Good news and bad news from Wales

Posted by Dave Lamacraft, Plantlife Cymru Lower Plants Officer

Red eyed shingle lichen - thought, until recently
 to be extinct in Wales. Image © Dave Lamacraft. 

The announcement that three more cases of ash dieback have been discovered in Wales is a poignant counterpoint to the discovery last week of a lichen thought to be extinct in Wales.

The importance of the National Trust's Parc Dolmelynllyn estate (near Dolgellau, Gwynedd), for woodland lichens has been known for some time. In fact it is one of the finest areas south of the Scottish Highlands for the lichens of the 'Celtic rainforest'. Wandering through the woods last week I noticed an ash tree with that indefinable ‘look' about it, something that said “I’m worth a closer look”. It stood on the edge of a glade, was well-lit and mottled with a patchwork of colours from the lichens and mosses covering its bark. It was obviously a special tree; the black smears of the black-bordered shingle lichen were a good sign, but what struck me first was a delicate blue-grey leafy lichen. Although not much larger than a 50 pence piece, the distinctive rusty-red fruits caught my eye. A quick look at Frank Dobson's field guide to British lichens confirmed my suspicions - it was Pannaria rubuginosa, the red-eyed shingle lichen.

Not only is this a most attractive lichen, it was a significant find; it had not been recorded in Wales for almost 50 years and was assumed to be extinct. It was also particularly poignant in a week when another three cases of ash dieback have been found in Wales; as with many of our rarest lichens it was growing on an ash tree. Ash dieback has the potential to devastate our ash trees and the wildlife they support, including many lichens. Some 30% of UK lichens occur on ash - 536 species in all. Of these, 84 are threatened with extinction. It now seems ironic that ash provided an alternative host for lichens affected by the catastrophic decline of elm trees during the 1970s.

With ash dieback in our sights again, the next 12 months will be an opportune time to understand more about the disease and its effects. As well as a halt on the importation and planting of infected ash, we should trial different practical measures to find the best actions for reducing the progression and intensity of the disease. The genetic diversity of our native, non-planted wild ash means that some strains may be less susceptible than others, and observations in Europe suggest that mature trees are more resistant to ash dieback. It could be that widespread felling turns out to be the worst thing to do. We also don't really know how the disease behaves. It could be that ash dieback may spread more rapidly in dense canopies resulting from close planting and a lack of management, in which case thinning and opening up of woodland could be important. This would certainly help other woodland wildlife; flowering plants, birds and butterflies are declining as our under-managed woodland becomes ever darker.

The Chalara Control Plan is about to be published. I really hope this doesn’t ignore the needs of our often overlooked species; the many mosses, liverworts, lichens and invertebrates that depend on our ash trees. The plan needs to set out a sensible, considered, approach for dealing with this disease in the long term, and not be a knee-jerk reaction. As far as we know, a single ash tree is the only home to red-eyed shingle lichen in Wales. It’s a stunning lichen, wonderful to look at like so many in the Celtic rainforest, and I had a real thrill in finding it. I’d dearly like others to be able to experience this too. Yes, we do urgently need a plan, and action, to limit the impact of ash dieback as much as possible, but this has to be the right action; an ill-directed chainsaw could bring about the extinction of red-eyed shingle lichen in Wales in a matter of minutes.

Ash to ashes...

Posted by Dr Trevor Dines, botanist and Plantlife Cymru Conservation Manager.

With the confirmation of ash dieback disease (Chalara fraxinea) in Scotland and Wales as well as England, what will the future hold, not just for this familiar native tree, but also for the other plants and wildlife it supports?

The humble ash tree (our fourth most common tree in Britain) turns out to be a rather important part of the landscape.  A handsome species, it flourishes on base rich soils where its open canopy encourages a diverse flora on the woodland floor. It supports a vast array of native wildlife from the animal, plant and fungi kingdoms, is an excellent coppice tree with fast growth rates, and is great for woodfuel, making it an important tree in terms of managing woodland for the benefit of our woodland flora.

Lady orchid. © Andrew Gagg/Plantlife 

Whilst the floor beech woodlands can be bare, ash woods abound with primroses, ferns, anemones and early purple orchids. In some areas, ash woodlands are home to some very special plants indeed. Native wild daffodils and fragrant lily-of-the-valley prefer to grow in ash woodlands, as do the arching stems of Solomon's-seal and rarities such as lady orchid, Suffolk lungwort and the exotic lady’s-slipper orchid. Spiked Star-of-Bethlehem, a bulb that produces a flower spike once harvested as a substitute for asparagus, has already declined following the loss of elm woods and is now largely confined to the shade of ash trees. Similarly, toothwort, a remarkable plant that lives entirely underground on the roots of trees, its presence only belied when the fat pink flower spikes emerge in spring as if by magic, prefers to grow on the roots of elm, hazel and ash and is already declining across Britain.

Not only important for the plants that grow around it, ash is vital to those plants that grow on it.  As well as a wide range of fungi, mosses and liverworts, 255 species of lichen are recorded as finding a home on the trunks, branches and twigs of ash, a figure second only to oak. Of particular importance are the highly threatened group of lichens known as lungworts, which thrive on the base-rich bark of ash trees in western parts of Britain. Groups of these large, leafy lichens often grow closely together on the same tree, forming a spectacular tapestry of colour and texture.

Lobaria pulmonaria, a lungwort lichen.  © Ray Woods

In addition, ash is renowned for the insects that it supports – over 120 species including gall midges, bark beetles, leaf miners and sawflies - and its fruit are a valuable source of food for many birds and mammals, such as bullfinches and wood mice.

Ash dieback was first recorded in Britain in February 2012, when the fungus was found on trees at a nursery in Buckinghamshire. These had come from a nursery in the Netherlands and since then five other outbreaks in England and Scotland have all been found on nursery stock planted within the last five years.

Plantlife welcomes the ban on imported ash but, with the disease now present in the wild, this measure may be too late. The impact of large stands of ash dying will be considerable. In their place, we’ll probably see a sprouting of other trees - sycamore most likely - to replace the ash, with a completely different bark and leaf shading pattern. This in turn will alter the woodland floor flowers as well as the lichens, mosses and liverworts living on the trees.

Plantlife is keen to ensure the continuity of our woodland – both trees and flora - by encouraging a greater emphasis on woodland management and the natural regeneration of native stock rather than being reliant on planting non-native imports.  As part of Plant Link UK, we have submitted a response to the Food and Environment Research Agency (FERA) consultation on how to tackle the problem. But you can play your part too: if you know of any ash trees planted over the last 5-7 years, do keep a close eye on them and please report any dying ash to FERA or the Forestry Commission.

For more on Plantlife’s call for more sustainable woodland management to revitalise our dark and overgrown woodlands, click here (here for Scotland and here for Wales).

• You can follow Dr Trevor Dines on Twitter: @DrTrevorDines