WORLD CLIMATES

& ECOSYSTEMS

What is an ecosystem?

An ecosystem is a natural environment and includes the flora (plants) and

fauna (animals) that live and interact within that environment. Flora,

fauna, humans and bacteria are the biotic or living components of the

ecosystem. Ecosystems are dependent on the following abiotic or non-

living components:

climate - the temperature and amount of rainfall are very important in

determining which species can survive in the ecosystem

soil - the soil type is important as this provides nutrients that will

support different plants

water - the amount of water available in an ecosystem will determine

what plants and animals can be supported

The biotic parts of the ecosystem have a complex relationship with the

abiotic components - changing one will lead to a change in the other.

Levels of ecosystems

Ecosystems vary in size, from extensive areas of rainforests or

grassland(known as biomes) to smaller areas of woodland and wetland and

down to under a stone.

Level Examples

MICRO Water droplet Under a leaf or stone

MESO(Middle) Fresh water pond Sand dune

GLOBAL(Biome) Tropical rain forest Tundra

Processes in an

ecosystem

Any ecosystem depends upon

two basic processes :

The flow of energy and,

The recycling of nutrients.

Energy flow

Each ecosystems is sustained by a flow of

energy through it. The main source of

energy is sunlight which is absorbed by

plants and converted by photosynthesis.

Energy then passes through the

ecosystem in the food chain (plants are

eaten by animals and animals are eaten by

other animals).

the ecosystem is an open system since

energy flow only one way with inputs,

flows and outputs.

Recycling of nutrients

Certain nutrients are continually circulated within the ecosystem and

so are part of a closed system.

Each cycle consists of plants taking up nutrients from the soil and the

nutrients are then used by plants and animals. When the plants die

they decompose and the nutrients are released in the soil.

WORLD BIOMES

Tropical rainforest

Tropical rainforests are renowned for their biodiversityand are found in a broad belt across the Equatorial regions of the Earth.

They are found in a belt across central and South America, Western parts of central Africa (it is too dry in the east), in parts of Southeast Asia such as Indonesia and even in Northern Australia.Within four square miles of tropical rainforest, you will find 1500 flowering plant species and 750 types of trees.

This biome is typified by plentiful rainfall, as

its name suggests.

Typical tropical rainforests receive over

2000mm of rainfall per year, but the rainfall

might not be EVENLY SPREAD. There will be

rainfall in each month, but some months are

wetter than others as shown on the climate

graph for Manaus below.

Temperatures are very even, with most

tropical forests averaging 27°C every day

with very little variation.

These 2 conditions allow for incredible plant

growth, allowing a very lush amount of

vegetation and of course consumers that feed

on the vegetation or primary producers.

Tropical soils are very deep, some of the deepest in

the world. This includes the Latosol, a typical

tropical forest soil.

Tropical soils can be several metres thick BUT are

often very nutrient poor as you go down through the

soils. This is because the rainwater washes out or

LEACHES the nutrients and minerals out of the soil.

Soils are often red in colour as they are rich in iron.

It is a huge system of NUTRIENT CYCLING that allows

the vegetation to grow. This is a good example of the

INTERDEPENDENT (where things rely upon each

other) nature of the forest. As vegetation dies it is

quickly decomposed by insects, bacteria and

fungi. This releases nutrients into the surface of the

soil which is taken up quickly by the plants.

Water is also recycled within tropical forests. The roots of plants

take up water from the ground and the rain is intercepted

(caught and trapped) as it falls – the vast majority of it in the

canopy.

As the rainforest heats up during the day, the water evaporates

into the atmosphere and forms clouds to make the next day's

rain. This is convectional rainfall. The forests also protect the

soil from being washed away or eroded by the heavy tropical

rains.

The forest is packed full of plants and it is a genuine competition

between plants for light and space. The rainforest is layered or

stratified, as plants try to take advantage of what space and light

there is.

Deforestation

The clearing of trees in tropical rainforest areas

has huge environmental impacts. Scientists are

very concerned about the loss of biodiversity

from such clearances.

Even though topical forests cover only twelve

percent of the land area of the Earth, they are

home to between 50 and 90 percent of the

world's species. It is thought that we lose one

species a day because of deforestation.

