Unit 5 ecosystems

1

SCIENCE 5. UNIT 5. ECOSYSTEMS. C.E.I.P. SANTA ANA (Madridejos)

CONTENTS:

1.– What an ecosystem is, and its components.

2.– Types of ecosystems: aquatic / terrestrial.

3.- Relationships between living beings: a.- Feeding relationships.

b.- Between the same species and different species. 4.– Human activities and ecosystems:

a.– Problems.

b.– Solution: sustainable development.

Snake versus chameleon

ECOSYSTEM is a community of organisms

interacting with each other and with the envi-

ronment on a place.

.– ecosystem .– biotic part .– abiotic part .– aquatic .– terrestrial .– freshwater

1.– ECOSYSTEMS AND COMPONENTS.

An ecosystem is a community or organisms (animal,

plants, microbes…) interacting with each other and

with the environment (air, water, soil, humidity, tempe-

rature…) on a place.

An ecosystem can be enormous (a desert,an ocean…),

or very small (a pond).

COMPONENTS OF AN ECOSYSTEM:

1.1– (Biotic) Living things: are animals, plants… that

live in that place. There are different species living to-

gether in an ecosystem.

1.2.– (Abiotic) Non-living things: are rocks, water, air

from that place, and the atmospheric conditions

(humidity, temperature…). These characteristics make

what species can exist in the ecosystem (desert, fo-

rest…)

1.3.– Relationships between living things and non-

living things. Every organism depends on the rest of

them.

When these relationships don’t change, the ecosystem is

balanced and it doesn’t change. But if there are impor-

tant changes in these relations (for example if there are

more consumers, or predators…), the ecosystem will

change.

Different species in an ecosystem

Plague of rabbits in Australia (1.961)

1

2

2.– TYPES OF ECOSYSTEMS.

There are many different types of ecosystems:

Aquatic and terrestrial.

2.1.– AQUATIC ECOSYSTEMS:

A.– Freshwater ecosystems: in rivers, lakes… B.– Marine ecosystems: in the sea or oceans.

COMPONENTS of an ecosystems are:

.– Biotic part or living things: (animals, plants…)

.– Abiotic part or non-living things: (water, temperature…)

.– Relationships between living things and the environment.

3

4

3

5

2

USEFUL WORDS:

.– temperature .– precipitation .– vecinity to the sea .– altitude .– latitude

.– tropical zone .– temperate zone .– polar zone .– tropical rainforest .– savanna

Ecosystems in the TROPICAL ZONE:

.– Tropical rainforest.

.– Savanna.

.– Hot desert.

2.2.– TERRESTRIAL ECOSYSTEMS.

There are some factors with a great influence on types of ecosystems:

.– Atmospheric factors: temperature, precipitation…

.– Geographical factors: vicinity to the sea, altitude, latitude (distance

from the Equator)...

A.2.- Savanna, with two seasons (a dry and a wet

seasons). There are lots of grass and bushes. There

are a great variety of wild mammals. It’s near the

tropics.

A.1.– Tropical rainforest. Near the Equator. It’s very

hot with lots of precipitations. It’s a thick forest with a

great variety of life.

We can divide the Earth in different climate zones:

A.– Tropical zone: near the Equator (high temperatures)

B.– Temperate zones: (warm temperatures)

C.– Polar zones: in the North & South poles (very cold).

The climate zones on Eath are: .– One tropical zone.

.– Two temperate zones.

.– Two polar zones.

Terrestrial ecosystems depend on the climate zones.

A.- TROPICAL ZONE:

Climate zones on Earth

A.3.- Hot desert, with very high temperature during

the day, and very low during night. It is very dry, so

there are scarce vegetation adapted to live with only

a bit of water.

6

7

8

9 10

3

.– Mediterranean ecosystem .– deciduous forest .– coniferous forest .– cold desert

.– tundra .– producers/autotrophic .- consumers/heterotrophic .– decomposers

B.– TEMPERATE ZONES:

B.1.– Mediterranean ecosystem:

It’s cool in winter and hot and very dry during summer.

Trees, bushes and grass are adapted to dry summers.

Near the Mediterranean sea and other places.

Ecosystems in the TEMPERATE ZONE:

.– Mediterranean ecosystem.

.– Deciduous and coniferous forests.

B.2.– Deciduous and coniferous forests:

Deciduous trees lose their leaves in Autumn.

Coniferous trees don’t lose their leaves in Autumn.

With cold winters and mild summers, with a high

level of precipitation. They are near oceans.

C.– POLAR ZONES:

Tundra and cold deserts have got very cold temperatures, where only a few animals and plants can live

because of the climate. They are near the poles.

Tundra Cold desert in the North Pole

3.– RELATIONSHIPS BETWEEN LIVING BEINGS.

3.1.– FEEDING RELATIONSHIPS, or FOOD CHAIN.

Living organisms interact with other parts of ecosystems (abiotic and biotic parts) to obtain nutriens.

There are three kind of beings depending on the way they get their food:

Ecosystems in the POLAR ZONES:

.– Tundra.

.– Cold deserts.

A FOOD CHAIN is formed by:

.– Producers or autotrophic organisms: plants, algae...

.– Consumers or heterotrophic organisms: herbivores, carnivores &omnivores.

.- Decomposers.

