Skip to content

Pierrepont monitoring, 21st July 2011

by Brian Lavers

Due to other commitments, July’s Monitoring Group day at Pierrepont took place on a Thursday and was spent on the Wey Meadow SSSI (site of special scientific interest) where we carried out the first of our planned annual plant diversity surveys. Rain threatened all day but came to nothing. The occasional burst of brightness brought out the butterflies, prompting Patrick Clear to swing into action with the net and catching the following types of butterfly:

  • small white
  • large white
  • green veined white
  • ringlet
  • speckled wood
  • red admiral
  • comma

plus a couple of others — one blue — which were too quick even for Patrick.

The species diversity study involves examining a number — six in our case — of randomly selected one metre square plots (quadrats) and counting the number of plant species found within each. To add some scientific repeatability each quadrat is subdivided into four quarter square metre frames, each of which is subdivided in turn by a clever arrangement of strings into 25 squares.

By putting the four frames together and laying them over the selected area you therefore end up with 100 ten centimetre squares. If a particular plant species is found in, say, 8 of these squares then 8% of that quadrat contains this species. If this explanation leaves you confused then the photo below will explain all.

Countryside Restoration Trust volunteers with a quadrat frame.

CRT volunteers with the frames for a "quadrat" (see text above for an explanation of how they are used).

This is the simple part. The interest and challenge of course come not in the counting, because most of us can manage that bit, but from identifying the species found. Not counting the grasses (too difficult) we found up to 14 species within some of the quadrats. Bill Young, our leader, will collate our findings in due course and work out a species diversity index for the meadow and also produce a full list of all the species found.

Finally, the chief difficulty encountered during any survey on the Wey Meadow is the number of occasions on which you are distracted from the specific task in hand by the appearance of some other extremely interesting and diverting bird, spider, cricket, butterfly, mammal, etc. This particular exercise was no different: most definitely a species rich environment!

When they are not looking at the ground, Countryside Restoration Trust monitoring volunteers have their noses in a reference book, finding out what it is they have just seen.

When they are not looking at the ground, CRT monitoring volunteers have their noses in a reference book, finding out what it is they have just seen.