Our Environment · Lesson 1 of 8
Eco-system — What Are Its Components?
“An ecosystem is basically nature’s group project, and everyone—including the soil—has a role.”
• Explain how living organisms and physical surroundings together form an ecosystem. • Distinguish biotic components from abiotic components using examples. • Compare natural ecosystems with human-made ecosystems. • Analyse an aquarium as a human-made ecosystem. • Explain why interactions among living and non-living components are necessary for a self-sustaining system.
A garden may look like a collection of separate things: trees, insects, birds, soil, sunlight, wind and water. In reality, these parts are linked. The plants depend on soil, minerals, water, temperature and light. Animals depend on plants or other animals. Microorganisms act on dead matter. When these living and non-living parts interact within an area, they form a working ecological system rather than a mere collection of objects.
Environment In The Context Of Living Organisms
For a living organism, the environment includes everything around it that can influence its survival, growth, reproduction or activity. Some influences are living, such as other plants, animals and microorganisms. Others are non-living, such as rainfall, temperature, wind, soil and minerals. An organism continuously responds to both kinds of influence.
An Ecosystem is formed by all the interacting organisms in an area together with the non-living constituents of their environment.
The word interacting is essential. A patch of soil, a group of organisms and some water placed side by side do not become meaningful ecological components simply because they occupy the same place. The ecosystem idea focuses on relationships: organisms obtain resources from their surroundings, affect other organisms, alter their immediate surroundings and depend on cycles of matter and flows of energy.
Biotic Components
Biotic Components are the living parts of an ecosystem, including plants, animals, microorganisms and human beings.
Biotic components can influence one another directly through feeding, competition and cooperation, or indirectly by changing the surroundings. For example, plants provide food and shelter, animals may disperse seeds, and microorganisms can break down dead material.
Abiotic Components
Abiotic Components are the non-living physical and chemical factors of an ecosystem, such as temperature, rainfall, wind, soil and minerals.
Abiotic factors do not simply form a background. They help determine which organisms can live in a place and how well they can grow. Rainfall changes water availability, temperature affects biological processes, soil provides anchorage and minerals, and wind can influence evaporation or seed movement.
Natural And Human-made Ecosystems
Forests, ponds and lakes are natural ecosystems. Their communities have developed within naturally occurring surroundings and contain many interacting organisms. Gardens and crop fields are human-made ecosystems because people select or maintain many of their components. An aquarium is another clear example of a human-made ecosystem.
| Type | Examples | Important Feature |
|---|---|---|
| Natural ecosystem | Forest, pond, lake | Many interactions occur without constant direct human control. |
| Human-made ecosystem | Garden, crop field, aquarium | People choose, arrange or maintain important components. |
Aquarium As An Ecosystem
Designing an aquarium makes the idea of an ecosystem concrete. Fish need enough space for movement, water, dissolved oxygen and food. An aerator can help supply oxygen, and food may be added from outside. If aquatic plants and suitable organisms are also included, some ecological relationships begin to operate within the aquarium.
Designing A More Self-sustaining Aquarium
Aquatic plants can use light energy to make food and can contribute oxygen to the water during photosynthesis. Animals use food and oxygen and produce wastes. Microorganisms can act on dead matter and waste. The more complete these relationships become, the less the aquarium behaves like a container that depends entirely on external support.
Even so, a small aquarium usually needs cleaning and care. Its limited volume means that waste can accumulate quickly and the number of organisms is small. A pond or lake is generally larger and contains more diverse producers, consumers and decomposers, so natural recycling and balancing processes can operate more effectively.
Problem
A pond contains algae, fish, bacteria, water, dissolved minerals and sunlight. Classify each component.
- 1.Algae, fish and bacteria are living organisms, so they are biotic.
- 2.Water, dissolved minerals and sunlight are non-living factors, so they are abiotic.
- 3.The pond becomes an ecosystem because these components interact rather than merely coexist.
Problem
Classify a crop field, forest and aquarium.
- 1.A forest is a natural ecosystem.
- 2.A crop field is maintained by people and is human-made.
- 3.An aquarium is constructed and maintained by people, so it is human-made.
Problem
Explain why a small aquarium may need cleaning while a pond does not require the same regular manual cleaning.
- 1.A small aquarium has limited space and fewer interacting organisms.
- 2.Waste can build up rapidly.
- 3.Natural recycling through producers, consumers and decomposers may be incomplete.
- 4.A pond is larger and usually contains a more complex community that supports more complete recycling.
An ecosystem is not just a place and it is not only a list of organisms. It is the interacting system formed by organisms and the non-living environment.
Quiz
Which statement best describes an ecosystem?
Which of the following is an abiotic component?
Why is a crop field described as a human-made ecosystem?
Which change would make an aquarium more self-sustaining?
Why may a pond require less direct cleaning than a small aquarium?
Practice Problems
- List four biotic and four abiotic components that could be present in a garden ecosystem, and explain one interaction between the two groups.
- Explain why sunlight should be treated as an abiotic factor even though producers depend on it for making food.
- Compare a forest and a garden as ecosystems. State one similarity and one difference.
- Design a simple aquarium ecosystem by listing the minimum needs of fish and two additional living components that could help ecological balance. Explain the role of each.
- A student says, 'A pond is an ecosystem because it contains fish.' Correct this statement by giving a complete explanation of what makes the pond an ecosystem.
Key Takeaways
• An ecosystem includes both interacting organisms and non-living environmental factors. • Biotic components include plants, animals, microorganisms and humans, while abiotic components include temperature, rainfall, wind, soil and minerals. • Forests, ponds and lakes are natural ecosystems, while gardens, crop fields and aquariums are human-made ecosystems. • An aquarium requires space, water, oxygen and food, and ecological interactions can make it more self-sustaining. • Larger natural ecosystems can maintain recycling relationships more effectively than a simple small aquarium.
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Next · Lesson 2
Producers, Consumers And Decomposers