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Part 9: Collecting Monitoring Data
Quadrats
Quadrats are two-dimensional sample units of any size or shape.
In some cases, a tape may be laid on the ground at each sampling
location to define the quadrat, but more often the quadrat is a
frame created from narrow steel or plastic piping and carried from
one sampling location to the next. Quadrats are used to measure
most vegetation attributes in most vegetation types.
Permanent quadrats are a useful technique when the site
is repeatedly sampled to monitor changes in a vegetation attribute,
such as frequency or density. Quadrat location may be marked by pegs
or by following a grid system. Although labor-intensive to establish,
the permanent sitting of quadrats offers the considerable advantage
of removing some of the error associated with different placement
of the sample unit at each sampling event. Therefore, these techniques
are most suitable for small-scale studies, but are generally impractical
for large-scale inventory or monitoring programs.
A quadrat with one short prong -- made of aluminum
tubing
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