THE Future Trees Trust Annual Supporters Day 2019 was held at the 560-acre Royal Botanic Gardens (RBG) Wakehurst in Sussex, in the Millennium Seed Bank’s seminar room. It was a fitting venue for a morning that saw the launch of two new strategies, ‘A Strategy for UK Forest Genetic Resources’ and the ‘Ash Research Strategy’.

Compere for the day John Leigh Pemberton set the scene: “Dead and dying ash trees punctuate south-east England’s skyline. Increasing timber prices, significant disease pressures and the failure to plant at the rate needed are balanced by a strong recognition of the social, environmental and climate change benefits that forestry can bring. What we talk about today is immensely important.”

Director of RBG Kew, Richard Deverell, welcoming attendees, explained: “Kew’s collaboration with the Future Trees Trust (FTT) springs from a shared objective: to understand and conserve the genetic diversity of this nation’s native trees.” 

The Millennium Seed Bank (MSB) is a gene bank conserving UK and international seeds collections.

“Launched in 2013, the UK National Tree Seed Project has 74 species of UK native trees and shrubs taken from 9,500 trees, conserving approximately 14 million individual seeds. Over 30 organisations have contributed to the project and the collections (and associated data) are available for research and conservation.”

The ‘Strategy for UK Forest Genetic Resources’ is co-authored by RBG Kew, the Centre for Ecology and Hydrology, FTT, Forest Research and the Woodland Trust. Supporters include the Forestry Commission, Confor, Natural England, Scottish Natural Heritage, Natural Resources Wales, universities, botanic gardens and members of the devolved administrations. “RBG Kew will continue contributing to projects to understand and conserve national (and global) forestry and to DEFRA’s Ash Research Strategy,” said Deverell.

Keynote speaker Lord Gardiner, Minister for Rural Affairs and Biosecurity, said: “Trees are vital natural assets contributing to our food supply, the rural economy (including timber) and habitats vital for wildlife and biodiversity. They help absorb air pollution, sequester carbon, cool our environment, reduce flooding, provide enhanced landscapes and are crucial for recreation and wellbeing. Trees have shaped our landscape and our history. We need trees.

“Government commits to protecting and enhancing natural landscapes and habitats for future generations. The 25-Year Environment Plan sets out commitments to develop a new Northern Forest, to plant 11 million trees in woodlands and a further one million trees in urban areas. The Urban Tree Challenge Fund is a response to HM Treasury releasing £10m in the 2018 autumn budget. I hope people will unite and form a planting army under Tree Champion Sir William Worsley’s banner.

“Since 2012, government has invested more than £37m in plant health. The Tree Health Resilience Strategy (2018) contains four Environmental Goals: Extent – in terms of P&D we need an increase in the extent of trees, woods and forests; Connectivity – more trees in hedgerows and other habitats providing corridors between woodlands; Diversity – enhancing the genetic and structural diversity of our treescape; and Condition – encouraging healthier trees, woodlands and forests.

“This strategy recognises the importance of understanding and conserving genetic diversity, providing the potential to adapt to changing environmental conditions through natural selection, and for future society to select and develop characteristics – not yet recognised – for different products or services.

“The ‘Strategy for UK Forest Genetic Resources’ concerns tree and shrub populations uniquely adapted to UK growing conditions. The UK Plant Health Risk Register contains over 1,000 pests and diseases: 300 are recognised as attacking trees [and 29 attacking ash]. Ash dieback (ADB) is ‘high risk’ and emerald ash borer (EAB), not yet present in the UK, is moving west from Russia towards Europe.”

Since 2012, government has invested £6m in ADB research. “We have sequenced the ash tree genome and that of the ash dieback fungus. The Tree Council launched a Toolkit (since downloaded 11,500 times) to manage ADB impacts on the ground. This (MSB) building safeguards the genetic diversity of native ash populations, 2 million seeds taken from 700 mother trees, capturing (approximately) 90% of the genetic variation of ash trees across the UK.

“The ‘Ash Research Strategy’ ensures management of the immediate impacts of ADB and an optimal response to any incursion of EAB. Future research themes will develop around the restoration of our landscape.

“DEFRA funds several key research activities, including the ongoing screening by Forest Research and the FTT for ash trees tolerant to dieback. In 2020, grafts from these trees will be planted in a UK Ash Archive, a living collection of tolerant trees nurtured for a future ash breeding programme.

“Funders, researchers, practitioners and policy-makers all have roles to play in understanding, conserving and managing our trees. It is this generation that must take action, heightening biosecurity and committing to research to provide the solutions. Mentioning oak for a moment, 2,200 species rely on the oak tree for their habitat and existence. This figure starts to crystallise why the tree is absolutely vital to the whole of our ecosystem. We rely on the expertise of the people in this room, so that in this country and across the world, we can say our generation cracked it.”

DEFRA’s chief plant health officer Nicola Spence outlined the ‘Tree Health Resilience Strategy’, the first strategy to come out of the 25-Year Plan. The vision, ‘to build resilience of England’s trees, woods and forests 
. . . by mitigating and minimising the impact of pests and diseases (P&D) and improving capacity of trees to adapt to changing pressures.’

“The value of whole-system assets – the treescape – at risk is estimated at £175bn, with an annual value of £4–5bn,” she said. “For ‘resilience’, we looked at the threats (exacerbated by global trade and travel, airborne threats and pathogens then evolving/cross breeding) and environmental pressures (climate change, air pollution, land use change, invasive species (deer/squirrels)) that can increase a tree’s susceptibility to P&D.

“From the four goals outlined by Lord Gardiner, we developed three ‘resilience outcomes’ for treescapes: resistance; recovery and response; adaptation.”