Rainforests are a vital source of medicines,

many originally used by indigenous people. An

example includes Reserpine, a drug which can be

used to treat people with high blood pressure.

All of the land clearances mentioned above remove forest cover. If

the forest is allowed to recover, which it rarely is, the forest is rarely

as it was before.

Hardwood trees take many years to grow so can be difficult to

replace for example.

Soils are damaged as the nutrient cycle is destroyed, whilst soils are

also exposed to rainfall so get eroded and that clogs up rivers with

sediment.

The loss of forest cover also affects the water cycle in terms of

evaporation, flooding and precipitation.

Animal habitat is also lost when trees are cut down.

If indigenous people are viewed as part of the environment they are

also affected. Their numbers have declined and today the Brazilian

census reveals that there are 817,000 indigenous peoples.

There are many ECONOMIC POSITIVES of developing rainforests.

Improving transportation through the forest means easier access to raw materials like

minerals and timber.

Forest resources can then be transported away and sold, especially when roads are

paved.

These large scale farms bring money into the country and provide food and jobs for the

country’s growing population. However, the profits from such large-scale farming and

selling resources often go to large companies who set up in the rainforest.

Small scale farmers can also lose out.

Finally, tropical rainforests often have Mineral Deposits including bauxite, iron ore,

manganese, gold, silver and diamonds. These can be exploited and sold.

The money from exploiting resources can then be used to improve hospitals and

education.

• As can be seen deforestation increased from 1700 to 1979 in tropical areas, and although deforestation is still

occurring, the AMOUNT of deforestation is in decline.

• However, in some tropical countries the rate of deforestation is increasing rapidly as those countries use their

forest resources. Indonesia has seen the greatest increase, as they replace forests with palm oil

plantations. This has threatened the Orang-utan.

CASE STUDY : Amazon deforestation

The Amazon is the largest tropical rainforest on

Earth. It sits within the Amazon River basin,

covers some 40% of the South American continent

and as you can see on the map below includes

parts of eight South American countries: Brazil,

Bolivia, Peru, Ecuador, Colombia, Venezuela,

Guyana, and Suriname. The actual word “Amazon”

comes from river.

The Amazon caught the public’s attention in the 1980s when a

series of shocking news reports said that an area of rainforest

the size of Belgium was being cut down and subsequently burnt

every year.

The Amazon helps a Newly Emerging Economy(NEE), Brazil, to

make money.

They build roads into the forest, logging firms then go in and

take out valuable hard woods such as mahogany and cedar,

worth thousands of pounds in richer economies like Europe.

Then farmers, often cattle ranchers from big companies, burn

the rest to make way for cattle pasture.

Deforestation is also worse in the South and South East of the

Amazon basin, closer to major centres of population in Brazil.

Causes of deforestation

Subsistence and commercial farming –

subsistence farming is where poor farmers occupy plots of the forest to

grow food to feed themselves and their families.

They clear forest and then burn it, hence the name slash and burn.

They grow crops until the soil is exhausted and then move on. This

contributes to deforestation but not as much as commercial farming

(Farming to sell produce for a profit to retailers or food processing

companies).

The Brazilian region of Mato Grosso was affected by deforestation in the

1980s and 1990s. 43% of rainforest losses were in this region, and area

almost ½ the size of France. It has been replaced by fields for grain and

cattle.

This has allowed Brazil to overtake Australia as the largest exporter of

beef in the world. The land is also flat and easy to farm. It also has

high temperatures and lots of rainfall.

Logging

The timber is used to build homes, furniture, etc. and the pulp is used

to make paper and paper products.

Selective logging is selective because loggers choose only wood that is

highly valued, such as mahogany. Clear-cutting is not selective.

Loggers are interested in all types of wood and therefore cut all of the

trees down, thus clearing the forest, hence the name- clear-cutting.

Road building

trees are also cleared for roads. Roads are an essential way for the

Brazilian government to allow development of the Amazon

rainforest. However, unless they are paved many of the roads are

unusable during the wettest periods of the year. The Trans

Amazonian Highway has already opened up large parts of the forest

and now a new road is going to be paved. This is making the

untouched forest along the route more accessible and under threat

from development.

Mineral extraction

forests are also cleared to make way for huge mines. The Brazilian

part of the Amazon has mines that extract iron, manganese, nickel,

tin, bauxite, beryllium, copper, lead, tungsten, zinc and gold!

