Hinksey Heights, a steep valley fen on Harcourt Hill in west Oxford, has become overgrown with willow and dense reed over the last 50 years, and the diverse flora and fauna typical of short, species-rich tufa-fed fen has been lost. The Oxfordshire Fens Project is working with the landowner to restore the alkaline short-sward fen here.
One main driver of species loss from fens is lack of management, which allows taller plants, such as Common Reed and scrub, to take over. Practical management work began at Hinksey Heights in 2018, with volunteers working hard to clear trees and scrub and undertake reed-cutting and raking. This helps to keep the tall, rank vegetation under control, which has been outcompeting and shading the smaller fen plant species.
In addition to clearing vegetation, volunteers are also spreading Marsh Lousewort (Pedicularis palustris) seed from the nearby Lye Valley fen. Marsh Lousewort helps to speed up fen restoration as it is a root parasite – its roots join with those of surrounding grasses, rushes and sedges, siphoning off water, sugars and other nutrients. This weakens the surrounding plants, reducing their height and shading ability, thus allowing other small plants to thrive. As an added bonus, Marsh Lousewort is loved by all species of bumblebees! You can read more about this fascinating plant species here.
Some new plants are already appearing in the cleared areas, including Water Figwort and Wavy Bittercress. As management continues we expect more wetland plants and associated insects to return to this fen.
The fen restoration work at Hinksey Heights is supported by TOE with funding from Grundon Waste Management Ltd through the Landfill Communities Fund.