Heather on Exmoor under threat from climate change

Exmoor in flower in the Heddon Valley, with Exmoor beyond

Every August, the hills of Exmoor are usually awash with a haze of purple. But the hot summer of 2018, and thriving numbers of heather beetles, have turned acres of heather from glorious purple to a muddy brown this year.

Heather under stress on Exmoor

Last year’s high temperatures and lack of rain damaged a large area of heather on Exmoor. This year there's an orangey brown colouration to the plants showing they are seriously stressed and unlikely to flower. 

The milder winter also led to an increase in the heather beetle numbers, as it wasn’t cold enough to kill off their larvae. The beetle is a natural element of the heather ecosystem, and damages the outer layers of heather leaves, making the plant more prone to drought stress. 

" We are seeing damage across hundreds of acres of heather and on our neighbouring land"
- Basil Stow, Area Ranger, Holnicote estate on the edge of Exmoor

Knock-on effects  

The lack of blooming heather has serious impacts other wildlife, such as emperor moth caterpillars, which rely on the plant for food. Another unfortunate consequence of the heather suffering is that tougher plants such as moor grasses (Molinia) have chance to take hold. An unexpected side effect of the prolonged warmer weather could be the proliferation of the heather shield bug – a natural predator of the heather beetle. 

" We are seeing first-hand the impacts of climate change on special landscapes within our care."
- Keith Jones, National Trust climate change specialist

What can be done to help the heather?

Heather is a resilient plant and capable of regenerating from the rootstock or from seed - so we'll be watching and waiting to see what happens next year, but are hopeful that it will recover with careful management.

The team at Holnicote, on the edge of Exmoor, are already working on a solution to help with the land drying out. They're planting more trees to help slow the flow of water further up the valley as part of the Riverlands project. They are also restoring wet habitats such as blanket bogs and mire, which hold water in high rainfall and release is slowly in times of drought.