Unit 5: The structure of the ecosystems                      1   2   3   4   5   6

1. Ecosystems

An ecosystem is the join of organisms which lives in a particular area, the physical components and conditions of this area and the relationships that these living beings establish among them and with their physical environment.

Ecosystems can be very diverse. They can be aquatic (e.g. a river) and terrestrial (e.g. a field). They can be small and with well-defined limits, like for example, a lake, and they can be large and with undefined limits as an ocean or a forest.

Biomes are large geographical areas with similar climatic conditions that have similar ecosystems too. The ecosphere is formed by all the ecosystems of the Earth.

Ecosystems have two components: biotope and biocenosis.

     - The biotope is the inert part of the ecosystem formed by:

             - the physical environment (rocks, air or water)

             - the abiotic factors. They are the physical and chemical elements

               of an ecosystem which affect living organisms, such as temperature,

               humidity, solar radiation, etc.

- The biocenosis is the living part of the ecosystem. It is the set of living beings

   that form part of the ecosystem: animals, plants, fungi and microorganisms.

   They are known as biotic factors.

        - All the organisms of the same species that live together is a population.

        - The join of populations of an ecosystem is the community or biocenosis.

Animation: Components of the ecosystem (Edumedia)

1.1. Name the appropriate term for each of the following ecosystem

        components:

            a. All the living things in a river

            b. The temperature of the sea water

            c. All the birds of the same species in a pine forest

            d. The sand of a beach

1.2. What is the difference between ecosphere and biosphere?

1.3. Listen and identify which of the two terms of each couple is described.