Ecosystems
Ecosystems explain the way in which living organisms like animals and plants
(biotic) live together with the non-living environment, the soil and climate
(abiotic). There are several different types of ecosystem:
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Aquatic (freshwater)
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Terrestrial (land based)
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Marine (seawater)
Ecosystems are found anywhere where there are living organisms. They vary in
size and can be as small as a puddle or as large as a rainforest. Ecosystems
can even be found in extreme environments, like Antarctica. The world’s largest
ecosystems are called biomes.
How does an ecosystem actually work?
The diagram below shows how ecosystems work. It is like a food chain.
A. The SUN.
This is the source of energy in an ecosystem. Light energy from the sun is
absorbed by green plants through Photosynthesis. The energy is stored in plant
tissue.
B. PLANTS.
As well as getting energy from the sun, plants absorb nutrients like calcium
and nitrogen from the soil, through their roots.
C. ANIMALS.
These eat the plants. Some animals only eat plants, these are called
Herbivores. By eating plants, the energy and nutrients are transferred to the
animals and are stored in their bodies as muscle and fat.
D. ANIMALS.
Carnivores eat other animals. The energy and nutrients are transferred again.
Some animals eat plants and animals, these are called Omnivores.
E. DECOMPOSITION.
When organisms die, the nutrients are returned to the soil. Fungi and bacteria
decompose the dead material, making it ready for re-use. The whole process can
then start again
Scientists study ecosystems for a variety of reasons:
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They can look at the relationship between the biotic and abiotic environment in
a variety of places (land, sea.)
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They can use this information to learn more about natural changes and help to
predict them.
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They can look at how the actions of humans can harm or protect ecosystems.
Antarctica
Human effect on ecosystems is very important and needs to be carefully
considered and here Antarctica is no exception. Antarctica is a very important
place for scientists to study ecosystems, as it is an extreme environment that
is very cold. Where it is very cold, the speed of the ecosystem cycle is much
slower than in hot and wet conditions, like a tropical rainforest. The slow
changing systems of Antarctica have fewer species within them and more obvious
environmental controls like temperature. As changes are slow here, scientists
can carefully investigate them.
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