Influence of Spatial Patterns

Spatial patterns exhibited by the species we want to sample have an important influence on the suitability of certain methods to determine density, and the sampling distribution of the collected data. Most theories associated with sampling to determine density assumes the species have a random spatial pattern, but often rangeland vegetation assumes a clumped or patchy pattern.

If counting individual plants, sample unit size can be manipulated to ensure that the collected data follows a normal distribution, regardless of underlying spatial patterns. However, some of the distance methods are sensitive to bias when the species being sampled does not exhibit a random spatial pattern.

References and Further Reading

Bonham, C.D. 1989. Measurements for terrestrial vegetation. John Wiley Sons, New York, NY. pp 127-197.

Greig-Smith, P. 1983. Quantitative plant ecology. Blackwell Scientific Publications, Oxford.3rd ed. pp 26-33.