She said these resilience outcomes had led to a national action plan with priority actions including horizon scanning (for EAB (Agrilus planipennis)), contingency planning and grant schemes. Meanwhile, the case study for ash has resulted in the Ash Research Strategy.

“The ash trees saved from mass screening trials look healthy,” she said. “All devolved nations and delivery organisations are involved in the EAB Preparedness Board. Working in partnership is critical. We all have a responsibility and there are things we can all do.”

Seconded for a year to DEFRA, Clare Trivedi (Kew’s UK conservation partnership coordinator) outlined aspirations for the ‘Strategy for UK Forest Genetic Resources’, assisted by Stephen Cavers (Centre for Ecology and Hydrology) who projected a photograph, taken from space, of birch pollen dispersing from continental Europe all the way to Scotland, demonstrating how airborne P&D spread.

Stephen said: “Genetic diversity provides the raw material for adaptation within species to meet new challenges. Ash trees with tolerance will prosper, providing the raw material to improve the species and produce more productive trees.”

Clare said: “A strategy for the UK, for native species and those bred or naturalised to UK conditions, helps us to understand genetic diversity and to effect in situ and ex situ conservation of our trees.”

Aspirations include a steering group to coordinate the many activities and organisations working with UKFGR (UK Forest Genetic Resources).

Auditing ex situ collections (in seed banks, field trials, arboretums and botanic gardens) will show what material is already held. Collating the research to date will highlight knowledge gaps and stimulate further research (and funding) topics. This work will help in tree planting and provide a framework for reporting into international structures.

Clare said: “Establishing a network of gene conservation units, woodlands representing distinct genetic variations of particular species managed to promote regeneration and continued adaptation to changing conditions, has begun with the ancient Caledonian pine forest at Beinn Eighe (National Nature Reserve). Oak, horse chestnut and sweet chestnut cannot be seed-banked using conventional techniques and we have to consider how to manage that.” The next step is to develop an action plan.

The Future Trees Trust, a consortium of partners funded mostly by private charitable donations, is the UK’s only tree improvement charity.

“We want to grow trees more economically attractive to landowners; those with a better chance of survival and increased timber yields,” said chief executive officer Tim Rowland. “Why? New planting has plummeted; so has hardwood management and timber production. Woodland wildlife species have also declined by 34 per cent. HMS Victory is reputedly being restored with French oak.”

Working with timber-producing species (ash, birch, cherry, walnut, sycamore, sweet chestnut and oak), breeding improvement trials are already underway, using material collected from ‘plus trees’ – “those trees adapted to local climate, pest and disease free, quick growing with straight, circular stems and fine branches”.

In one Californian breeding improvement programme, “birch got out of the ground quicker, with reduced establishment and long-term maintenance costs, shorter rotation times, probably producing higher-quality timber. We hope demonstration plots in the UK will convince the forestry sector.

“Help us to change the planting and granting system to ensure improved material is used. Question provenance and use plants grown from improved seed or from a qualified seed stand.”

Dr Jo Clark explains the FTT hopes to bring to market improved seed (qualified and tested) for key timber species by developing clonal seed orchards (CSOs). “In January, we planted four CSOs for oak, Q. petraea and Q. robur. We cannot seed-bank acorns so these orchards are an important genetic resource, accessible to anyone.” 

With the Woodland Trust, the FTT is working on a sustainable seed source project for minor species (hornbeam, lime), and with Forest Research on modeling where (geographically) seeds from clonal orchards should be deployed.

Both the Living Ash Project and Forest Research’s Mass Screening Trails gathered material from tolerant trees to graft and grow on. In January 2020, grafted trees will be planted out on the public forest estate, forming a living ‘UK Ash Archive’ from which more selection and testing work for tolerance or resistance will be pursued.

Over 25 years, the FTT has selected 1,400 ‘plus trees’ for seven key commercial broadleaves, established 16 CSOs for sycamore, chestnut, silver and downy birches, cherry, ash and 15 BSOs (breeding seed orchards, a form of progeny trial combining a ‘testing’ phase with the ‘seed production’ phase) for oak, sycamore and silver birch.

Only two years old, the National Tree Improvement Strategy has 21 member organisations, from tree breeders, academics and research purchasers, to foresters, seed merchants, nursery managers and sawmillers (who want trees bred that are fit for purpose).

Chair Steve Lee said: “Tree breeding and improvement is the best way to retain and enhance our woodlands, in terms of productivity, resilience (to biotic and climatic threats), genetic diversity and site adaptation.

“Woodland owners, forest managers and policy-makers must know that there is a choice of planting stock and be encouraged to plant the best material – perhaps through better grants – knowing that what they plant has the resilience to make it through a complete rotation.”

Partners are already working together to achieve research goals. ‘Plus trees’ are being selected for a wider range of species and new DNA techniques developed to speed up the whole breeding process. An online database of FTT and Forest Research tree breeding work is in the works. The NTIS (National Tree Improvement Strategy) website will be available soon. 

Tree Champion Sir William Worsley concluded: “Words of wisdom have been spoken. Thank you to Kew for hosting and for their work and that of the co-authors and supporters in developing this pioneering Strategy for UK Forest Genetic Resources.

“Lord Gardiner mentioned our aspirations. I am impressed with the work I have seen around plant imports. More must be done right across the rural sector on the issue of biosecurity and we must manage it realistically.

“I was fascinated – terrified by the slide showing the movement of birch pollen across Europe on the wind. It is how ADB got here. The Ash Research Strategy is ground-breaking work, thank you to all those involved.

“To finish, I like Lord Gardiner’s planting army. Partnerships working together – government, the FC, the private sector and the third sector – all planting trees with improved provenance to grow trees of economic value made into products which lock up carbon. Great work. Please carry on.”

Future Trees Trust:
RBG Kew Wakehurst: