What is an Ecosystem?

Ecosystem is the interconnectedness of organisms including animals, plants, and microbes with each other and their non-living environment. Examples of the non-living aspects of the environment include climate, soil, water, sun, earth, rocks, atmosphere, temperature, and humidity. In an ecosystem, every living organism has an ecological niche. Hence, what makes an ecosystem is the complex and balanced relationship between abiotic and biotic components with each other in any given location.

The definition of an ecosystem also involves the biological and behavioral interactions between living and non-living aspects that constitute the ecological system. Perhaps by considering a small pond next to your area you’ll get to notice there exists numerous sorts of living things such as plants, insects, birds, frogs, worms, bacteria, and fungi that depend on non-living things including water, sunlight, temperature and nutrients. Thus, this intricate interaction between living and non-living things is defined as an ecosystem.

Earth as an ecosystem stands out in the all of the universe. There’s no place that we know about that can support life as we know it, not even our sister planet, Mars, where we might set up housekeeping someday, but at great effort and trouble we have to recreate the things we take for granted here.
~ Sylvia Earle


According to Wikipedia,

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system. These biotic and abiotic components are regarded as linked together through nutrient cycles and energy flows. As ecosystems are defined by the network of interactions among organisms, and between organisms and their environment, they can be of any size but usually encompass specific, limited spaces (although some scientists say that the entire planet is an ecosystem).

Components of an Ecosystem

The elements of ecosystems are primarily grouped into two, which are the abiotic and biotic components. The elements of an ecosystem detail the ecosystem structure, relationship of the organisms, their distribution, and characteristics of their environments. The concept seeks to describe the non-living (abiotic) and living (biotic) features of the environment which are defined in four basic components.

Abiotic Components

The abiotic elements of an ecosystem include all the non-living things in an environment. Examples are elements such as water, temperature, air, soil, rocks, atmosphere, minerals, nutrients, humidity, and so on. Abiotic components may also depend on how much they receive the energy from the sun that will determine temperature variation or how much rain falls in an area that determines water availability.

The physico – chemical aspects such as soil may as well determine whether a water resource is fresh or salty. These are the components that the biotic factors interact with, and are widely categorized under three divisions:

  • Edaphic factors which are associated with the composition and structure of the including its chemical and physical properties such as minerals, soil profile, soil organic matter, soil moisture, and soil types.
  • Inorganic and organic components. The inorganic components include phosphorous, carbon, nitrogen, oxygen, sulfur and so on. Substances such as lipids, proteins, and carbohydrates include the organic components.
  • Climatic aspects which include the physical and climatic elements of the environment such as atmospheric temperature, wind, humidity, and water.

Biotic Components

The biotic elements of an ecosystem include all the living things in an environment. Producers such as green plants are at the bottom produce their own energy without consuming other life forms. Next are consumers. Consumers are living organisms that prey on producers or other living organisms. There are three main types of consumers: herbivores, carnivores and omnivores. Next are Decomposers or saprobes or saprophytes. They are also the living organisms that break down on the dead protoplasm of producers and consumers.

Producers at the bottom

Producers are the autotrophic organisms, mainly green plants and the photosynthetic as well as chemosynthetic bacteria and algae. They are the producing components of the ecosystem because they use the sun’s energy to make their food and store some of the energy in the form of chemical compounds. Producers occupy the base of the food chain and are the most prominent in the ecosystem. They are also the factors that directly interact with the abiotic elements of the ecosystem during the nutrient cycles as they make their food. Because heterotrophic organisms depend on green plants, algae, and photosynthetic bacteria for nourishment, the amount of energy made by the producers determines the availability of energy in the ecosystem.

Consumers in the food chain

Consumers are the heterotrophic organisms in the ecosystem that acquire energy by consuming other living organisms. Consumers are of various categories and are grouped based on what they eat. The categories include herbivores that eat producers (autotrophs), carnivores that eat herbivores and other carnivores, and omnivores that eat both producers and herbivores. Humans are also grouped under consumers. Nutrient and energy is transferred from the organism being eaten to the eater thereby forming complex food chains in the ecosystem. Only 10% of the energy is received by the eater and the energy transferred becomes even less as the trend moves up the food chain.

Decomposers or Saprotrophs

Decomposers are also known as saprotrophs or reducers. They are heterotrophic organisms that break down waste and dead matter. Examples of decomposers include dung beetles, crabs, earthworms, vultures and certain species of bacteria and fungi. These organisms secrete special enzymes on dead or waste matter which digests the materials into minute particles and absorbs the obtained energy for their metabolism. As they do this, they undertake a critical recycling function of returning the nutrients in the dead organisms back into the soils where plants can take them up to manufacture food. In this process, the decomposers also release to the very last all the energy trapped from the sun by the producers. Thus, decomposers complete the cyclical ecosystem processes.

Potential Threat to Ecosystems

Environmental Pollution

Air, land, water, and soil pollution simply destroy the health of crucial ecosystems. Be it as a result of natural or anthropogenic causes, pollution potentially releases noxious substances and destructive chemicals into the environment that damage the health of living things and degrades the nature of non-living things.

In an aquatic system, for instance, water pollution can disturb the ecological balance by accelerating plant and nutrient growth thereby causing the death of fish because of suffocation resulting from dissolved oxygen depletion. The various implication of pollution is the interference with natural cycles in the ecosystem such as the oxygen cycle, the nitrogen cycle, the water cycle and the food chain, which results in adverse ecosystem damage.

Over-exploitation of Natural Resources

The exploitation of the natural resources to the point of diminishing returns has significantly destroys the ecosystem. Activities such as over hunting, over fishing, over mining, and excessive logging have led to a reduction in community structures, population distributions, and species breeding. For instance, excessive fishing has led to population collapse of more than a third of all fish species and some are currently endangered.

Invasive Species

Foreign species that find way into an ecosystem, either by human or natural initiation can wreck serious havoc on the native members of the ecosystem. Whenever this happens, the native species can be wiped out completely or may find it tough to survive.

Invasive species often compete for food with the native species and can also alter the habitat. This gradually destroys ecosystems and leads to the extinction of species. According to WWF (World Wide Fund for Nature), the introduction of alien Nile Tilapia into Lake Victoria in the 1970s led to the extinction of more than half of the native cichlid fish family.


Eutrophication is the excessive concentration of chemical nutrients in water bodies to an extent that it encourages the dense growth of plant life and algae blooms. Based on the degree of eutrophication, the effects are depletion of oxygen, extensive deterioration of water quality, poisoning of seafood and degradation of recreational opportunities. As a result, it affects the survival of fish and other aquatic life forms. The presence of toxic algal blooms in water bodies has endangered aquatic life and availability of quality water thus posing a threat to ecosystems.

Climate Change and Global Warming

Climate change and global warming are leading threats to the ecosystems. Changes in climates and global temperatures directly impact the abiotic factors essential for sustaining the biotic elements. The present rate of rising global temperatures is destroying and altering the coral reefs, mountain regions, water cycles, which are vital ecosystems resources. For instance, different species requires particular abiotic factors to thrive. If global warming and climate change continue, 10% of the entire world species might go extinct by 2050.

Photo by: kimhiz