We are the champions

Do you have a prize tree in your midst? If so, celebrate your good fortune, lavish the attention on it that a champion deserves while putting in place a legacy plan, reports Greg Rhodes.

David Alderman must be the Mr Chips of trees. As honorary director of The Tree Register of the British Isles (TROBI) he has the skinny on 259,000 specimens currently on the books - native, foreign, evergreen, deciduous, tall and thin, fat and squat.

These trees are special, however. No fewer than 76,000 are dubbed champions - locally, regionally and nationally, whether largest girth, unmatched height or widest canopy - the remainder confirming their status.

David and his nationwide network of volunteers conduct a rolling programme of measurements, using hand-held lasers, to verify new entrants to the register and reverify current listings.

"The register reflects the pioneering work of leading dendrologist Alan Mitchell's 'A Field Guide to the Trees of Britain and Northern Europe', which Collins published in 1974," explains David, a graduate in forestry. "Working for The Forestry Commission, Mitchell recorded finest specimens for the purposes of seed collection."

Mitchell had amassed enough data to publish what was the first book of champion trees, mostly growing in the south of England. "He retired in the 1980s, having assembled 70,000 individual records," David continues.

Working alongside Mitchell, assistant dendrologist Vicky Schilling took steps to protect the body of work after Mitchell retired, setting up a board of trustees and a bursary that helps fund the volunteers in their tree-measuring activity.

The Register collection constantly evolves. When one champion dies or suffers damage that affects its status, a contender is waiting to replace it, says David. "We're still unsure how many on the register blew down during Storm Arwen, but it had quite an impact, we believe."

"Checks by our volunteers will confirm those we lost, while National Trust sites that run champion tree trails can provide fast feedback. The public also updates us. We should know by the end of this year."

It's no surprise to learn that the Great Storm of 1987 brought seismic change to the register. "Tallest champions were hit worst," says David, "semi and fully mature specimens mostly. Japanese maple and cherry suffered the biggest losses - often flattened by other trees."

Isolated good news did emerge from the devastation however, David recalls. "Kew managed to winch a couple of its champions back upright to live another day. The whole process of recovery from the storm aftermath changed arboriculture forever."

Landowners and managers have no legal requirement to maintain champion trees over and above other specimens but, adds David, "our role is to raise awareness among those who have champions in the hope that they look after them more sympathetically".

It's worth noting that this mission must surely apply to the nation's veteran trees too. Examples such as the horseshoe oak on Thorndon Park Golf course spring to mind - a gnarled, almost sinister-looking specimen with a hollowed-out trunk large enough to stand within.

It was discovered by the greens team almost strangled by suffocating undergrowth, now cleared away to reveal the tree in its full grandeur.

The parameters for judging a champion are not complex, David notes - "tallest or fattest girth for that species, though if rare, we register a specimen for each feature."

Towering trees such as the evergreen sequoias (most famously the Californian redwoods) are familiar sights in landscaped, older, larger spaces (Victorian pleasure gardens) and estates, However, the tallest examples are found in plantations in Wales and Scotland that have been left undisturbed and unthinned in deep, sheltered ravines where their constant search for light fosters exceptional growth.

"The Douglas Fir predominates," David reveals. "There are more of those specimens reaching over 60m in height than any other species on the register. You'll find them mostly on Forestry Commission land, where they were planted up in the 1920s and '30s."

"They became uneconomical to fell because of their location. The Commission switched to amenity management after WW11 under a plan to make us independent in timber supply. The idea was for faster rotation - 30 to 60 years rather than 100 to 150."

Location is a key driver for attaining record heights, he adds. "The wet conditions in the west of Scotland stimulate more rapid growth, compared to say the drier, exposed climate of East Anglia, where the same species may reach only half or a third the size."

Recording trees can be traced back over 200 years, "particularly oak, yew and chestnut," David says. "Some sweet chestnuts are at least 350 years old - plenty were planted in the 1700s, while some even date back to Henry VIII and Elizabeth I."

