The National Trust broke conservation rules over a new method of harvesting heather at a Shropshire beauty spot, the BBC has learned.

The charity, which owns Long Mynd, near Church Stretton, has admitted carrying out trials of seed brush-harvesting last year, but mistakenly believed the process was covered by existing permissions from Natural England.

Farmers who hold commoner grazing rights told the BBC they were disgusted by damage they say was caused to the heath-land.

Long Mynd is a protected Site of Special Scientific Interest (SSSI), and governed by strict conservation rules.

“It’s clear the damage here is severe and has been caused by harvesting heather seed. It’s going to take some years to recover,” said Tom Lloyd, secretary of the Longmynd Commoners’ Association.

He represents a group of sheep and beef farmers who exercise their right to graze animals on the slopes of the seven-mile long plateau.

Seed brush harvesting involves taking seeds from a species-rich donor site and spreading them on areas which need their wild flowers restoring.

Typically, a harvester is towed across the site and seed is brushed into a hopper and the seed is then dried.

This is meant to remove heather seed heads only, thus protecting the main part of the plant.

A site near the Shooting Box public car park, visited by the BBC, appears to have significant heather damage caused by heavy machinery, with signs that tractor wheels have become stuck in mud with piles of unearthed heather nearby.

“We’re really disappointed that National Trust - Europe’s largest conservation body - has felt able to severely damage one area in pursuit of regeneration of another,” says Mr Lloyd, a fourth-generation hill farmer.

“We need them to hold true to the collaborative management that Long Mynd has seen for over 25 years.”