Forestry: Sycamore will be the saviour of English woodlands

FAR from being the scourge of British woodland, sycamore will become its saviour. Sycamore is one of the most beautiful trees on the British landscape, with rich, green canopies billowing out like green clouds against a clear blue sky. It is easy to imagine how illustrators of children’s literature have taken a leaf out of the sycamore book when drawing and painting trees. 

On a more down-to-earth level, I was struck when reading the blog of Paul Wood, who is clearly a fan of the sycamore tree. During a tour of the north of England he noted how important to the upland Pennine landscape the sycamore tree is, where the tree has been part of the scene for generations. He described how sycamore takes on the appearance that oak does further south, where ancient and dignified trees stand sentinel in a field or as a roadside reminder of a long-ago grubbed-up hedgerow.

Why sycamore trees are so much maligned is hard to fathom given these and all the tree’s other positive benefits. Traditionally it was the NGOs and conservation organisations which led the way against sycamore, with the industry and general public taking the lead from them. However, these organisations, including those with the highest profile, appear to have softened their stance against the tree in recent years. 

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Not so the many individuals who still hold grudges against sycamore. Only recently I read a blog with the author bragging about how he had felled three 50-year-old sycamores because their super-efficient regeneration via seed was annoying. Speculation still swirls as to why anyone would want to destroy the Sycamore Gap Tree in Northumberland. It was obviously a famous target for the deranged. My suspicion is that the tree was destroyed purely because it was a sycamore, with the felling showing all the hallmarks of having been carried out by a professional. 

THE CASE AGAINST SYCAMORE

Misguided attempts to remove sycamore saplings by cutting them down simply result in sturdy sycamore coppice in the following years. (Image: FJ)

The case against sycamore was built on an assumption that the tree is not native. 

We are variously told that sycamore was introduced by the Romans or much later during Tudor times (1500s), but this discrepancy alone should ring alarm bells. We can assign firm dates to the introduction of other broadleaf trees like English elm, sweet chestnut, English walnut and Norway maple, so why not sycamore, which did not have to come far from its European base?

And while on the subject, why has sycamore been singled out from the rest of these introduced species, some of which, like sweet chestnut, are now referred to as ‘honorary natives’?
Perhaps sycamore was here all along and is actually a born-again native tree. Indeed, some proponents of this theory have gone as far as renaming sycamore the ‘Celtic maple’. This is not a mainstream view, but the gelatinous nature of Acer pollen is well known for creating uncertainty and raising questions around pollen analysis in palaeontological investigations. 

However, does it really matter if sycamore is not a native tree? Besides its aesthetic qualities, the sycamore tree and its timber offer a full range of practical benefits. After all, qualification for native British status is man-made and arbitrary, being all those trees that became established in the British Isles after the most recent glacial period, which was around 11,000 years ago. But for woodland to qualify for ancient status it only has to have been established on a specific site for 400 years, so why not modernise and make the whole thing more realistic by bringing native tree status and ancient woodland more into line? How about we apply the native label to those trees which were established in the British Isles before the Norman invasion and conquest in 1066? 

However, I will say it again, does it really matter? Many broadleaf species currently classified as alien have done as much if not more for the environment and forestry industry than classic natives like oak, ash and beech. Springing to mind are English elm, sweet chestnut and English walnut, which are native in everything except name. Famed landscape artists like John Constable have painted these exotic trees, poets have waxed lyrical about them and sweet chestnut is the traditional yule log.

WOODLAND TRUST ON SYCAMORE

So what does the Woodland Trust have to say about the sycamore tree? It starts off by saying how sycamore has spread quickly across the UK and colonised many woodlands to the detriment of native trees, but then goes on to give a glowing report on everything from its value to wildlife to the use of timber. 

Here’s what it currently says about sycamore on value to wildlife: “Sycamore trees provide food for a variety of animals, including bees, pollinators, caterpillars, birds and insects. The leaves are eaten by caterpillars of a number of moths, including the sycamore moth, plumed prominent moth and maple prominent moth. Sycamore seeds are eaten by birds, such as greenfinch and goldfinch. Sycamore bark is eaten by insects, including the sycamore lacewing and the sycamore aphid. The flowers provide a good source of pollen and nectar for bees and other insects, and the seeds are eaten by birds and small mammals.” 

I doubt whether you would have read anything like that 20 or even 10 years ago, but reality has caught up. British native and naturalised trees have been going down like flies to exotic pests and diseases, so now is not the time to be picky about what to plant and encourage. We should be grateful for and value all trees, including the sycamore. 

Sycamore is one of the most beautiful trees on the British landscape, with rich green canopies billowing out like green clouds against a clear blue sky. It is easy to imagine how illustrators of children’s books have taken a leaf out of the sycamore book when drawing and painting trees. (Image: FJ)

Many pests and pathogens have impacted the UK’s tree population, but one in particular appears to have concentrated minds. That, of course, is Chalara ash dieback, which has been killing millions of native common ash trees across the British Isles since 2012. It is the nature of the common ash host as much as the disease which appears to have caused major rethinks on the place and value of sycamore on Britain’s landscape. 

Though one (common ash) is inarguably native and the other (sycamore) is presumed to be exotic, these two trees have a lot in common. Both are prolific seed producers with winged fruits (samaras) designed for airborne fruit and seed dispersal, ash with a single-wing samara and sycamore with a twin-winged samara. And this is a major factor in both trees as top-flight pioneers and colonisers of ground, whether in woodland or outside. As such, they are arch competitors, typically found growing side by side in the same sort of places, whether in woodland, on railway or motorway embankments, in parkland, or simply over waste ground.

Indeed, common ash and sycamore are the two trees most likely to be found regenerating by seed in suburban back gardens. 

Sycamore always had the edge over common ash for a variety of reasons – greater seed fertility, no period of seed dormancy and male and female flowers produced and borne on the same tree.

But common ash as the classic native species has always been given precedence, with sycamore regarded as the alien invader and intruder and in many instances afforded ‘weed’ status.

SYCAMORE SAVED BY CHALARA

Chalara ash dieback has changed all that. The disease has taken no prisoners, infecting and killing ash trees of all ages and sizes up and down the country in ancient woodlands in and around England’s capital on deep, moist London clay, carboniferous limestone-rich soils in the West Country – including Cheddar Gorge in the Mendip Hills – and right across northern England on exposed and harsher landscapes and thinner soils. 

Common ash out for the count with sycamore coming in to colonise. (Image: FJ)

The question is: what can replace common ash? There is only one candidate with the broad-ranging ability to exploit and colonise such a wide range of habitats and that is the sycamore tree, with a clearly catholic taste in soils and other environmental situations. And an ability to rapidly exploit by seed regeneration the spatial opportunities left by departing common ash and to colonise the bare ground.  And irrespective of whether it is native (by strict definition) or exotic, sycamore will slot into its new woodland environment with all the wildlife-supporting credentials of a truly native tree, as highlighted by the Woodland Trust.

Sycamore will graduate overnight from ‘scourge’ to ‘saviour’ of our woodlands increasingly denuded of common ash. It is highly ironic that a disease called Chalara has destroyed common ash but saved sycamore.