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SCIENCE 5.
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.-Relationsetween 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 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 important changes in these relations (for example if there are more consumers, or predators…), the ecosystem will change.
C.E.I.P. SANTA ANA (Madridejos)
Different species in an ecosystem.
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Plague of rabbits in Australia (1.961)
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
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.
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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 the 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). Terrestrial ecosystems depend on the climate zones.
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Climate zones on Earth
A.- TROPICAL ZONE: A.1.– Tropical rainforest is near the Equator. It is very hot with lots of precipitations. It is a thick forest with a great variety of plants and animals.
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A.2.- Savanna has got two seasons (a dry season and a wet one). There are lots of grass and bushes. There are a great variety of wild mammals. It is near the tropics.
A.3.- Hot desert with very high temperature during the day, and very low temperature during night. It is very dry, so there is scarce vegetation adapted to live with only a bit of water. Only a few animals can live there. Ecosystems in the TROPICAL ZONE: .– Tropical rainforest. .– Savanna. .– Hot desert. 4
USEFUL WORDS: .– temperature .– precipitation .– tropical zone .– temperate zone
.– vecinity to the sea .– altitude .– latitude .– polar zone .– tropical rainforest .– savanna
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B.– TEMPERATE ZONES:
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Mediterranean ecosystem
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Deciduous forest
B.1.– Mediterranean ecosystem: It is 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.
B.2.– Deciduous and coniferous forests: Deciduous trees lose their leaves in Autumn. Coniferous trees do not lose their leaves in Autumn. They are near oceans, with cold winters and mild summers, and a high level of precipitation.
Ecosystems in the TEMPERATE ZONE: .– Mediterranean ecosystem. .– Deciduous and coniferous forests.
Ecosystems in the POLAR ZONES: .– Tundra. .– Cold deserts.
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. These ecosystems are near the poles.
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Tundra
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. .– Mediterranean ecosystem .– deciduous forest .– tundra .– producers/autotrophic
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Cold desert in the North Pole
A FOOD CHAIN is formed by: .– Producers or autotrophic organisms: plants, algae... .– Consumers or heterotrophic organisms: .– Herbivores. .– Carnivores. .– Omnivores. .- Decomposers. 5
.– coniferous forest .- consumers/heterotrophic
.– cold desert .– decomposers
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FOOD CHAIN
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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 other 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.
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:
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Family of lions
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, eagles…) Gregarious association: wildebeests
b.– Gregarious associations: are groups of living beings that live together, although they are not related each other. (Examples: flocks of birds, flocks of zebras…) 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
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Society of bees: Queen & workers
C.– Societies: are groups of living beings in which there is a level of organization with their work distributed. They are specialized in different roles. (Ex. bees, ants…) There is a Queen, soldiers, 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 for one of the species.
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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 the other species (prey). Example: A falcon (predator) kills and eats a pigeon (prey). Polluted human landscape
4.- HUMAN ACTIVITIES AND ECOSYSTEMS: USEFUL WORDS: .– mutualism .– commensalism .– parasitism .– parasite .– host .– predation .– predator .– prey .– exploit .– natural resources
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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 usually interact in a negative way with the environment.
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4.A.– PROBLEMS: Human beings adapt to different environments, and we change them. Nowadays, we are thousands of millions of people, so we need a lot of natural resources. So there is an overexploitation of these resources, and as a result, there are many different problems:
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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.2.– Global warming and greenhouse effect are changing our climates on Earth, so ecosystems are changing too fast, and these problems are affecting to plants, animals and even human beings.
Air pollution
A.3.– Extinction of species (animals and plants), produced by the change in ecosystems, by deforestation, fires, agriculture, road constructions… Lots of different species are in danger of extinction, and every day many of them are disappering from our planet.
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4.B.– SOLUTIONS: The solution to these types of problems is the sustainable development. We must contribute to preserve our environment with different actions:
Iberian Lynx is in danger of extinction
Sustainable development is the development that meets needs from present life with needs from future 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 do not pollute and we can use them for ever. B.2.– Stop the global warming, mainly reducing pollution and some gases that affect to the quality of air (like CO2). B.3.- Preservation of biodiversity, in order to maintain original ecosystems where animals and plants can live and reproduce. Create more natural parks, and avoid overexploitation, and deforestation. 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 .– greenhouse effect .– biodiversity .– sustainable development .– renewable / non-renewable energies
Wind power in Madridejos
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Spanish Imperial Eagle is protected by law