Faculty of SITE Northern Territory University Flora & Fauna Survey Techniques
what is flora and fauna survey?
why survey?
factors to consider
preparing to sample
flora survey techniques
vegetation descriptions
sampling concepts
fauna survey techniques
analysing data
presenting data

Sampling concepts

It is often impractical to describe the species composition (or floristics) of a site. Hence a sample is collected to obtain a subset of data that is assumed to represent the entire site or population.

Sampling gives estimates of true population values and each independent sample will give a different estimate. Variation among estimates is a result of the following:

  1. The heterogeneity of the population being sampled or arrangement of individuals within it.
    Vegetation is rarely homogeneous. Usually there is a diversity of species - some may be abundant, some rare. Also, the plants may be distributed in a variety of spatial patterns (e.g. clumped) due to random historical events or small-scale landscape features. In addition, there may be considerable variation over time in the distribution and abundance of some species.
  2. Sample design (i.e. number of plots, size, shape and placement of sampling plots).
    Sampling design is essential in determining the efficiency of sampling, the value of the data and which statistical models may be applied during data analysis.
  3. The interaction between these two factors.

Sampling methods and Sampling criteria will provide you with further information.

Tropical Savannas CRC top of page

Tropical Environmental Management Course Homepage
last updated by lrp@cdu.edu.au 6 August, 2004
© Copyright