|Belt transect data for the site is based on between 6
-16 samples depending on the width of the section sampled at the point of the transect
line. The mean number of samples per section was 7. This number was adequate for certain
of the sections (3,4,5 and 9 -Figures ;C,D,E,I above) but not for the other sections.
Random sampling was introduced in 1997 to give better overall cover of the sections and to
incorporate a greater number of samples for each section. The mean number of random
samples for each section was 14, which is a sufficient level of accuracy as determined by
the overall species area curve (Figure J above).
sampling data is a better reflection of the vegetation on the site because the samples
potentially cover the whole area of each section and not just a narrow band across the
middle, as in the belt transect. The distribution of many of the species on the site is
patchy, and the greater the area sampled, the more accurate the data will be. The belt
transect data, while inadequate on its own, in combination with the random samples gives a
good picture of the vegetation on the site and its changes over time.
For the reasons outlined above, where changes are being compared for
the years 1996 - 1998, only belt transect data is used, to allow strict comparisons to be
made. Where the years 1997 and 1998 only, are being compared, an average of belt transect
data and random quadrat data has been calculated to give a mean value which encompasses