Energy development

focused mainly on using Hydro Electric Power, and there are 150 new

dams planned for the Amazon alone.

The power in the Amazon is often used for mining.

Dams displace many people and the reservoirs they create flood large

area of land, which would previously have been forest.

They also alter the hydrological cycle and trap huge quantities of

sediment behind them.

The huge Belo Monte dam started operating in April 2016 and will

generate over 11,000 Mw of power.

Settlement & population growth

Many people are migrating to the forest looking for work associated with the natural

wealth of this environment.

Settlements like iron ore mining towns, have grown rapidly, destroying forest and

replacing it with a swath of shanty towns.

The population has grown from 154,000 in 2010 to 220,000 in 2012. The Brazilian

Amazon’s population grew by a massive 23% between 2000 and 2010, 11% above the

national average.

Impacts of deforestation

Every time forest is cleared species are lost – so we lose BIODIVERSITY

Climate Change - Burning the forest releases greenhouse gasses like CO2.

This contributes to the warming of our planet via climate change and global

warming. In addition, the loss of trees prevents CO2 being absorbed, making

the problem worse.

Economic development –Brazil has huge foreign debt and lots of poor people

to feed, so they want to develop the forest. May Brazilians see deforestation

as a way to help develop their country and improve people’s standard of

living.

Soil erosion - the soils of the Amazon forest are not fertile and are quickly

exhausted once the forest is cleared. The farmers now artificially fertilise

the soil when in the past the nutrient cycle would have done this naturally.

In addition, the lack of forest cover means that soils are exposed to the

rainfall. This washes huge amounts of soil into rivers in the process of soil

erosion.

Sustainable Forest management

Sustainable uses of the rainforest are uses that allow current generations to make a

living from the forest without damaging the forest for future generations to use. It is

clear that many of the current uses of the forest just destroy it, with massive long term

impacts.

Selective logging and replanting,

Selective logging is more sustainable than clear-cutting because other trees and

plants do survive in the logging process and over time can allow the forest to

recover. However, it does have major drawbacks. Although single trees are felled

because they are valuable, other trees can be damaged in the process. This is

because a felled tree can damage other trees as it falls to the ground once felled.

Also, loggers need to access the wood, so have to clear come forest to make way for

machinery.

Sustainable Forest management

Ecotourism, conservation and education

Conservation is all about the protection, preservation, management, or

restoration of tropical forests and the ecological communities that inhabit

them. This includes the Amazon Region Protected Areas Program (ARPA),

where the WWF work with the Brazilian government to protect parks

covering 150million acres of forest.

Ecotourism is environmentally friendly tourism where;

the people involved seek to protect the environment as much as possible

there is education of the visitor

some of the profits go back into conserving the rainforest environment

the tourism is small scale with low visitor densities

local people are employed and involved

The tourist stay in wooden huts, there is limited electricity, waste is

dealt with on site and the food is sourced locally. All of the tour guides

are local.

Sustainable Forest management

International agreements about the use of tropical hardwoods

There are also international agreements on the uses of tropical hardwoods and logging. The International Tropical Timber Agreement was set up in 2006 to "promote the expansion and diversification of international trade in tropical timber from sustainably managed and legally harvested forests and to promote the sustainable management of tropical timber producing forests".

71 countries have signed up to the agreement sponsored by the United Nations.

Debt reduction

Debt reduction or conservation swaps offer an alternative to poorer countries to the reckless exploitation of their natural wealth.

These swaps basically see poorer countries have portions of their debts wiped out or paid for by richer nations or charities of richer nations in exchange for promising to protect or CONSERVE large parts of their natural environment. In 1984 the World Wildlife Fund came up with the idea of conservation swaps and in 1987 the first was launched in partnership between the Government of Bolivia and Conservation International (CI) for US$ 650000 which protected 3 natural areas. Many countries have since followed, including the Philippines, Sudan, Zambia, Ecuador and Uganda.

Savanna grassland Savannas - also known as tropical grasslands - are

found to the north and south of tropical

rainforest biomes.

The largest expanses of savanna are in Africa,

where much of the central part of the continent,

for example Kenya and Tanzania, consists of

tropical grassland. Savanna grasslands can also be

found in Brazil in South America.

