Introduction to Natural Ecosystems

Updated on March 8, 2018

Environmental degradation is a major issue of our time. A basic environmental building block is the ecosystem.

This article is intended to provide a resource for people who want to learn more about what ecosystems are and how they work. When I was working on a project on this same subject, I couldn't find any resources that offered a basic, thorough overview, so I decided to provide one myself!

Along the way, we'll look at:

  • Natural vs. artificial ecosystems
  • The different types of natural ecosystems
  • How an ecosystem functions
  • Human impacts

The Definition of "Ecosystem"

An ecosystem is a combination of two words: "ecological" and "system." Together, they describe the collection of biotic and abiotic (living and non-living) components and processes that comprise a defined subset of the biosphere. (The "biosphere" is the area of Earth that contains life, whether on the planet's surface or in the air.)

Natural vs. Artificial Ecosystems

  • Natural ecosystems may be terrestrial (such as a desert, forest, or meadow) or aquatic (a pond, river, or lake). A natural ecosystem is a biological environment that is found in nature (e.g. a forest) rather than created or altered by man (a farm).
  • Humans have modified some ecosystems for their own benefit. These are artificial ecosystems. They can be terrestrial (crop fields and gardens) or aquatic (aquariums, dams, and manmade ponds).

This article focuses on types of natural ecosystems, how they work, and what we can do to protect them.

Cultivated farms and gardens are types of artificial (human-made) ecosystems.
Cultivated farms and gardens are types of artificial (human-made) ecosystems. | Source

Types of Natural Ecosystems

There are two main types of natural ecosystems, aquatic and terrestrial.

  • In aquatic ecosystems, organisms interact with water. (The prefix "aqua" means water.)
  • In terrestrial ecosystems, organisms interact with land. (The prefix "terra" means land.)

Aquatic ecosystems include oceans, rivers, and lakes.
Aquatic ecosystems include oceans, rivers, and lakes. | Source

Aquatic Ecosystems

Aquatic ecosystems cover 71% of the earth's surface. There are three different varieties, defined by the kind of water in which the system's organisms interact.

  • Freshwater: This type includes lakes, rivers, ponds, streams, and some wetlands, and makes up the smallest percent of the earth's aquatic ecosystems.
  • Transitional communities: These are places where freshwater and saltwater come together, such as estuaries and some wetlands.
  • Marine: More than 70% of the earth is covered by marine (also called saltwater) ecosystems. These include shorelines, coral reefs, and open ocean.

Mountains, forests, deserts, and grasslands are types of terrestrial ecosystems. Text
Mountains, forests, deserts, and grasslands are types of terrestrial ecosystems. Text | Source

Terrestrial Ecosystems

The four terrestrial ecosystems are classified by the type of land or terrestrial area in which organisms interact.

  • Forest: These ecosystems feature dense tree populations, and include boreal and tropical rain forests.
  • Desert: Deserts receive less than 25 cm of rainfall per year.
  • Grassland: These ecosystems include tropical savannas, temperate prairies, and arctic tundra.
  • Mountain: Mountain ecosystems include steep elevation changes between meadows, ravines, and peaks.


How Ecosystems Work

Energy and the Food Chain

Life is based on energy. On Earth, the sun is the primary source of energy. Plants turn sunlight into chemical energy through a process called photosynthesis.

Plants and trees are the energy producers. Herbivores (plant eaters) and carnivores (meat eaters) are energy consumers. They take in the chemical energy from sunlight through the food they eat. With that energy, they carry out all the processes of life.

The food chain illustrates this energy relationship.

When an insect eats a plant, the insect takes in some of the sun's energy. If a bird eats the insect, the energy is transferred again. When a mammal, like a wildcat, eats the bird, then the energy is transferred one more time. This is how energy flows through an ecosystem.

Global Interdependency

All organisms and ecosystems on Earth are linked to one another. They are said to be "interdependent."

