As you may have noticed the heather on our moors is looking particularly impressive at the moment. Ling heather, or Calluna vulgaris, is at it’s best in late August – September. This type of heather is the latest to flower of our common, native heathers and tends to favour drier, acidic conditions and is often found growing on peat mounds in bogs. Other types of heather include Bell heather, Erica cinerea and Cross-leaved Heath, Erica tetralix. Bell heather also favours the drier regions of our moors and is found growing in and around rocks where, in contrast to the other two, Cross-leaved Heath is more suited to the wetter regions and can be found growing amongst Bog asphodel, Narthecium ossifragum.
How can you tell them apart?
You can usually assume that heather found growing in the wetter regions is likely to be Cross-leaved Heath but the the flowers are quite similar to Bell heather. The difference between the two is the leaves of Cross-leaved heath are in whorls (clusters) of four where they come in whorls of three for Bell heather. The flowers of Cross-leaved heath also tend to be a paler pink and the stems a more greyish-green. The flowers of Ling heather, in comparison, are much smaller, as are the leaves, which are scale like and arranged in opposite, crossing pairs.
The meaning of the latin word ‘Calluna’
Calluna was derived from the Greek word ‘kalluno’ which essentially means ‘to sweep’ which, when you consider how heather creates a purple carpet across our moorland, at this time of year, is quite apt.
Heather for other wildlife
The heathers, when flowering, are a good source of pollen for insects such as bees and butterflies – the former producing excellent honey as a result! There are species of butterfly that use heather as their main food plant in some locations. The Silver-Studded Blue butterfly in some heathland colonies for example, although they are generally restricted to lowland heaths. Red Grouse are closely associated with heather moorlands, particularly where Ling heather is dominant. They feed on the young, more succulent shoots, which is why gamekeepers from shooting estates tend to manage it by burning off the older, more woody stands. The burning has to be carefully managed in order to protect blanket bog habitats which can get damaged in the process.
The future of our heather moorlands
The management of our heather moorlands can be a source of ‘conflicts of interest’ – grouse shooting is a good source of income for local communities, but some of the management techniques are not always in the best interests of other wildlife. More recently organisations have started to realise the importance of these habitats for other reasons. Large-scale restoration programmes have been set up to try and bring them back to a more favourable condition since, in some areas, our industrial past has left conditions so acidic that they cannot support plant life and large areas of bare peat are exposed. In addition the practice of burning has damaged blanket bogs and historic overgrazing by sheep has taken it’s toll. This goes beyond managing the moors for heather alone. Recent research has shown peat as a valuable store of carbon and, with the impact of Global Warming, there is a considerable amount of investment in trying to preserve the whole moorland ecosystem.
What does this mean for our heather?
We may be seeing more heather that favours the damper conditions as efforts are channelled into ‘re-wetting’ the moors since dry and eroding peat soils release more carbon dioxide into the atmosphere. In particular Cross-leaved Heath may become more abundant and the Calluna variants slightly less so.