The Woodland Education Centre - Woodland Project Phase 2 Survey Report
|Removal of the Rhododendron and the underlying leaf litter layer has resulted in a 42% increase in species diversity on the project site. This increase in diversity has occurred very rapidly given that clearance was completed less than one month prior to this second survey.
|Ground flora was almost totally absent prior to Rhododendron clearance due to minimal light levels under the Rhododendron canopy. The observed increase in species diversity is due in part to new species rapidly colonizing the cleared woodland floor, now that the light levels have increased sufficiently. It is also due in part to a continuing increase in diversity in the pilot project area (Area 3). Nearly three years of regeneration in this region has resulted in a species diversity more than double that of newly cleared areas.
|Seedlings occurred in surprisingly high densities across most of the
project site, given the short length of time that has elapsed since clearance was
completed. The majority of the seedlings belonged to tree species already present on the
project site, but seedlings of several perennial species such as Foxgloves, Brambles,
Gorse, Ivy and Honeysuckle were also present.
It is likely that germination (from the seed bank present in the soil) was promoted by the raking and removal of the leaf litter layer. Area 4 showed little sign of regeneration in comparison to the other regions, containing few seedlings and virtually no mosses in the ground layer. This is likely to be due to the fact that this area, although cleared first, was the last to be raked. There has therefore been less time for germination and establishment to occur in this area.
The regional differences in Rhododendron cover and physical habitat observed prior to clearance were reflected in regional variations in regeneration across the project site. These included variations in species composition and individual species density. Some, if not all, of these regional variations were attributable to the nature of the original Rhododendron cover.
Rhododendron regenerates very rapidly after clearance, particularly in areas which were previously densely covered. In Area 2 on the project site, 58% of a 20m square was covered in regenerating Rhododendron, less than a month after clearance. It is therefore not enough just to cut down the Rhododendron, the stumps must then be treated with some form of herbicide (in this case, Roundup) in order to prevent regrowth. If this is not done, it would not take long for the Rhododendron to completely dominate the area once more.
Woodland Project Phase 2