Somerset site gives glimmer of hope for ash dieback disease

Trees in a Somerset plantation have survived with ash dieback (Chalara fraxinea) for far longer than previously thought possible, suggesting there may be potential to slow the spread of the disease in the British countryside after all.

Only ten per cent of the six thousand ash trees at the Holnicote plantation are showing any signs of the disease, despite having been infected for five years longer than any other tree in the UK so far.

The disease is present in one other small plantation nearby but doesn’t appear to have spread any further – which is at odds with Government predictions which suggests it should have spread further and infected more trees in this time.

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Weekly Witter: Pests and pestilence at the Chelsea Flower Show

Stop the Spread

No it’s not about butter…but tree pests, diseases and invasive species in general. This is the subject of a ground breaking garden at this year’s RHS Chelsea Flower Show.

“The garden will also have a black pool of water with a small living oak tree on a plinth in the middle at the end of the dead avenue.”

The National Trust has joined other organisations as a partner in the  Food and Environment Research Agencies  (FERA) garden designed by Jo Thompson to help raise the profile about the increasing threats we face but more importantly what we can all do about them.

The modern world we live in and our globe-trotting lifestyles combined with our increasing desire for ever more exotic food and plants is only increasing the chance of new pests and diseases and non-native species threatening our countryside, woodlands, forests and gardens.

“be prepared to be shocked… as there are dead (non living) trees at Chelsea for the first time…yes really!”

Since 2003 the National Trust has had to spend around £1m to deal with one disease alone, Phytophthora ramorum no small amount for a charity in these challenging financial times. But add in another 14 or so tree pests and diseases including the dreaded news making ‘Ash dieback‘ and the constant battle to keep our waterways and countryside clear of non-native species which sucks in vast amounts of staff time dealing with what is often a ‘fire fighting’ exercise, you can start to see why the Trust wants to help make a difference.

So was born the idea of working with others to raise the profile of these issues at the most famous garden show in the world, which in it’s centenary year is set to be a media show stopper.  But, be prepared to be shocked… as there are dead (non living) trees at Chelsea for the first time…yes really!  If you don’t believe me and you can’t go in person, check out our videos of the garden at www.nationaltrust.org.uk/chelseaflowershow or tune in to watch some of the television coverage which will be on BBC2 every evening of Chelsea week.  The garden will also have a black pool of water with a small living oak tree on a plinth in the middle at the end of the dead avenue.

But there is beauty as well as we know that this is not a lost cause and we can all do things to help prevent the spread of plant pests and disease.

Here are my top tips of some things we can all do to help ‘Stop the Spread’:

 Taking some simple steps when gardening or buying and planting new trees, can help reduce the risk:

Ask your nursery/garden centre for help: Wherever possible, buy home-grown trees and plants; they’re more likely to be “acclimatised” to our conditions and less likely to be a home for new pests and diseases or non native species. Don’t bring plant material home from holidays abroad.

Buy small and watch it grow.  Semi-mature trees often grown overseas pose a higher risk of introducing pests and diseases. So be patient and plant smaller trees instead – they’ll often establish quicker too.

Right plant; right place.  A healthy tree or plant is less likely to succumb to disease – try to match a tree to its preferred location, type and size of tree, soil type, available space.

Help it to establish itself.  Feed your tree but avoid over-feeding which can lead to vulnerable soft growth. Consider a mycorrhizal fungi planting treatment to encourage healthy root growth. Use a good stake and tie, but don’t strangle your tree!  Lower leaves in contact with the soil risk picking up disease, so remove them when you plant or use a good mulch.

Give it room to grow.  Space trees as widely as possible to ensure good air movement and reduce humidity.  Prune out any dead and diseased branches and dispose of the waste sensibly.

Keep clean.  Pests and disease are easily spread on soil and plant debris attached to footwear or on tools like secateurs and saws, so clean mud and leaves off regularly.

Don’t stop planting. The worst thing we can do is to stop planting trees. Simple measures like those above will help protect our beautiful woodlands and forests in these difficult times.

 Dispose of garden waste responsibly. Compost your waste properly or dispose of in a responsible way. Don’t dump garden or pond waste in the countryside or water courses

Top tip: When buying look for: healthy, vigorous trees and plants, not pot bound, not too much soft growth. Avoid signs of dieback, leaf spotting, insect infestation and mould growth. Look out for other non -native species species hitching a ride.

