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The Earth is covered in living things.
From very large organisms to the tiniest creatures, all living things on Earth have one thing
in common: they cannot survive alone.
To grow and flourish, living things need the support of an ecosystem.
An ecosystem is what we call all the things that interact in a specific area, both living
and non-living.
Ecosystems can be hard to define.
They are interconnected in many ways, and it is not always easy to see where one ecosystem
ends and another begins.
Different ecosystems may look very similar, or very different from one another, but all
ecosystems are made of the same basic parts.
Ecosystems have both living and non-living parts.
The non-living parts of an ecosystem include things like sunlight and temperature, air
and wind, the types and amount of water available, and rocks and soil.
The living parts of an ecosystem are the plants and animals in it.
The non-living parts of an ecosystem combine to create the conditions that will determine
what kinds of living things will be able to survive there.
You won't find a coral reef in the desert or cactus in the ocean, because the conditions
are wrong for them to live and grow.
There are three main types of living things in an ecosystem: producers, consumers, and
decomposers.
Producers produce, or make, their own food.
Usually, they make their food from sunlight through photosynthesis.
Plants are the most obvious example of producers.
Without producers, no animals would be able to survive.
That's because all animals are consumers, and need to consume or eat their food.
Some animals, called herbivores, get their energy from eating plants.
Other animals, called carnivores, get their energy from eating other animals.
There is a third group of animals called omnivores.
Omnivores get their energy by eating both plants and meat.
Humans are an example of omnivores!
Finally, there are the decomposers.
Decomposers are generally bacteria and fungi.
They consume dead plants and animals and break them down into nutrients that are released
into the soil.
These nutrients are used by producers like plants to help them grow, and the cycle begins
all over again.
The living things inside an ecosystem form a community.
Within the community are many different populations.
A population is made of all the members of one specific species.
For instance, all of the plants and animals on the savanna make up the savanna community.
Within the savanna, all of the zebras make up the zebra population, all of the acacia
trees make up the acacia tree population, and all of the lions make up the lion population.
All the parts of an ecosystem must work together to reach a balance that allows each of the
members of the system to thrive.
For example, in a balanced ecosystem predators keep the population of rabbits from growing
too large because when there are too many rabbits they eat too many plants.
If rabbits ate too many plants, the plants would not be able to grow back fast enough,
and other animals that need the plants would not have enough to eat.
Without enough plants the animals that depend on them for food would start to die, and the
soil begins to erode, or wash away, which makes it harder for new plants to grow in
the future.
Ecosystems can become imbalanced when something disrupts their normal workings.
Anything from bad weather to diseases to an erupting volcano can disturb an ecosystem.
Human activity can also damage the balance of of natural ecosystems.
By cutting down trees and clearing forests, building roads and cities, killing some animals,
introducing new ones, or creating pollution, it can become impossible for the plants and
animals in an ecosystem to grow and thrive.
In most cases, ecosystems can recover and regain a healthy balance if given enough time
and an opportunity to rest from whatever disturbed them in the first place.
Since people rely on ecosystems for food and resources, it is important that we try to
protect them.
Fortunately, there are many ways to have a positive impact on your local ecosytem!
By doing anything from picking up trash, planting a tree, conserving water and electricity,
or creating a habitat for wild animals, you can help the ecosystem around you become happier
and healthier.