines and around islands throughout the world. Reef-building corals are scattered
throughout the tropical and subtropical Western Atlantic and Indo-Pacific oceans, generally
within 30°N and 30°S latitudes. A significant portion of the world's coral reefs are located in
Southeast Asia and near Australia.
Structure:
A coral reef is made of thin layers of calcium carbonate. Coral polyps form a living mat over
a calcium carbonate skeleton. Stony corals (or scleractinians) are the corals primarily
responsible for laying the foundations of, and building up, reef structures.
Relative Productivity:
Coral reefs are among the most productive ecosystems on the planet, with the primary
producers at the base of the food chain (including corals) supporting their complex food
webs. Through primary production, reef organisms covert carbon dioxide via photosynthesis
into energy (organic carbon) that they and other reef organisms use for food. Although light
provides the energy that fuels reef productivity, key nutrients such as nitrogen and
phosphorus are also required. Paradoxically, the warm tropical oceans where coral reefs are
found are generally very low in nutrients, raising questions about how these rich and diverse
ecosystems can be so productive in the oceans where they live.
Plant and Animal Adaptations:
Animals;
Due to the complex structures of coral reefs, with their many nooks, crannies, and hiding
spaces, fish have adapted a body structure to easily maneuver through the coral. In open
water fish have adapted bodies to swim faster, but within the coral reefs fish have adapted
bodies that are flat (like a pancake) and manoeuvrable. Also, the pectoral and pelvic fins
have switched places. This corresponds, and works with the flatter body. Fish found in coral
reefs also have bright colouring to help with mating or camouflage
Plants;
In order to collect the sunlight needed for photosynthesis, plants in coral reefs have larger
cells. Plants have also created many symbiotic relationships with other animals in order to
survive. Examples include:

Zooxanthellae lives inside the polyps in coral. In exchange the protection the coral
provides, the Zooxanthellae provides the coral with needed nutrients.

Sea grasses live in between the coral reefs, and they transfer nutrients to the coral.
Their roots are adapted to keep the plant in place during strong ocean
currents. When the sea grass dies it helps to create future plant growth.
Named Examples:
Great Barrier Reef, New Caledonia Barrier Reef, Red Sea Coral Reef
Hydrothermal Vents:
Climate:
Hydrothermal vents are the result of seawater seeping down through fissures in the ocean
crust. The cold seawater is heated by hot magma and comes back to the surface to form
the vents. Seawater in hydrothermal vents may reach temperatures of over 750 degrees
Fahrenheit (400 degrees Centigrade)
Distribution:
Hydrothermal vents tend to be distributed along the Earth's plate boundaries, although they
may also be found at intra-plate locations such as hotspot volcanoes. They are also known
to exist in the Pacific and Atlantic oceans. Most are found at an average depth of about
2,100 meters (7,000 ft) in areas of sea floor spreading along the Mid-Ocean Ridge system.
This ridge is an underwater mountain chain that snakes its way around the globe.
Structure:
Hydrothermal vents form at locations where seawater meets magma. The particles are
predominantly very fine-grained sulphide minerals formed when the hot hydrothermal fluids
mix with near-freezing seawater. These minerals solidify as they cool, forming chimneylike structures.
Relative Productivity:
On a researched estimate, deep-sea hydrothermal vents can produce more than 4,000 tons of
organic carbon each day, the building block of life. That is roughly the same amount of
carbon in 200 blue whales -- making these ecosystems among the ocean's
most productive on a per volume basis.
Plant and Animal Adaptations:
Organisms that live around hydrothermal vents don't rely on sunlight and photosynthesis.
Instead, bacteria and archaea use a process called chemosynthesis to convert minerals and
other chemicals in the water into energy. These specialized bacteria form the bottom of the
deep hydrothermal vent food web, and many animals rely on their presence for survival,
including deep-sea mussels, giant tube worms, yeti crabs, and many other invertebrates
and fishes.
Named Examples:
Beebe Hydrothermal Vent Field, The Endeavour Hydrothermal Vents
Contrasting Pair D: Temperate Bogs and Tropical Mangrove Forests
Temperate Bogs:
Climate:
In this biome, summer conditions become warmer and drier in continental regions and
winters become milder and wetter.
Distribution:
Bogs are widely distributed in cold, temperate climes, mostly in boreal ecosystems in the
Northern Hemisphere. They are present in the Southern Hemisphere aa well but are less
common there.
Structure:
A temperate bog is a wetland that accumulates peat, a deposit of dead plant material—
often mosses. They are characterised by a continuous carpet of sphagnum moss, a species-
poor herbaceous layer, low ericaceous, evergreen shrubs, and widely scattered and stunted
conifer.
Relative Productivity:
Temperate Bogs have a high relative productivity. This is due to the high net primary
productivity from the high number of producers in this biome like numerous shrubs and
varied trees.
Plant and Animal Adaptations:
Bogs have very few nutrients, making it difficult for many common plants to survive.
Carnivorous plants have adapted to ombrotrophic environments by not absorbing nutrients
from the surrounding water but instead, from insect prey.
Named Examples:
Western Siberian Lowlands in Russia.
Tropical Mangrove Forests:
Climate:
They are almost exclusively tropical, but are also seen in the subtropics. Mangroves are
intolerant of frost, but can tolerate air temperatures as low as 5°C. They are most closely
correlated with the seawater temperature.
Distribution:
Mangroves grow on 1/3 of tropical shores. They are also found in sub-tropical Africa, Asia,
and the southwest Pacific.
Structure:
Mangroves are trees or shrubs that grow in salty water in hot places like areas located in
the coastal intertidal zone.
Relative Productivity:
Biomass productivity of the mangrove species is relatively high among the mangrove
forests in the tropical and subtropical areas, showing a mean annual production of 7.1
Mg∙ha−1∙yr−1
Plant and Animal Adaptations:
Mangrove plants are able to survive in salt water as they have way to get rid of excess salt in
their bodies. Some mangrove plants get rid of excess salt in their bodies by excreting it on
their leaf surfaces.
Named Examples:
Bhitarkanika Mangroves Forest, The Pichavaram Mangroves