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.”BUILDING RESILIENCE
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.”FOREST GENETIC RESOURCES
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 forCompere John Leigh
Pemberton sets the scene.