Today's monitoring meanwhile also focuses on how climate change is affecting growth rate for different species and the impact different soils have on that.

Counter-intuitively perhaps, younger trees may be at greater risk than older counterparts, David points out. "Many are suffering because of lower groundwater levels as their roots are not as deep or as established as those of older trees."

"A 400-year old oak could be healthier than ones planted recently. It may have been part of ancient woodland or forest for example."

The message is clear then. Planting saplings and young specimens is only the first step in a programme of care that will help ensure your new additions will survive and thrive.

Awareness key

The Tree Register's tally of champions may sound sizeable but given the UK's tree count, despite our lowly ranking in the international leaf coverage league, prize specimens seldom may be spotted. Even in urban or high footfall areas, they may be hidden in plain sight.

Awareness of them is of pressing importance, TROBI acknowledges. "Most champions were planted on estates or self-seeded and left to grow undisturbed," says David. "Tree management has changed a lot over recent years and we have the technology and know-how to make the most of a valuable natural asset that captures carbon and oxygenates the air. Landowners need more financial help and good advice to ensure that asset stays healthy to benefit us all."

Trees generate heightened local interest and passions flare when ones cherished by the community are felled to make way for new developments, as a recent case in Cornwall demonstrated all too starkly amid a media outcry.

"The Register doesn't campaign as such," says David, "but provides information for local groups." Awareness of champion trees as exemplars of what many fear is an endangered branch of Earth life remains pressing.

"When speaking to a local councillor recently, I mentioned the idea of setting up a champion tree trail (CTT). 'What are champion trees?' came the reply."

And that was the same response from an experienced groundskeeper.

The data TROBI collects from gardens, sports and amenity sites and tree collections such as arboreta can give local councils valuable insight into how they can plan and execute tree planting and management programmes, including the issue of street tree sustainability, David believes.

"Our volunteer force of 50 avid tree lovers can only do so much," he says. "It's something people mostly pick up on when they retire and they can work at their own pace, without any pressure from us. Some are incredibly active and super keen, but we could do with more."

More volunteers mean more outlay on the specialist equipment they carry with them to measure current and candidate champions. Laser hypsometers are the tools of choice here and abroad and have supplanted traditional measuring methods.

"Everyone across Europe is using the same equipment to ensure consistency in recording vertical height but it requires traIning to get accurate results," David stresses.

The sheer variety of the register lends a fascinating perspective to the world of trees. "From the incredibly big and tall to the modest and small," David divulges.

"Opening of trade routes from China marked an influx of species new to the UK, while original examples of the dawn redwood, introduced in the late 1940s, have reached well over 100 feet in height."

Which begs the question; What is a native species? "Those that were growing here after the last ice age, 10,000 years ago. We have 33," David states.

Whatever their height, girth or age, whether dowdy or exotic, champions need to be more widely recognised so that we understand more fully trees' capacity to realise their growth potential and the conditions that allow them to achieve it.

One thing's for certain, concludes David, "more champion trees are out there to be discovered." So keep your eyes peeled.

Tomorrow's champions

Keeping tabs on the current register of champion trees is important, as is raising awareness, but is a system in place to give tomorrow's likely contenders a fighting chance to qualify as prize specimens?

Tree ambassadors can help generate a sustainable method of keeping the environmental and societal benefits of green cover up front in the public perception.

"Former head of Kew arboretum Tony Kirkham was one such tree champion," believes Dr Jon Banks, head of research at Bartlett Tree Experts, which specialises in tree monitoring, management and disease control.

"He possessed vast knowledge and was adept at pushing forward awareness of the huge benefit trees offer and the importance of species diversity."

Targeting key messages correctly will help redress the balance of what Jon says is a vicious circle that, if left unchecked, may have dire consequences.

"Nurseries still stock the same species by and large," Jon says, "because they are the ones landscapers specify for their projects."

"The sector's in a Catch 22, chicken and egg dilemma. The temptation is to buy the tree types we are familiar with and that risks driving out less well-known species."

Looking at landscape solutions more in the round and over the longer term can foster diversity and help prevent a potentially dangerous spiral, he adds.

