Randomly Located Quadrats to Determine Frequency

When the quadrat layout follows the principles of random sampling, frequency is calculated as the proportion of quadrats where the species was found. Each quadrat represents a sample unit, giving the sample data set a binomial distribution. Therefore, binomial procedures should be followed for the statistical analysis of frequency data collected in this manner.

References and Further Reading

Despain, D.W., Ogden, P.R., and E.L. Smith. 1991. Plant frequency sampling for monitoring rangelands. In: G.B. Ruyle. (ed). Some methods for monitoring rangelands and other natural area vegetation. University of Arizona, College of Agriculture, Extension Report 9043. pp. 15-16.

Whysong, G.L., and W.H. Miller. An evaluation of random and systematic plot placement for estimating frequency. Journal of Range Management 40:475-479.