Number count method

Number count method

The following process describes how a population number count can be done for many plant species: 

  • Before starting a count, ensure all observers are able to recognise the species in the field and be able to differentiate between individuals of the species or between similar species. If not then further training is required or another technique should be used.
  • Decide whether all size classes (such as seedlings, adults or dead plants) are to be included in the count. This will depend on your objective for the count and resource contraints (such as time available).
  • Then work out the extent of the entire population. This can be done by traversing the site in all directions.
  • If the population is spread over a large area then consider estimating the population size rather than a complete count. Alternatively, do a complete count of only a portion of the study area (by selecting a plot or other sampling unit).
  • Once the population is delineated, conduct a parallel-line search.
  • Mark individuals or groups of plants as you go to avoid double counting. Bright plastic tape, numbered pegs or stickers can be used but remove once finished.
  • Record the number of plants on your field form (the most important attributes to include on a form are the name of the observer, the number of plants counted, the date, the location, the time spent counting and if possible the margin of error between two observers.
  • You may also note any damage to plants caused by activities such as grazing, trampling or picking and other potential threats to the species.

This page last updated on 23 Sep 2012