What is Ecological Hierarchy Theory?

When discussing ecological hierarchy theory, it is important to understand arrangements of relationships biological organisms have with one another. Think both in larger groups up to the larger biosphere on down to the individual, microscopic, organism level. Think also about single interactions, as well as large scale interactions, as well as complex and multifaceted interactions.

  • First Level – Individuals – How does one single organism interact with its environment? Examples of Individuals are a cat, a cow, a flea, a dog, a tapeworm, etc. Single individual of a single type of organism. A type of organism is referred to as the species. Note* the term species is always used, there is no specie. Also, scientists give species a two-part binomial scientific name. For example: Homo sapiens = humans, Felis catus = domestic cats, etc.
  • Second Level – Populations – How does a single type group of individuals interact with their environment? This is a group of individuals that all belong to the same species AND which all live in a particular scaled area. For example: The population of humans in a city, state, or continent.
  • Third Level – Communities – How does a “community of life”; all life within a localized community interact? Similar to Populations, communities can be studied in a given area. Importantly, community study involves multiple populations of all different species in a given area and how they interact with each other.
  • Fourth Level – Ecosystems – A community is a part of an ecosystem, but is not all of the ecosystem. This level of hierarchy considers both living and nonliving factors, i.e., a lake, forest, or prairie.
  • Fifth Level – Biosphere – This level represents the larger study of the totality of all things on Earth. Cyclical or trending temperatures and their effects, human impact, deforestation, pollution, etc. are more negative examples. Unfortunately, large positive impacts of humans aren’t apparent, unless per cap is a positive. Humans are flourishing at the expense of the biosphere. – Feel differently? – Feel free to become a member and join the conversation.

Resources

https://education.seattlepi.com/ecological-hierarchy-4489.html

https://www.khanacademy.org/science/high-school-biology/hs-ecology/hs-introduction-to-ecology/a/ecological-levels-from-individuals-to-ecosystems