Savanna regions have two distinct seasons - a wet

season and a dry season. There is very little rain

in the dry season. In the wet season vegetation

grows, including lush green grasses and wooded

areas.

As you move further away from the equator and its

heavy rainfall, the grassland becomes drier and

drier - particularly in the dry season. Savanna

vegetation includes scrub, grasses and occasional

trees, which grow near water holes, seasonal

rivers or aquifers.

Savanna grassland

Plants and animals have to adapt to the long dry periods.

Many plants are xerophytic - for example, the acacia tree with its small, waxy leaves and thorns. Plants may also store water, for example the baobab tree) or have long roots that reach down to the water table.

Animals may migrate great distances in search of food and water.

The graph below shows average monthly temperatures and rainfall levels in the savanna region of Mali. Notice how the temperature and rainfall patterns relate to each other - the hottest temperatures come just before heavy rainfall, and the coolest time of the year comes just after the rains. This pattern is typical of savanna climates.

Savanna soils

Savanna grassland soils are not very fertile.

The nutrients in the soil are found near the

surface as they come from decayed organic

matter (vegetation) from the previous growing

season.

This organic matter decays rapidly due to the

high temperatures.

Soils tend to be red in colour due to their high

iron content.

The diagram shows the different horizons, or

layers, of soil in savanna grassland. Plant roots

cannot penetrate the hard 'pan' layer in the B-

horizon, or subsoil. This restricts vegetation

growth.

The Serengeti plains of Tanzania are probably the best known African savanna.There are two main types of vegetation in the Serengeti. Grasses cover the vast open plains of the southeast while in the central region, acacia plants are more common. The Serengeti is rich in wildlife - including giraffes, zebras, elephants, lions and over 2 million wildebeest. Many of the animals found on the Serengeti can be found nowhere else in the world.

Desertification

Desertification is the process by which land becomes drier and

degraded, as a result of climate change or human activities, or both.

As population increases they increase the numbers of animals they

keep, such as goats, which eat more vegetation. They also farm the

land more intensively, which extracts nutrients and removes the

natural vegetation. People also collect more firewood to keep warm

at night or for cooking.

Climate change is making temperatures hotter and rainfall less

reliable and more variable. All of these things reduce the amount of

natural vegetation.

no plants or leaves to intercept rain and soil is left exposed to hot

sun so the sun bakes the soil and it cracks. When it rains, the

rainwater runs over the surface of the soil rather than soaking in

which means that soil can often be washed away.

This means that the soil is degraded; losing fertility and structure.

This completes the cycle, as even less vegetation can be supported

and the environment declines further.

Desertification

Causes of desertification include:

Removal of vegetation cover.

Overgrazing.

Uncontrolled fuel wood collection.

Unsustainable farming practice and loss in fertility of soil.

Excessive tree felling.

Effects of desertificationDesertification is a serious issue that affects over 1

billion people around the world. In 2014 the UN stated

that 20million people in the Sahel region of Africa faced

hunger and required $2 billion in food aid due to

desertification.

The loss of vegetation can cause severe soil erosion

as nutrients in the soil get washed or leached away

leaving soil infertile.

The loss of vegetation also means that there has been

damage to animal’s habitats.

loss of species affects the availability of local

medicines.

Population pressure has also stopped people moving

animals from place to place as they traditionally did

and using settled agriculture. This settled agriculture

means that people farm too intensively leading to

regular crop failure.

Effects of desertification

People also draw more water out of the soil

for irrigation. Together with the drying of

the soil this leaves deposits of salt-

salinisation and means crops can’t be

planted.

Lack of food and water can also mean

farmed species such as cattle can die of

starvation.

People have to migrate out of these

desertified areas and often end up in

shanty towns at the edge of big cities or in

refugee camps. Food aid can be flown in

but people can become reliant upon this.

However, famines do happen and 250,000

people died in the Sahel drought of 1968 to

73.

The Sahel

The Sahel is semi-arid, receiving between 250 and 450 mm of rainfall in total in

an average year, however it only falls in one or two months.

Since the 1970s, the Sahel has experienced drought conditions on a regular basis.

This is down to physical and human factors:

Solutions to desertificationPrevention is much more cost-effective than rehabilitation. Desertification can be reduced by adopting the following strategies:

Planting more trees - the roots of trees hold the soil together and help to reduce soil erosion from wind and rain.

