CONSERVATION experts will be using horsepower to help control the growth of bracken around historical sites in the Yorkshire Dales.
A special horse-drawn roller has been brought in to crush the plant around the exceptionally well preserved and extensive earthworks of a large group of cultivation terraces dating from pre-Roman times near Threshfield.
And it’s proving to be a success, according to Robert White, Senior Conservation Archaeologist with the Yorkshire Dales National Park Authority (YDNPA).
He said it was the first time the machinery had been used on archaeological sites in the National Park.
“The root systems of bracken are very extensive and can cause very considerable damage to archaeological sites. Basically, the theory is that repeatedly crushing and breaking the stems weakens the plant and eventually kills it.
“On some small sites we have used volunteers to physically bash the bracken but horse drawn rolling is a more environmentally sustainable form of control for larger areas. It has to be done under the right ground conditions and it is important to get the weight of the roller right – too heavy a roller can cause damage to buried archaeological features, too light a roller doesn’t crush the bracken sufficiently.
“The practice was sometimes used in the past although there were other ways of managing bracken – for example, it was cut for animal bedding and it was burned to create potash for soap making. Grazing by cattle also helped keep bracken under control but sheep are too light to have much of an impact on the plant.
“In modern times it has been controlled using a particular herbicide that is now being withdrawn throughout Europe.”