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Deer Exclosures to monitor excessive deer damage

An exclosure prevents deer grazing/browsing in a representative area of a habitat and is used to demonstrate, for a period of a few years, the difference between areas with no grazing/browsing (inside enclosure) and adjacent areas, the “control” outside the exclosure.  This gives an indication of the effect that deer are having on the growth of a habitat. Exclosure plots are a simple and cost-effective way of understanding and demonstrating deer impacts on plants, which ultimately also has an effect on the biodiversity of that area.

5 exclosures in all were erected.  The first one was in Football Meadow, an area in Ram meadow adjacent to the football ground, encircling a tree which has ivy growing on it.  This is a regular plant-target by muntjac and browsing causes an absence of leaves all the way up to a ‘browse line’ easily visible in the photo above.  Our resident deer expert, Rob Jackson, explained that muntjac don’t like to be enclosed so they are unlikely to jump into these cages, hence the name exclosure.  Four metal panels each 8 x 4m were erected in a square with wire and cable ties holding them secure.  A small trench was dug all-round the perimeter to put the panels in and then each panel was secured to the ground all the way round with sturdy, heavy duty tent pegs.  Lengths of wood gleaned from the area we were working in, were tied to the top of the panels, to give the cage more stability, strength and sturdiness. 

The second cage was erected on the peninsular further into Ram meadow behind the football ground, near to ditch F1.  One of the panels was bent round in a curve to accommodate a shrub that was near to the ground. 

A horizontal ‘browse line’ is the height up to which deer can reach to eat and can be seen all over woods in the UK. It enables you to see right through a thicket or wood to the other side.  Woods and green spaces should have an understory, which is a thick layer of vegetation carpeting the ground. This understory is completely absent in many parts of Ram meadow where the deer pressure is immense.
The third cage was positioned on the slope facing Ram Meadow in Ram Meadow East.  This area had been vacated by the travellers and there are some interesting plants which have not suffered from disturbance over the years.  This cage contained a bramble bush, to demonstrate the nature of browsing on small shrubs. 

Two more cages were erected in meadow grassland. One in Crankles South meadow, as this area is our most floriferous and one in Elm Meadow (within No Man’s Meadow) where over several years, we have sown or planted plug plants.  Both these areas are scythed in the summer but it will demonstrate how many flowers succumb to deer browsing.