Rare butterfly benefiting from restoration of valuable grasslands
Forestry and Land Scotland (FLS) is teaming up with Butterfly Conservation to restore important and fragile grassland habitat in the Tweed Valley that supports the vulnerable Northern Brown Argus butterfly.
The joint project at Thornielee, halfway between Innerleithen and Galashiels, is seeing staff and volunteers tackle bracken and gorse that is threatening an area of calcareous grassland – a species-rich priority habitat that supports many specialist plants and insects.
One of the species that grows on healthy areas of calcareous grassland is the common rock-rose - the sole foodplant of the Northern Brown Argus caterpillar.
Also helping restore the habitat needed by the threatened butterfly species at Thornielee is a remarkable ecological partnership with one of nature’s industrious workers.
On the southern facing slope there is an abundance of anthills created by the yellow meadow ant and the soil micro conditions created by these ants, allows rock-rose to thrive.
FLS Environment Forester Andy Beverley said:
“At first glance, Thornielee might look like many other forestry sites around the Scottish Borders. However, hiding between the bracken and gorse encroachment is an area of highly valuable grassland.
“Working alongside Butterfly Conservation to control invasive vegetation and taking advantage of the natural ecological relationship between the ants and the Northern Brown Argus, we hope to restore this open habitat for the benefit the butterfly and biodiversity as a whole.
“Work will include a combination of intensive bracken cutting to gradually weaken and reduce its spread along with using robo-flails and conservation cattle grazing where appropriate.”
Apithanny Bourne, Species-rich Grassland Project Officer for Butterfly Conservation said:
“The Scottish Borders is a critical stronghold for this rare species, but many of its last remaining sites are under threat. Through managing bracken and gorse, we hope to restore the grassland at the site. This will increase the diversity of wildflowers, providing valuable nectar resources and larval foodplants for Northern Brown Argus and many other butterfly species.”
An ongoing survey programme will monitor the impact of these habitat management efforts, through annual vegetation surveys, butterfly transects, Northern Brown Argus egg counts and fixed point photography.
Notes to editors
- Forestry and Land Scotland (FLS) manages forests and land owned by Scottish Ministers in a way that supports and enables economically sustainable forestry; conserves and enhances the environment; delivers benefits for people and nature; and supports Scottish Ministers in their stewardship of Scotland's national forests and land.
- Media enquiries to media@forestryandland.gov.scot