Improving the quality of the soil - this can be managed by encouraging people to reduce the number of grazing animals they have and grow crops instead. The animal manure can be used to fertilise the crops grown.

Water management - water can be stored in earth dams in the wet season and used to irrigate crops during the dry season. This is an example of using appropriate technology to manage water supplies in the desert environment.

Magic stones (or bunds) are circles of stones placed on the ground to hold water on the soil rather than letting it run quickly over the surface.

Drip irrigation is where water drips slowly onto the ground from pin-sized holes in a hose lying on top of the soil. This minimises water loss, maximises effectiveness and can be delivered via a solar pump.

A project focussing on Acacia or gum trees

is trying to help. The FAO and forestry

service have provided nursery’s to grow

seeds and seedlings. The locals were also

taught how to sow and plant the Acacia

trees, and how to extract and market the

gum they produce.

NGOs and international bodies

Most of the people affected by desertification are poor and do not have

the resources to combat desertification.

Encouraging farmer cooperatives, non-governmental organisation

(NGO) projects and internationally-funded schemes gives assistance to

local farmers.

The Mediterranean (Chaparral)

The Mediterranean biome has developed between 30-40°latitudes in both the hemispheres in

the western parts of the continents.

This biome includes the European lands bordering the Mediterranean Sea, central and southern

California, central Chile, north-western coastal lands of Africa bordering the Mediterranean

Sea and the far southwestern part of South Africa and the coastal zones of western and

southern Australia and the Asiatic coastal lands bordering the Mediterranean Sea (western

Turkey, Syria, western Israel and Lebanon).

Mediterranean climate

The Mediterranean climate has three typical

characteristic features which give sclerophyll

characteristics to the vegetation of this biome

e.g.:

Winters are cool but wet whereas summers

are dry, most of the annual rainfall is received

during wet winter months;

Summer season is warm and dry whereas

winters are moderately cool; and

There is sufficient sunlight throughout the

year but summer is more sunny.

These characteristic climatic features of the

Mediterranean climate have developed because of

the seasonal shifting of the pressure and wind

belts due to northward and southward migration of

the sun.

Mediterranean climate

The average temperature during cool winter season ranges between 5°C and 10°C

whereas mean summer temperature varies from 20°C to 27°C and thus the annual

range of temperature becomes 15°C to 17°C or even more.

Mean annual rainfall ranges between 370mm and 650mm, the most portions of which

is received during winter season. The winter rainfall is received through the cyclonic

storms associated with the westerlies.

The summer season is almost dry. Thus, the deficiency in soil- water content

during dry summer season prevents vegetation growth.

Vegetation community

Though the Mediterranean regions are

widely scattered over different continents,

there is a broad generalization in the

overall structure and composition of the

vegetation community of all the regions of

the Mediterranean biome.

The structure of the Mediterranean

vegetations is such that they can withstand

the aridity of the summer season.

The leaves have developed sclerophyllous

characteristics wherein they are stiff and

hard and the stems have thick barks.

Mediterranean vegetation community

consists of a variety of mixed evergreen

forests (in the coastal lands immediately

bordering the seas and the oceans) to

woodland, dwarf forest and scrubs.

Vegetation community

The shrubs are differently named in the various parts of the Mediterranean biome on the basis of local names e.g., maquis or garrigue in southern Europe, chaparral in California, fymbos or fymbosch in south Africa and mallee scrub in Australia.

some plants have extensive root systems with strong tap root which extends even into the consolidated parent rocks (such as the roots of almond);

some plants have such root systems which develop above the ground as well as quite deep inside the ground (such as the root of chamise);

some plants have bulbous or tuber roots (such as the geophyte plants, e.g. different types of flowers like dahlia) etc.

Animal community

Like vegetation, there is also regional variation in the animal communities of the various parts of the Mediterranean biomes of the world. The Mediterra-nean biomes of California and Chile are characterized by more or less similar animal species. There are numerous animals in these two regions because of abundant supply of food from the good cover of various types of shrubs.

Mammals are now dominated by ground squirrels, wood rats and mule deers. Many of the predator species like wolf and mountain lion. Others like grizzly bear have now become rare species because of increasing pressure of man on the Mediterranean vegetation.

