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The Environment, Levels of Ecology, and Ecosystems

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The Environment, the Ecosystem and Ecology

When first attempting to learn about nature, the different organisms that exist within it and the delicate balance between them, one must try to understand the concepts of environment, the ecosystem and ecology. These may all seem like interchangeable and highly confusing terms, but the fact is that while all three are strongly linked together, there are crucial differences between the three that go beyond their basic definitions.

The Environment

shutterstock_540968701You’ve probably heard the term ‘environment’, thrown around quite often. It’s usually used as a catch-all phrase for the nature surrounding us, which, while not necessarily wrong, isn’t quite accurate either. Environment is defined as our surroundings, including both living and non-living components. The environment includes the elements necessary for our survival, like the air that we breathe, the water that we drink and the earth that we use to grow food. The environment not only affects our ability to survive and co-exist on our planet, but is also affected by us.

The Ecosystem

Now that you know what environment refers to, understanding what an ecosystem is will be easy. To put it as simply as possible; ecosystems are smaller environments within the environment.

To elaborate, an ecosystem is the interaction between living and non-living components, also referred to as biotic and abiotic components, within a definite setting. This setting may range from a small tree to an entire forest.

All inhabitants of the ecosystem, which may be hundreds of species living together, affect each other. An ecosystem is considered healthy when each of its components does its part to sustain it. Sometimes, an outside component, referred to as a stranger, can be introduced to an ecosystem. While this may seem initially harmless, it can be catastrophic. The stranger may be an extreme change in weather, such as flooding or drought, or even a major natural disaster, such as a volcanic eruption or a hurricane. Needless to say, this stranger may be completely unwelcome and can lead to the complete destruction of the ecosystem. In some cases, this stranger may be man-made, such as the different pollutants introduced by humans into water sources.

The biotic and abiotic components of the ecosystem can generally be classified as:

  • Primary Producers
  • Primary Consumers
  • Secondary Consumers

Primary producers are the starting point of the energy flow into an ecosystem. They are the plants that use the process of photosynthesis to utilize solar energy to help them grow, with help from other abiotic components such as water sources and soil. Next, primary consumers or plant-eaters (also known as herbivores) maintain the energy flow through the system by eating these plants. Finally, secondary consumers, who are carnivores or meat-eaters, will feed on the primary consumers. You may recognize this sequence as what is commonly referred to as, ‘the food-chain’. At the bottom of this food chain, are the decomposers, which are microscopic bacteria that break-down the waste products produced at every stage of the food chain. Afterwards, these bacteria will then scavenge the useful by-products which can be reused by the primary producers once again, in order to help sustain the ecosystem they exist in.

As previously mentioned, ecosystems can greatly range in scale and type. To make matters simple, they can be divided into three main scales which are:

  • Micro: Which refers to very small-scale ecosystems, such as a small pond or a single tree.
  • Messo: Which refers to a medium-scale ecosystem, such as an entire forest.
  • Biome: Which can refer to either a large-scale ecosystem or several ecosystems existing within similar circumstances and with similar components.

These varying scales can either be found in an aquatic form, such as oceans or rivers, or a terrestrial form, such as rain forests and jungles.


Ecology is the study of ecosystems. It examines the biotic and abiotic components of ecosystems, their numbers, functions, interactions and classifications. Ecologists help to provide us with a better understanding of how all these living and non-living components exist together in harmony to maintain their ecosystem. To help us do this, they’ve created different levels of ecological organization.

  • The individual, the organism or the species:
    A species is a group of individuals, which are living organisms, that are structurally and biologically similar to each other. Members of the same species can reproduce together to further create more individuals belonging to the same species.
  • Population:
    A population is a species that exists within a particular area in a specific period of time.
  • Community:
    A community is determined by geographical location rather than the species. It can include a highly biodiverse group of populations existing together within the same area, such as a rain forest.
  • Ecosystem:
    As explained earlier, an ecosystem involves the interaction between the living components and the non-living components surrounding them such as water and air, also known as abiotic components.
  • Biosphere:
    Biospheres are the parts of the planet containing living organisms, so they are basically the bigger picture including all of the ecosystems on Earth.


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