Mediterranean ecosystem

Deciduous forest

12 13

15 14

16

11

4

USEFUL WORDS:

.– Family .– gregarious association .– society

A.- Producers (plants, algae, bacteria): they pro-

duce their own nutrients from non–living things:

water, minerals, sunlight, gases… They are called

autotrophic organisms.

B.- Consumers (animals): get nutrients from oth-

er living beings, (plants or another animals). They

are called heterotrophic organisms.

There are different types:

.- Hervibores: they eat plants.

.- Carnivores: they eat other animals:

.- Omnivores: they eat plants, animals…

C.- Decomposers (bacteria, fungi, worms…): get their food from dead organisms, excrement, and non-

living organic compounds.

The Chain Food must be balanced, in other case the ecosystem will change.

RELATIONSHIPS BETWEEN ORGANISMS:

.– Organisms of the same species:

a.– Families.

b.– Gregarious associations.

c.– Societies.

.– Organisms of different species:

a.– Mutualism.

b.– Commensalism.

c.– Parasitism.

d.– Predation

17

3.2.– RELATIONSHIPS BETWEEN ORGANISMS.

Living beings interact with other living beings in order to

get food, to get a space for hunting… Species interact every

day. That interaction is a vital part of how organisms deve-

lop and change over time.

3.2.1.– ORGANISMS OF THE SAME SPECIES.

Sometimes organisms live in groups with other organisms

of the same species, for protection, to get food…

There are different types of groups:

a.– Families: are small groups of living beings related one

each other (they are parents, babies…), to protect, feed and

reproduce between them. Some individuals are dominant

over others (Ex: lions, wolves…)

b.– Gregarious associations: are groups of living beings

that live together, but they aren’t related each other.

(Examples: flocks of birds, flocks of zebras…)

C.– Societies: are groups of living beings in which there is a

level of organization with their work distributed. They are

specialized for different roles. (Ex. bees, ants…) There is a

Queen, soldiers, workers...

Family of lions

Gregarious association: wildebeests

Society of bees: Queen & workers

22

21

20

18 19

5

USEFUL WORDS:

.– mutualism .– commensalism

.– parasitism .– parasite .– host

.– predation .– predator .– prey

.– exploit .– natural resources

3.2.2.– ORGANISMS OF DIFFERENT SPECIES:

There are different relations between organisms of different species. These relations can benefit to both of

the species, only to one of them, or even they can be very dangerous.

a.– Mutualism: is an interaction in which both species benefit from the rela-

tionship. Species need each other.

Example: Bees get pollen from flowers, and at the same time flowers are po-

llinated by bees.

b.– Commensalism: is an interaction in which one species

benefits and does not affect the other one.

Example: Lions and vultures. Vultures eat the rest of preys

hunted by lions.

24

23

c.– Parasitism: is an interaction in which one species (the parasite)

benefits from another species (the host), while harming the host in the

process.

Example: Lice on mamals or humans. Lice feed blood from the host’s.

25

D.– Predation: is an interaction in which one species

(predator) kills and eats to another species (prey).

Example: A falcon (predator) kills and eats a pigeon

(prey).

26

4.- HUMAN ACTIVITIES AND ECOSYSTEMS:

Human beings are part of the ecosystems where we live.We are

consumers, so we exploit natural resources around us: ani-

mals, plants and natural resources. On the other hand, we inter-

act in a negative way with the environment.

Polluted human landscape

27

6

4.A.– PROBLEMS:

Human beings adapted to different environments, and we are changing them. Nowadays, we are millions

and millions of people, so we need a lot of natural resources. So there is an overexploitation of these re-

sources, and as a result many different problems:

A.1.– Pollution of air, water and land, produced by the use of

non-renewable energies (oil, coal, natural gas or nuclear power)

in industry, transport, production of electricity.

A.3.– Extinction of species, (animals and plants), produced by

the change in ecosystems, by deforestation, fires, agriculture, big

constructions…

Lots of different species are in danger of extinction, and every

day many of them are disappering from our planet.

A.2.– Gobal warming and greenhouse effect are changing our

climates on Earth, so ecosystems are changing too fast, and this

affect to plants, animals and even the human beings.

4.B.– SOLUTIONS:

The solution to these type of problems is the sus-

tainable development.

We must contribute to preserve our environment

with different actions:

Sustainable development is the development that

meets needs from present life with needs from futu-

re generations, to preserve our world.

B.1.– Reduction of pollution. We must change the use of

energy into renewable energies, like wind, water, solar

power… that don’t pollute and we can use them for ever.

B.2.– Stop the global warming, mainly reducing pollu-

tion and some gases that affect to the quality of air.

B.3.- Preservation of biodiversity, in order to

maintain original ecosystems where animals and

plants can live and reproduce.

Create natural parks, and avoid overexploitation,

and deforestation.

Air pollution

Iberian Lynx is in danger of extinction

Wind power in Madridejos

30

Spanish Imperial Eagle

is protected by law

B.4.– What we can do:

1.– Save energy at home.

2.– Reuse, reduce and Recycle (paper, glass,

batteries…)

3.– Take care of nature (keep clean the coun-

tryside) when you visit the mountains…

4.– Others

28

33

29

34

31 32

.– pollution .– global warming .– extinction .– greenhouse effect

.– sustainable development .– renewable / non-renewable energies .– biodiversity