The principles of ecological interdependency are:

  • All species are dependent upon one another, either directly or indirectly.
  • When one is removed, whether through extinction or for human use, other species are affected, however indirectly.
  • The impact of one species' extinction can slowly cause the extinction of other species.

An example of these principles is the relationship between sea otters, kelp, and sea urchins. Each species depends on the others. Sea urchins eat kelp and sea otters eat sea urchins. Each of these species are harvested by humans, which can upset the balance among the three. When humans hunt sea otters, their populations decline. When the sea otters are killed or adapt by moving away, then sea urchins increase, potentially devouring entire stands of kelp. If humans harvest too many sea urchins, they can cause a decline in the sea otter populations that rely on those urchins. In response, the sea urchins can rebound in extreme numbers, denuding the kelp forest and discouraging sea otters from returning.


Human Impacts

Without human efforts to conserve natural resources, as well as recycling and reusing those we have already harvested, some of those resources will be gone forever. If we do not take care of our planet's delicate balance of ecosystems, then that will be the end of us and our world.

Ecosystems require balance to thrive. When one element increases or decreases, the ecosystem must adapt to the change. For example, if a meadow or forest ecosystem receives less moisture than is normal, the fruit-bearing plants may not produce as much food for native animals. In turn, those animals will reproduce at a lower rate.

Humans have had a disproportionate impact on the earth's ecosystems. The fertilizers used in farming, for example, often run off into streams and lakes, causing more algae than usual to grow. The increased algae kills off plants and animals in the lake, throwing the lake's ecosystem out of balance.

Human behavior has introduced pollution into the earth's ecosystems through the air, water, and soil. Also, our use of natural resources, especially fossil fuels, is altering the environment in serious and alarming ways.

Are you taking any steps to save the environment?

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    • profile image

      khan 3 months ago

      thanks uuu so much..this would be enough for my assighnment

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      4 months ago

      iam so lost and late if any one happened to stumble opon this comment please be very kind and help me findout how much ecosystems are there and please suscribe to my channel if i get 20 i wil make my first video o and my channel name on youtube is Eshauna M cQuilkin love ypu guys and thanks anyway if you dont but i will really love for you to help me to find my information for skool and to suscribe

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      maria lesiel 15 months ago

      this is a big help for me. it gives me additional knowledge on my studies especially on my exam... thanks a lot, more power and God bless...

    • profile image

      JUBLES 16 months ago


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      LOL 17 months ago

      thanks it works

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      Ayush Sinha 17 months ago

      It's very helpful thanx I got the appropriate answer for my exam

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      thaddaeus 21 months ago

      this is really helpful for my mid report

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      ashi 2 years ago


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      lil savage 2 years ago


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      fish 2 years ago

      this was h elp ful my essay thing said what are benefits of your ecosytem (desert) i put less than 25 cm of rain fall a year . :)

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      sree 2 years ago

      it is helpful for children to get a more knowledge

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      Bharath 2 years ago

      Thankyou for my exam

    • profile image

      Jessy Villa 2 years ago

      Thank you very much ! It helps me to do my project !

    • profile image

      chrishilda sarcol 2 years ago

      hay ang hirap hindi ko maintindihan.........

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      meccka 2 years ago

      protec the mother nature and help the endengerd spiceis

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      aishwarya 2 years ago

      hey pple info reallyyy hlpd me a looot in makein ma prjsct..tnkuba lot

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      mallika 2 years ago

      I like my environment some people destroy the nature like cutting the trees that should be avoided

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      2 years ago

      very nice note related environment. thanks lot.

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      abing sumpi kago 2 years ago

      Thank is really wonderful da way this article describe ecosystem. It help me a lot.....

    • profile image

      bakhtawar 2 years ago

      I like it

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      Ronald sowan 2 years ago

      thank u 2 help me sir

    • profile image

      rasika 3 years ago

      was very helpful osome

    • profile image

      tanishka 3 years ago

      Its osum!