The other important animals include several species of rodents such as rabbits and rats, other predators such as lizards, snakes, and several types of raptorial birds like falcons, hawks etc.

The Australian Mediterranean biome is characterized by marsupials which include kangaroos mainly western grey kangaroo. There are numerous varieties of wallaby and mice.

Man and the Mediterranean

Man has directly and indirectly adversely affected the flora and fauna

of the Mediterrnean biomes.

Fire, both natural and man- induced, is a normally annual

occurrence in the Mediterranean biome. The natural forest fires

occur through lightning whereas man burns the grasses to get

luxuriant growth next season. There is a common practice to burn

the vegetation each year or after two or three years after heavy

grazing and browsing by sheep and goats.

Most of the plant species of the Mediterranean biomes have

become fire-resistant and are now well adapted to fires - after

burning the growth of new branches, shoots and leaves occurs.

Some seeds germinate more quickly and properly after fires.

Burning of vegetation transforms the organic matter into ashes

and thus facilitates the mineralisation of organic matter and

ultimately makes the mineralised organic matter available to plant

roots.

Fire destroys poisonous compounds secreted by plant roots.

Tropical desert climate

The tropical desert is an environment of extremes:

it is the driest and hottest place on earth.

rainfall is sporadic and in some years no

measurable precipitation falls at all.

the terribly dry conditions of the deserts is due

to the year-round influence of subtropical high

pressure and continentality.

Deserts are typically found in continental

interiors of the subtropics and on the lee side

of mountains in the midlatitudes.

Vast deserts cover much of north Africa (The

Sahara), Saudi Arabia to Iran, Pakistan and

western India. Tropical deserts are found in

Baja California and interior Mexico in North

America.

Tropical desert climateTemperature

The tropical desert has the highest mean annual temperature of any climate on Earth.

The high temperatures are a result of the high sun angles throughout the year and having the highest percentage of sunshine of any climate.

No month has an average temperature below 18oC (64.4oF) and many places have consecutive average monthly temperatures in the mid 30os Celsius (90oF).

Daytime temperatures can reach 50oC (120oF) at low elevation inland deserts.

The sky in the tropical desert remains cloud-free due to the subsiding air of dominant high pressure resulting in large amounts of insolation.

The cloudless skies during the day lets insolation in, but also lets much heat out at night. Without the absorptive blanket of clouds, longwave radiation emitted from the Earth readily escapes to space, chilling the night time desert air.

The high energy input during the day and large loss at night results in an extremely large daily temperature range.

Tropical desert climate

Precipitation in the tropical desert is very

irregular and unreliable.

Low latitude deserts average less than 25 cm (10

in) in a year. An entire year's worth of rain may fall

in one downpour.

The continental location of many tropical deserts

places them far from a source of moisture, the

ocean. Combine continentality with the strong

subsidence of the subtropical high and you have

one of the driest places on earth.

In the tropical desert the only substantial source of

surface water other than exotic streams is

an oasis, where the groundwater table is near

the surface.

Adaptations

The extreme climate of the desert ecosystem means that plants and animals have had to adapt to survive. Vegetation has had to adapt to the extreme temperatures, lack of water and high rates of evaporation.

The main adaptations are:

Vegetation has leaves that are very small (and only grow after it rains) or have no leaves at all. This helps to reduce water loss;

Plants either have long root systems spread out wide or go deep into the ground to absorb water;

Plants have short life cycles. They germinate following rainfall, grow, flower and die within a short space of time e.g. one year. This helps them avoid drought;

Some plants have spines to discourage animals from eating plants for water and reduce water loss through transpiration;

Many plants are slow-growing – this requires less energy. The plants don’t have to make as much food and therefore do not lose as much water.

Some plants are succulents and store the water in their leaves, stems or roots. An example of this is the cactus.

Adaptations

The ability to adapt to arid conditions can mean the difference

between life or death for animals and plants that live in the desert.

Some animals burrow deep underground in the heat of the day, lie

in the shade until late afternoon or early evening, or have evolved

salt glands, which allow their bodies to secrete salt but not sweat

so they retain water.

At night, the desert comes alive. A universal adaptation of desert living

begins with an upside-down day.

