7.2.3

Assessing Ecosystems

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Assessing Ecosystems

Population sizes are interesting to ecologists. Experimental tools for looking at ecosystems and their populations include:

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Quadrats

  • Quadrats are square frames that can be used to estimate population sizes.
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Transects

  • Transects can be used to investigate the effect of a factor on the distribution of a species.
  • A transect line is a piece of tape that is stretched across the habitat of interest.
  • Quadrats are placed at regular intervals along the transect line.

Organism Abundance

When discussing organism abundance, the following terms may be used:

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Mean

  • The arithmetic mean is the average value of a series of numbers.
  • The mean is calculated by adding up all the values and then dividing by the number of recordings that have been made.
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Mode

  • The mode is the most common value in a series.
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Median

  • The median is the middle value in a numerically ordered series.

Jump to other topics

1Cell Biology

2Organisation

2.1Principles of Organisation

2.2Enzymes

2.3Circulatory System

2.4Non-Communicable Diseases

2.5Plant Tissues, Organs & Systems

3Infection & Response

4Bioenergetics

5Homeostasis & Response

6Inheritance, Variation & Evolution

7Ecology

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