Until I started work at Dinnet this summer I had never really given bracken much thought; I was aware that it was a common and invasive fern but that was about it. I was then tasked with the job of keeping it off the paths as it grew to gigantic proportions, clearing areas to make habitat for pearl-bordered fritillary, and keeping the archaeological features free from the green giant. After many days spent hacking, whacking and slashing I built a healthy dislike for the stuff, not to mention the ticks which it harboured. However, this hard work prompted me to investigate bracken a bit further.
Generally people consider it to be a pest. It forms dense impenetrable swaths which mean nothing can grow beneath its canopy and when the fronds die back they create a deep, slow decomposing leaf litter which further inhibits growth of other species. It contains carcinogenic compounds and silica so has no large predators. It also has an extensive under ground rhizome meaning it is difficult to get rid of. Bracken can inhibit woodland regeneration; encroach on habitats of conservation importance such as heaths and species rich grasslands; increase fire risk and cause access problems for both people and grazing livestock.
However, bracken’s not all bad. It can form a protective cover on slopes at risk of erosion. It also provides shelter for many birds, mammals and reptiles. I frequently see blackbirds diving under the huge fronds at Dinnet and hear the rustle of mice and voles as they scurry away on my approach. It also supports over 40 species of invertebrate. Patchy bracken cover near food plants such as violets and bugle is important for pearl-bordered fritillaries, which lay their eggs on the dead litter.
Bracken is a native species. Spores present in peat cores show that it has been present in Scotland for at least 9000 years at both higher and lower abundances than we see today.
Historically people viewed bracken as a valuable resource. It would have been harvested in large amounts for use as thatch, livestock bedding, compost, fuel, dye and in hard time’s food. The Potassium rich ash was also used in soap and fertilizer. It is a combination of these uses being lost and changes in upland land management that appear to have allowed bracken to spread so prolifically in the last century.
Whatever your feelings towards bracken it is hard to deny that it brings a certain beauty to the countryside at this time of year. The woodland around Dinnet looks spectacular at the moment, lit up with the bright greens, yellows and ambers of dying bracken fronds. And no, this sight doesn’t just cheer me up because it means no more bracken cutting this year!