Instead of sleeping at night, nocturnal animals sleep during the

hottest part of the day, only to take up their business of hunting

food during the graveyard shift.

By sleeping in the day, usually in the shade beneath an outcropping

of rocks, in a burrow dug into the cool underground, they preserve

their body’s water. This applies to mammals, insects and reptiles of

the desert.

Camels

Camels evolved and physically adapted to hot desert days and

cold desert nights in multiple ways.

The camel’s hump doesn’t store water, as many people think;

it stores fat. The hump’s fat provides the camel with a source

of energy for long desert journeys. As the fat is used, it

creates water as a by-product, which adds to the animal’s

supply of water through its bloodstream.

Camels don’t sweat as much as humans do, and at night, their

metabolism slows way down to help preserve water as well.

The heavy fur on their bodies acts as an insulator against heat

as well as a blanket against a desert’s extreme winter cold.

With extra-dry nasal passages and large nostrils closed and

opened at will, camels condense moisture by cooling incoming

air.

Because of all the desert sand that gets blown about, camels

have three eyelids, and long curly eyelashes that protect

their eyes from the sand.

Monsoon climate

A monsoon is a seasonal

change in the direction

of the prevailing, or

strongest, winds of a

region. Monsoons cause

wet and dry seasons

throughout much of

the tropics. Monsoons are

most often associated with

the Indian Ocean.

Monsoons always blow

from cold to warm

regions. The summer

monsoon and the winter

monsoon determine

the climate for most of

India and Southeast Asia.

Summer monsoon

The summer monsoon is associated with heavy rainfall.

It usually happens between April and September.

As winter ends, warm, moist air from the southwest Indian Ocean

blows toward countries like India, Sri Lanka, Bangladesh, and

Myanmar.

The summer monsoon brings a humid climate and torrential rainfall

to these areas.

India and Southeast Asia depend on the summer monsoon.

Agriculture, for example, relies on the yearly rain. Many areas in

these countries do not have large irrigation systems surrounding

lakes, rivers, or snowmelt areas. Aquifers, or supplies of underground

water, are shallow. The summer monsoon fills wells and aquifers for

the rest of the year.

Rice and tea are some crops that rely on the summer monsoon.

Dairy farms, which help make India the largest milk producer in the

world, also depend on the monsoon rains to keep cows healthy and

well-fed.

Summer monsoonIndustry in India and Southeast Asia also relies on the summer monsoon.

A great deal of electricity in the region is produced by hydroelectric power plants, which are driven by water collected during the monsoons. Electricity powers hospitals, schools, and businesses that help the economies of these areas develop.

When the summer monsoon is late or weak, the regions economy suffers.

Fewer people can grow their own food, and large agribusinesses do not have produce to sell.

Governments must import food.

Electricity becomes more expensive, sometimes limiting development to large businesses and wealthy individuals.

The summer monsoon has been called India’s true finance minister.

Summer monsoon

Heavy summer monsoons can cause great damage.

Residents of such urban areas as Mumbai, India, are

used to the streets flooding with almost half a meter

(1.5 feet) of water every summer. However, when the

summer monsoon is stronger than expected, floods

can devastate the region. In cities like Mumbai,

entire neighborhoods can be drowned. In rural

areas, mudslides can bury villages and destroy

crops.

In 2005, a strong monsoon devastated western India.

As the summer monsoon blew in from the southwest,

it first hit the state of Gujarat. More than 100

people died. Then, the monsoon rains hit the state of

Maharashtra. Flooding in Maharashtra killed more

than 1,000 people. On July 26, 2005, the city of

Mumbai, Maharashtra, received almost a meter (39.1

inches) of rain.

Winter monsoon Winter monsoons are less powerful than

summer monsoons in Southeast Asia, in

part because the Himalaya Mountains

prevent much of the wind and moisture of

the monsoons from reaching the coast.

The Himalayas also prevent much of the

cool air from reaching places like southern

India and Sri Lanka, keeping them warm all

year. Winter monsoons are sometimes

associated with droughts.

Not all winter monsoons are dry, however.

Unlike the western part of Southeast Asia,

the eastern, Pacific coast of Southeast Asia

experiences its rainy season in the winter.

The winter monsoon brings moist air from

the South China Sea to areas like Indonesia

and Malaysia.