Acid grassland and biodiversity on Friary Hills

Friary Hills, which is best known for its spectacular views over the freshwater grazing marshes and saltmarshes beyond the village of Blakeney, is the focus of a National Trust conservation project to rejuvenate acid grassland habitat and increase biodiversity on the 4.5 hectares site. 

A nationally important habitat

Since the 1940s, traditionally managed, wildflower rich grasslands have declined nationally by 97%, contributing to the drastic decline of many species including bumblebees, farmland birds and wildflowers.  

In Britain, under 30,000 hectares of lowland acid grassland remain. It is considered a nationally important habitat. 271 Sites of Special Scientific Interest have been notified with acid grassland as a principal reason for the designation.  

Species found in acid grassland

It’s hoped that by improving the acid grassland at Friary Hills it will become home to a diverse array of plant species, with some examples around the country containing as many as 25 plant species per square metre. 

A healthy acid grassland habitat is rich in fine grasses, lichens and mosses, as well as small rosette-forming species such as cat’s ear and mouse ear hawkweed, low-growing herbs such as sheep’s sorrel and bird’s foot trefoil, and tiny annuals such as common stork’s-bill, changing forget-me-not, and parsley piert.  

Many of the invertebrates that occur in acid grassland are specialist species which do not occur in other types of grassland. National Trust rangers hope that improving the health of the acid grassland will make wildflowers like harebells and common stork’s bill, and butterflies such as green hairstreak and small copper, a more common sight on Friary Hills. 

Acid grassland on Friary Hills

National Trust Ranger, Will Ingleton, said:  

“By improving and creating a mosaic of acid grassland and scrub on the north-facing slopes of Friary Hills, it will further support the thousands of migratory birds flying in from the continent that use this area to stop and rest. 

“The acid grassland on Friary Hills has come under increasing pressure, from non-native species that have established themselves and are now competing with native plants. 

“In addition, scrub and tree cover has increased over the last 20 years and is starting to encroach on areas of acid grassland. Meanwhile, a decline in the number of rabbits has removed an important component for maintaining healthy grassland – animal grazing.”

How acid grassland will be restored

The National Trust has stepped up its work to increase the overall amount of acid grassland on Friary Hills, and to enhance its condition, whilst maintaining the balance of a mosaic of habitats on offer for wildlife and people.  

To increase the amount of acid grassland on Friary Hills and improve the overall habitat, the National Trust will be cutting back scrub and removing some non-native trees such as black pine, turkey oak and beech. A number of trees will be retained and work has been timed to avoid bird breeding season. 

Alongside this, National Trust rangers and volunteers will be working to optimise the structure and species composition of the grassland through an annual programme of mowing and cutting. Longer term, the National Trust hopes to introduce sheep or goats onto Friary Hills to assist with this process through natural grazing.

Preserving a mosaic of habitats

Will Ingleton, added:  

“We have made a number of small-scale improvements in recent years. However, this autumn and winter, visitors to Friary Hills will see us cutting back a larger area of gorse and removing the odd non-native tree. As the project progresses, the balance of habitats will shift towards there being more open grassland on the slopes of Friary Hills. Patches of scrub will be retained to maintain a mosaic of habitats, which is important for biodiversity.  

“The habitat changes we are aiming to support will become evident over the coming years, when we look forward to seeing an increase in the grasses, wildflowers, lichens, mosses, and invertebrates associated with a species-rich, thriving acid grassland.”