The challenges of bracken on Pow Hill Heath, Derwent Reservoir

Anne Porter Heart of Durham Blog, News


In 2014 the bracken at Pow Hill Heath, at the height of summer, stood at over  5 feet tall. Its successful invasion has been helped by climate changes and warmer, wetter winters. With the help of Heart of Durham’s band of merry volunteers its success at this site is finally being challenged.

The Heart of Durham Project in conjunction with Northumbrian Water Ltd are tackling the bracken problem and waging an environmental war on its encroachment over this important heathland site. Dense stands of bracken shade out the natural heathland flora of heather and bilberry during the summer months and in the winter the decaying stands have, over the years, formed barren, impenetrable heaps.

In 2016 bracken management commenced with the use of a large specialised roller pulled by a horse. The site was rolled twice. Rolling the bracken bruises the bracken frond, forcing the plant to push out new growth and in doing so it gradually  depletes the energy store in the rhizomes deep underground. Continued bruising reduces the growth and vigour of the bracken, but it is not a quick fix. It may take many years of constant rolling and management to keep the bracken at bay.

 

A small section of heath cleared from bracken litter in May 2017 by Heart of Durham volunteers

 

…. the same area in summer 2014 – overtaken with bracken.

 

Heart of Durham Volunteers clearing off the litter bracken, providing the small heather and bilberry shoots, underneath, access to light. Once they have established they will have a part to play in keeping back the bracken.

 

When the bracken is cleared other invasive species attempt to take hold, like rosebay, willowherb and birch saplings. Here, volunteer, Mike Powell is about to swoop on a small clump of rose bay willow herb.

Looking across the heath site as the rolling of the bracken commences in June 2016

The same spot of heathland before the bracken is rolled for a second time in August 2016. Not quite as high as it was in 2014 but still a force to be reckoned with.

 

In just two months, from the first rolling in June to the second rolling in August the bracken had re-grown by 3 foot

May 2017, at the same spot, volunteers clear the bracken litter to reveal the heath bedstraw and bilberry underneath which would struggle to thrive beneath the bracken litter.  Already, this year’s bracken fronds are beginning to poke through the ground, the area will be rolled once more again just before the fronds unfurl.

With so much bracken debris it is almost impossible for anything to grow underneath, but once cleared at least heathland flora has a chance.

Mission accomplished! Heart of Durham’s volunteers take a bow. Their job at Pow Hill is not complete, not at least for another few years as continued effort is made to pair back the bracken’s encroachment on the heathland habitat. The beauty of the reserve and the difference we are making for wildlife and rare heathland plant communities makes it all the more enjoyable. Why don’t you join us?

Anne Porter

Anne Porter initially joined the Heart of Durham project as a volunteer, helping to carry out adder surveys on an 8-week placement as part of a post-graduate degree in Environmental Management. Anne’s dedication and enthusiasm for her work continues to inspire people of all ages to get involved nature conservation.