"Adopting the 30:20:10% rule for planting is critical to encourage more widespread take-up of a greater variety of species."

In contrast to larger settings such as golf courses, urban environments are usually more constrained, where heat islands and higher pollution levels (carbon dioxide for example) are more common.

Converging species diversity may well aggravate these factors, Jon argues. "Planting a broader range of cultivars, including drought tolerant ones, will help increase biosecurity."

The capital is renowned for its population of London plane trees, which can reach enormous proportions. Younger examples may well be champions in the making, so protecting them and their environment is critical.

"The London Tree Officers Association, whom we work with, runs a network of good field officers who have the protective interests of such species at heart," says Jon. "The International Society of Arboriculture (ISA) focuses on environmental factors such as carbon storage and pollution absorption."

Creating a powerful legacy of tree management to safeguard future champions depends on implementing systems that put monetary values on both individual specimens and woodland, Jon continues.

"They are already in use. The Helliwell and i-Tree Design models aim to put a price on the amenity and environmental value trees provide."

The Helliwell system has been used extensively in court cases, insurance claims and public inquiries to place visual amenity values on individual trees and woodland, Jon explains.

As such, the parameters it measures also apply in any sport, leisure and amenity landscape. Factors the system takes into account are each allocated scores to give an accumulated total - tree size, life expectancy and suitability of setting all add towards an overall comparative measure.

"Using the system can give you more clout in a court of law," says Jon, adding that placing a price on the worth of a tree especially helps retain older trees."

Current Helliwell point values, as of 1st January this year are £42.97 for individuals and £171.87 for woodland, their website notes.

The online i-Tree Design system is a web-based tool that allows us to estimate the benefits individual trees provide - carbon dioxide absorption, air pollution reduction and energy saving among other factors.

The method gauges tree benefits for the current year and for up to 99 years and can include age and can model estimates for multiple trees and buildings.

"Without applying such systems, we can only offer intangibles and non-economic arguments," Jon states, "when developers are looking at numbers on a spreadsheet."

"Tree preservation orders offer the only protective measure currently, while SSSIs are applied independently of individual specimens. Enforcement for any infringements can be difficult as well."

Succession planning

Protecting the current crop of tree champions is a worthy sentiment but with age and an increasingly stressful environment, ancient trees are in need of increasing care. Up-and-coming generations of ancient trees also need to be identified, evaluated and cared for.

"On the ground, inspections can be hugely helpful to a golf club or sportsground as they can point to what might need maintenance or chopping down," Jon advises. "Presence of a champion does not necessarily indicate that the environment is ideal for it. If a tree does need to be removed, planting young replacements successfully depends on a proper programme of aftercare."

The news could be better on that front. "Research studies reveal that only 30% of plantings usually survive. That rate rises in forests to more than 50%."

Watch out, a champion's about

Nationally important Grade 1 listed Leonardslee Lakes & Gardens, near Horsham, West Sussex, is in the throes of creating a champion tree trail (CTT) reports head gardener Jamie Harris.

"All our champions have been verified by TROBI and we've attached one of the Register's blue labels to each example to identify it for visitors."

Rich in character and history, Leonardslee's extensive tree collection, scattered across its 100 acres of woodland gardens and 150 acres of surrounding deer park, includes species from around the world - a hark back to Victorian times when Sir Edmund Loder, who established the site in the mid-1850s, concentrated on plant breeding and another previous owner, Charles Beauclerk, acquired plants from Kew that were new introductions into the country.

"Several ancient and significant examples are recognised as champions by the Register," Jamie continues, "the tallest or largest girth of their type in the county, Britain and Ireland or even the world."

"Prunus serrulata 'Alba plena' is one of our spring favourites. Found in the Daffodil Lawn, this huge spreading Japanese Cherry is over 100 years old and has the largest girth of its species in West Sussex at 247cm. In early spring, it is covered in pure white double flowers that last just a week."

