Science & Technology in Action

1st Edition

Protecting Ireland's Biodiversity


This lesson deals with the concept of ecology and the relationships between communities, ecosystems and biosphere. The meaning of habitat is defined. The food web, food chain and pyramid of numbers are also described.
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Lesson excerpt

What is ecology?
This lesson introduces the subject of ecology and the concept of the ecosystem. We then go on to discuss habitats, the food chain, and the pyramid of numbers. We will also learn about Teagasc, the state agency providing environmental advice, research and training.

Ecology is the study of the interactions between living organisms and of their interactions with their abiotic environment.

Living organisms live in communities. A community is a group of species interacting with each other and living in the same area. The community plus the abiotic environment with which it interacts is called an ecosystem.

The boundaries between ecosystems are not sharply defined but gradual. This means that there can be considerable interchange between ecosystems. All the ecosystems of our planet are connected to form a giant ecosystem called the biosphere. The biosphere is the layer of living organisms that covers the earth extending in depth from 3 km below ground to the highest level of the atmosphere.

What is the difference between habitat and ecosystem?
Ecosystem refers to a community whereas habitat is restricted to an individual species. The habitat is the place where the species is living and to which the species has adapted. The species’ distribution may be limited to only a small part of the ecosystem where a unique set of conditions occurs.

Adaptations are ‘solutions’ to environmental ‘problems’ and have arisen gradually as a result of evolution by natural selection. Human induced environmental changes to habitats or ecosystems often lead to the extinction of species because they cannot tolerate the new conditions. Therefore, the conservation of biodiversitydemands the maintenance or re-establishment of habitats and ecosystems.

True or False?

  1. Ecology is the study of the interactions between living organisms. false
  2. A group of interacting species in an area is known as a habitat. false
  3. The community plus its abiotic environment is a habitat. false
  4. The atmosphere is earth's layer of living organisms. true
  5. Sunlight is the major source of energy maintaining the biosphere. true
  6. Plants are producers. true
  7. Producers are micro-organisms that feed on dead organic matter. false
  8. One particular energy flow path is called a food chain. true
  9. The position of a species in a food chain is its niche. false
  10. Herbivores occupy the first trophic level. false
  11. The niche of a species describes its position in a pyramid of numbers. false
  12. A pyramid of numbers tries to show the energy structure of a community. true