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Online ecology one - measuring abundance and random sampling on a footpath

This online ecology practical, from SAPS, uses random sampling to measure the abundance of various different species on an area of grassland.


To give students practice at

  • using random sampling to measure the abundance of various different species on an area of grassland.

To give an opportunity to explore two different measures of abundance

  • density: the number of individual plants per quadrat or per unit area
  • frequency: the proportion of quadrats each species occurs in


1. Lawn survey - area being sampled an aerial view of the piece of grassland being sampled in this exercise. This is 5 m x 5 m. Tapes have been laid along two edges divided into 0.25 m intervals which are the length of one side of the quadrat being used. Follow the link to view this.

10 pairs of random intervals are placed alongside this.

2. Lawn quadrats - 10 quadrats each supplied as a separate image. Each is hot linked to one of the pairs of coordinates given above.

3. ID and recording tables - Tables supplied for recording results (either as density, or as frequency) together with images and names of each of the species likely to be seen. No attempt has been made to separate the grass species but Perennial rye-grass Lolium perenne is the most common species.


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This resource is a Category One Materials