Predictive species-area relations and determination of subsample size for vegetation sampling in the Transvaal Waterberg

Research note: A time and motion study for two vegetation survey techniques1

“…Following Rutherford & Westfall (1986), Westfall et al (1987) and Westfall (1992), 75 circular 0.02 ha (radius of 8 m) stands were marked on a film overlay delineating the stratified units. Both the survey methods were once used at each of the 75 stands, each method being used by an independent worker and the time taken to complete recording for each stand was noted.…”

“…Implicit in using a model which estimates time as a function of the number of species in the area to be sampled, is a fair estimate of the species richness of the study area. Estimates could be obtained during a reconnaissance of the area or by making use of available information on predictive species area relations (Westfall et al 1987).…”