    • profile image

      sham 3 years ago

      supreb yaar u

    • profile image

      kumar 3 years ago

      not easy to understand

    • profile image

      Rjade!!.. 3 years ago

      Gosh!! Science so hard

    • profile image

      nisheet zehbi 3 years ago

      nyc effort. but can b even better and elaborated. thanx anyways :)

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      rose 3 years ago

      i hate science bad

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      subhash kushwaha 3 years ago

      Very very thank u sir

    • profile image

      sneha 3 years ago

      this helped me for my exams thanks........sir

    • profile image

      Divya Kushwaha 4 years ago


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      ELLAJOY 4 years ago


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      Banita sinha 4 years ago

      Thnx for the vital information.... it has helped me in making my bio project...

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      zohaib farman 4 years ago

      plz add ecosystem its component and its types in one topic

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      brealiana5901 4 years ago

      Tnx a lot for the info...

      its very helpful...

      save mother earth!..people

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      JANANISELVARAJU 4 years ago


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      BAHO BOTO 4 years ago

      ANU YUN.......!!1

    • profile image

      abra 4 years ago

      tnx a lot

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      angel roshani 4 years ago

      stop!!! stop !!! stop!!! pollution ........

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      Sadaf 4 years ago

      You May Include the Types Of Artificial Ecosystem With Main Points Clearly.

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      Forthefuture 5 years ago from India

      thanks to all for commenting on my article..thank you.

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      innocent nhimbe 5 years ago

      the natural ecosystem they have no cultivation occurs

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      isagani taruc 5 years ago

      thamk...for the info...VERY helpful...for me!!!!!!!!

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      pota 5 years ago

      d ko maintindihan men

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      vladimere 5 years ago


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      joseph 5 years ago


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      soumya pandey 5 years ago


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      sne khoza 5 years ago

      I need help about,how the animals interect in forest ecosystem

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      lana 5 years ago

      1-forest ecosystem

      2-narine ecosystem

      3-natural ecosystem

      4-tundra eosystem

      5-fresh water ecosytem

      6-marine ecosytem

    • profile image

      priyanka vyas 5 years ago

      It's good but you can include that how an aquarium made up

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      Mellissa 5 years ago

      This was AWESOME!!!!!!

    • profile image

      Sharanya 6 years ago

      Hi ppl this info really helped me a lot in making my biology project. Thank You once again and keep giving people information about environment and ecosystem. Thanks guys!

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      kathryn 6 years ago

      tnx..i realy appreciate this

    • profile image

      kahot ano 6 years ago

      ang hirap hnd ko maintindihan hay.................... naku bkt ganito

    • profile image

      aLekhYa 6 years ago


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      wednesday 6 years ago

      Hi guys this info really helped me a lot in making my bio project. Thank You once again and keep giving people information about environment and ecosystem. Thank You

    • Forthefuture profile image

      Forthefuture 7 years ago from India

      thanks 2uesday and dramatis.....thank you very much...!!!!

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      Kera 7 years ago from USA

      Hi this is a very nice hub. I'm new here too and just thought I'd drop by to say hi. I saw your comment posted in the forums. Hi.

    • 2uesday profile image

      2uesday 7 years ago

      Even though I try care about the environment it feels like a drop in the ocean when I look around at the waste and pollution that is considered acceptable. I hope you enjoy writing here on HubPages and I think you have made a good start with this page.

    • Forthefuture profile image

      Forthefuture 7 years ago from India

      thanks..thank you very much..!!! sir..!! I would like to say you sir.! thanks again.! and about environment there are too many people ( I am also include) they just say to care of environment.! but don't do anything..! huh...

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      amorea13 7 years ago

      Hi Forthefuture - I liked this hub and learned a lot - I am interested in this subject now though I spent a lot of years not bothering about it!Guess I'm like a lot of people!

      I am also interested, however, in how 'big business' and government are NOT (not really) interested in truly doing anything which will interrupt their income-streams. They TALK about it but don't want to really lose their profits. It's down to the 'ordinary' person - as it always has been. Thanks for this hub - great.