Unit 5 ecosystems

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SCIENCE 5.

C.E.I.P. SANTA ANA (Madridejos)

UNIT 5. ECOSYSTEMS.

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.

ECOSYSTEM is a community of organisms interacting with each other and with the environment on a place.

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, temperature…) on a place.

An ecosystem can be enormous (a desert,an ocean…), or very small (a pond).

Snake versus chameleon 1

COMPONENTS OF AN ECOSYSTEM: 1.1– (Biotic) Living things: are animals, plants… that live in that place. There are different species living together 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, forest…)

1.3.– Relationships between living things and nonliving 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 important changes in these relations (for example if there are more consumers, or predators…), the ecosystem will change.

Different species in an ecosystem 2

Plague of rabbits in Australia (1.961) 3

COMPONENTS of an ecosystems are: .– Biotic part or living things: (animals, plants…)

2.– TYPES OF ECOSYSTEMS. There are many different types of ecosystems: .– Abiotic part or non-living things: (water, temperature…) .– Relationships between living things and the environment.

Aquatic and terrestrial.

2.1.– AQUATIC ECOSYSTEMS: A.– Freshwater ecosystems: in rivers, lakes…

B.– Marine ecosystems: in the sea or oceans.

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.– ecosystem

.– biotic part

.– abiotic part

.– aquatic .– terrestrial

.– freshwater

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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)...

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

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).

Climate zones on Earth

Terrestrial ecosystems depend on the climate zones.

A.- TROPICAL ZONE:

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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.

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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.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.

Ecosystems in the TROPICAL ZONE: .– Tropical rainforest. .– Savanna. .– Hot desert.

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USEFUL WORDS: .– temperature .– precipitation .– tropical zone .– temperate zone

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.– vecinity to the sea .– polar zone

.– altitude .– tropical rainforest

.– latitude .– savanna

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B.– TEMPERATE ZONES: Ecosystems in the TEMPERATE ZONE: B.1.– Mediterranean ecosystem: .– Mediterranean ecosystem.

It’s cool in winter and hot and very dry during summer. .– Deciduous and coniferous forests.

Trees, bushes and grass are adapted to dry summers.

Near the Mediterranean sea and other places.

11 Deciduous forest

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12 Mediterranean ecosystem

Ecosystems in the POLAR ZONES: .– Tundra. .– Cold deserts.

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.

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14 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: A FOOD CHAIN is formed by: .– Producers or autotrophic organisms: plants, algae... .– Consumers or heterotrophic organisms: herbivores, carnivores &omnivores. .- Decomposers. .– Mediterranean ecosystem .– deciduous forest .– tundra .– producers/autotrophic

.– coniferous forest .- consumers/heterotrophic

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.– cold desert .– decomposers

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A.- Producers (plants, algae, bacteria): they produce their own nutrients from non–living things: water, minerals, sunlight, gases… They are called autotrophic organisms.

B.- Consumers (animals): get nutrients from other living beings, (plants or another animals). They are called heterotrophic organisms.

There are different types: .- Hervibores: they eat plants. .- Carnivores: they eat other animals: 17 .- Omnivores: they eat plants, animals…

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

19 The Chain Food must be balanced, in other case the ecosystem will change. 18 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 develop 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…)

20 Family of lions

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...

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 USEFUL WORDS: .– Family .– gregarious association

.– society

21 Gregarious association: wildebeests

22 Society of bees: Queen & workers

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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 relationship. Species need each other.

Example: Bees get pollen from flowers, and at the same time flowers are pollinated by bees.

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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.

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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.

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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).

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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: animals, plants and natural resources. On the other hand, we interact in a negative way with the environment.

Polluted human landscape

USEFUL WORDS: .– mutualism .– commensalism .– parasitism .– parasite .– host .– predation .– predator .– prey .– exploit .– natural resources

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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 resources, 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.

Air pollution

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.

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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.

Iberian Lynx is in danger of extinction

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Sustainable development is the development that meets needs from present life with needs from future generations, to preserve our world.

4.B.– SOLUTIONS: The solution to these type of problems is the sustainable development.

We must contribute to preserve our environment with different actions:

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.

Wind power in Madridejos 30

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B.2.– Stop the global warming, mainly reducing pollution 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.

Spanish Imperial Eagle is protected by law

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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 countryside) when you visit the mountains…

4.– Others

.– pollution .– global warming .– extinction .– sustainable development .– renewable / non-renewable energies

.– greenhouse effect .– biodiversity

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