This week we teamed up with the South Wales Fire Service to carry out a controlled burn at Y Gweira Nature Reserve. The reserve is part of the Llantrisant Common & Pastures Site of Special Scientific Interest (SSSI), a fantastic mosaic of marshy grassland, wet heath and raised bogs, which has been grazed by the Freemen of Llantrisant for centuries.
Y Gweira Nature Reserve sits just outside the Common, and for this reason has probably received less grazing over the years than the rest of the SSSI, resulting in a dense thatch of rush and moorgrass developing. These dense and deep tussocks inhibit growth of more delicate plants, such as the various rarities and colourful wildflowers found on the site, and provide a less appealing meal for the cattle which are such an essential part of maintaining the rich grassland diversity.
Since the reserve is criss-crossed with deep ditches, where rarities such as Cornish moneywort and Royal fern flourish, cutting the grass was out of the question, and we began to consider burning as a potential method for opening up the grassland and encouraging grazing.
With special permission from Natural Resources Wales, a small patch of the reserve was chosen to carry out a carefully controlled burn.
The experts were brought in for this job, and after the site had been thoroughly checked for nesting birds and other vulnerable wildlife, the South Wales Fire Service moved in with their equipment.
The Fire Officers were incredibly skilled at controlling their fire, so that section by section the dead and dry tops of the tussocks were burnt off, with a fast and relatively ‘cool’ flame which causes little damage to the lower ground-level vegetation.
On hand were Fire Officers with beaters, blowers, and back-up water hoses, and our Valleys Volunteer Group, nervously supervising what turned out to be an impressive demonstration and surprisingly gentle process.
The practice of controlled burning is a traditional grassland management technique, which if employed carefully can be an effective tool for opening up and reinvigorating grassland. We've put that method to the test at Y Gweira, and we will be monitoring the patch closely over the next few years to see what changes will result from our carefully executed experiment.
As an added benefit, the Fire Service used the opportunity to train their team in a method of prescribed burning, which is an effective tool for controlling and preventing grassland arson incidents. By carrying out a controlled burn early in the year, combustible material such as dry grass and bracken can be removed from an arson hotspot, making it less vulnerable to fire-setters later in the spring when the fire service becomes so overstretched and our wildlife suffers most.
In the event of a wildfire, the method can also be used to create fire breaks and quickly stop its spread. Fighting fire with fire!