And Leonardslee merits special distinction - numbering a 'monumental' tree among its august companions. "Our Algerian oak is registered as the tallest known specimen in the world," Jamie states proudly.

Setting up a champion tree trail is not necessarily about including every example on site - to create a safe pathway for members and visitors, owners and operators may have to exclude some champions growing in more remote or inaccessible areas of gardens, grounds or golf courses, David Alderman advises.

"The map we have prepared shows clearly where the champions are located and how to reach them safely," Jamie confirms.

Maintaining champion trees effectively depends on their size, accessibility and available resources. Leonardslee is luckier than many gardens in this last respect.

"We run a full-time tree team of three," Jamie confirms, "and they all have gained their climbing tickets, so we can address any tree care issues that may arise, whether they are champions or not."

"Local arboriculturalist Barry Houldsworth comes in from time to time to check the trees and we work with our local tree officer on specialist problems such as ground compaction."

"Leonardslee is a steep-valleyed garden and prolonged dry periods can affect tree root systems, but heavy layers of leaf mould that have accumulated over generations help lock in valuable moisture."

After working as assistant head gardener at The National Trust's nearby Nymans Gardens, and head at its Polesdon Lacey site in Surrey, Jamie is excited to be rolling out Leonardslee's CTT.

"This is the first garden I've worked in with champions where the focus is on plant collections and why they are world famous. Anything we can do to promote that, within the context of Leonardslee as a commercially-run visitor attraction, is to be welcomed."

Nothing's set in stone of course. The tree population across the South East particularly was decimated in the Great Storm, and the impact on mature trees continues to mount as storms and hurricanes become seasonal norms in the UK.

"If any of our champions fell in high winds, we would have to alert TROBI and amend the records accordingly," Jamie notes. "The Register runs a big team of volunteers - tree buff Ron came to check our collection - and he has been really supportive."

Storms are not the only threat to champion trees though. Onset of invasive insects, parasites, killer moulds and fungi as climate change grips the UK all pose potential perils that only constant vigilance can ward off.

The 50-strong team of volunteer gardeners at Cannizaro Park in south-west London, also keep tabs on its CT stock, besides recently getting stuck into some heavier landscaping and upgrade (making a bog garden, renovating the rose garden and transporting 50 tonnes of fresh topsoil to site by wheelbarrow) alongside council contractor Idverde, which is also responsible for formal areas. Further projects are planned by the park charity The Friends of Cannizaro Park.

Owned by the London Borough of Merton, the Grade 2* listed park has more than 60 trees on the Register, including more than 40 CTs, nearly all of those Greater London ones, with three exceptions, which are also England CTs. The park's self-styled 'tree team', volunteers Richard True and Piers Le Marquand, started labelling many of the champions, and other interesting specimens about two years ago.

"I sourced a specialist printer to supply labels that included Latin and common names, and a QR code to allow visitors to discover more information, such as when best seen and natural range," Richard explains. "Once scanned and read, tapping the text links to the park website for more details."

Ready to launch phase 2 of the labelling process after earmarking more trees, Richard is printing QR codes and preparing labels himself to cut costs. "We lost a few labels through vandalism but have replaced them to maintain a full record. David Alderman measured some of the trees when he visited and gave us a blue label for the British Isles champion, a sassafras."

Fancy checking out champions?

The Tree Register welcomes volunteers to help it keep tabs on the champion specimens it has listed - reverifying them and measuring new candidates for entry.

TROBI is also anxious to extend its seed collection programme to evaluate the local genetic base and help strengthen resistance to disease and climate change.

You can cover your own home patch or elsewhere - the choice is yours and TROBI may reimburse travel costs.

Email David Alderman at:david@treeregister.org

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Register roundup

Numbers 11,000 different taxa, including cultivated varieties.

Quercus alone has 620 genera and 651 cultivated species, hybrids and varieties, each with its own champion, as do the two native oaks.

Village sports and recreation grounds and across the country harbour tree champions.

The oriental plane at Woodstock Sports Club dates back to 1765.

Hayton Recreation Ground near Carlisle boasts the largest walnut tree in Cumbria