1. The Woodland Project is part of an on-going program of restoration
of the Woodland Education Centre. It will clear a significant area of rhododendron from woodland in a north-eastern section of the
Centre. Rhododendron leaf litter will also be cleared from the project site and burned.
2. The aim of the project is to increase biodiversity in the area through the removal
of the rhododendron. Natural regeneration will be encouraged through proactive management,
which will include some replanting of native species. The regeneration of rhododendron on
the site will be prevented.
3. Three surveys will be carried out during the course of the project. This, the first,
will document vegetation present on the site prior to clearance. The second will be
carried out once clearance is complete, and the third, a year later.
4. Vegetation on the site prior to clearance consisted almost exclusively of
rhododendron and silver birch, oak, rowan and holly trees which had grown above the level
of the rhododendron before it completely dominated the area. These trees were generally
tall and poorly developed as a result of the constant competition with the rhododendron.
The woodland floor beneath the rhododendron canopy was essentially bare of vegetation as a
result of low light levels.
5. The vegetation appeared to be superficially homogeneous, but closer inspection
revealed quite marked differences across the project site. Four different regions were
identified. Each of these was sampled separately. A 20m square quadrat was set up in each
region and the vegetation inside each square was sampled. One of these regions was an area
already cleared of rhododendron two years previously in a pilot project. This region had
thus already had two years to regenerate after removal of the rhododendron.
6. A total of 24 species were recorded on the site. Of these, only 12 occurred in the
areas covered by rhododendron. Twenty two species were found in the area cleared during
the pilot project. Nine of these were species which must have colonized the area after
removal of the rhododendron. Two years of regeneration has therefore resulted in a 75%
increase in species diversity.
7. The species colonizing the cleared area were mainly mosses. Other new species found
in this area included brambles, foxgloves, ivy, a sedge and bedstraw. Holly seedlings were
also present in quite high densities. The main factor involved in this increase in species
diversity is likely to be the increase in light levels with the removal of the
rhododendron. (As little as 5% of full daylight penetrates dense rhododendron canopy.
Light conditions under the canopy on a dull day can require the use of a torch for
8. Although several new species were present in the cleared area, plants were very few
and far between and the woodland floor was still very bare of vegetation. This indicates
that complete regeneration is likely to take a long time. Regenerating rhododendron stumps
and new seedlings illustrate the need for continued control of the rhododendron, even
9. The rhododendron showed different growth forms across the project site. In one area
where the soil was very shallow and covered in flints, it grew in an upright tree-like
form. In other areas, the stems tended to grow horizontally, intertwining into a very
dense tangled web. The difference in growth forms is likely to be due to the fact that in
the region with very poor soil, the rhododendron was competing with silver birch trees
which were present in a density twice that anywhere else on the project site.
10. The identification of regional differences in the vegetation cover across the site
prior to clearance, should aid in understanding future observed patterns of regeneration
in the area.