The team hard at work

The team hard at work

  • Ian Wright is the National Trust’s Gardens Adviser based in the South West of England.  He advises on all things horticultural at the 30 great gardens in the South West. He has built up an extensive knowledge of plant and tree pests and diseases over his 26 years working for the Trust and in more recent times produced guidance for staff aimed at preventing the spread of pests and disease.  Ian describes himself as ‘almost a tender perennial’ and now ‘lacking the appetite for true British winters’ after working in the favoured climate of the South West for so many years.  Potential sponsors take note… Ian’s greatest dream is to design a ‘Gold winning’ show garden for the National Trust at Chelsea…..any offers?
  • The Weekly Witter is a regular weekly mouthpiece for our many specialists to talk about the news, current affairs, and what’s on their minds at the moment.

Ash Dieback and the threat to our cultural trees

Brian Muelaner – Ancient Tree Adviser for the National Trust gives his overview of ash dieback and how it could affect our ancient trees:

One would have to have been living in a bubble over the past six months not to be aware that Britain’s ash trees are seriously at threat from Chalara fraxinea, a fungal pathogen commonly called ash dieback. Since this fungus was first identified barely 10 years ago it has swept across northern Europe from Poland causing massive dieback of ash trees of all ages and sizes. It now appears to be deeply embedded within the countryside of England and to a lesser extent Scotland and Wales, putting at risk some of Britain’s most important trees.

Since ancient times, well before the Roman’s came to Britain, ash trees were important for providing ‘tree hay’, particularly in upland situations where the severe climate made it difficult to produce traditional hay. This practice has taken place in upland regions across Europe. Trees were pollarded every three to five years in the summer, removing all of the tree’s branches above browsing height at around eight feet. The branches were collected and tied into faggots and stored under cover till winter when they were fed to the stock.

Muelaner

Ash Pollards in Sweden

The practice still survives in some countries, such as in Sweden, through grant aid to help preserve these biologically and culturally important trees. Farmers still regularly pollard ash trees to feed to their cattle in winter. Ash leaves have a much higher level of protein than traditional grass hay.

The landscape in some of the dales in Cumbria such as Langdale and Borrowdale is littered with ash pollards which are many hundreds of years old, yet these are small hollow trees, kept small from the repeated cutting over centuries. The Trust has restored the practice of pollarding these old trees to prevent their collapse as the limbs become too heavy for the fragile shells of the trunks to be able to support. We have even recorded ash pollards on farms as far south as in east Cornwall, which were almost certainly historically managed to provide tree hay. In Cornwall the wet climate makes producing traditional hay a risky business, so before the advent of silage tree hay was a safer option. 

At Dyrham Park in South Gloucestershire there are several dramatic ancient ash pollards which are the sole remnants of an older landscape now incorporated within the designed deer park. These very fragmented old trees are all that remain of a time before the great landscapers created the beautiful parklands we know and love.

Down in Branscombe in East Devon the ancient ash pollards were used for a very different but equally important purpose. Here the trees’ branches were cut on a longer cycle of every 10 to 15 years to provide fuel for the village bread oven. We forget just how significant a role trees have historically played in providing us with warmth and cooking before coal and electricity.

Muelaner

Ash pollards in Brascombe

All of these trees could disappear in the next decade or two as Chalara fraxinea slowly sweeps across the country. We must continue to survey and record these wonderful old trees as quickly as we can before they are sadly lost forever.

  • Brian Muelaner – Ancient Tree Adviser for the National Trust. I advise on how best to manage these special trees to preserve their natural lives. I am often among trees many hundreds of years old, some are a thousand years or more and still quite healthy. I am coordinating a national survey of all ancient and notable trees on Trust land. To date we have recorded a remarkable 25,000 trees and still have many more properties to survey. I am also compiling an inventory of the hundreds of Trust avenues.

“Government plan for ash dieback could buy us time,” says National Trust

In response to the Government’s control plan on ash dieback announced today, Dr Simon Pryor, Director of the Natural Environment at the National Trust, said:

“It is too late to eradicate this disease, but this plan could buy us time.  If we – Government, landowners and foresters – can all work together to reduce the rate at which it spreads across the country we can find ways to ease its impact on our landscapes and wildlife.  But we must use this time energetically, to explore every possible way in which we can increase the resilience of our trees and woods. 

“The National Trust will be inspecting and where necessary removing and replacing all recently planted ash trees on our land, and we call on everyone who has planted ash trees in the last few years to do the same. 

017 Wood pasture with pollards“This is a pragmatic plan, but there are still many unanswered questions about this disease.  We are pleased that the Secretary of State has said that plant health was one of his top priorities.  But it is vital that he does actually make new resources available to enable Defra, FERA and the Forestry Commission to deliver this plan, rather than rely on others. 

“Once these diseases become established it is clear we can’t eradicate them.  So the one really big lesson from this disaster is that we must stop importing pests and diseases in the first place.  The Government must show real leadership by improving controls over the trade in plants and biosecurity at ports.  We must not be wringing our hands again in a few years time when yet another devastating pest or disease is found.”

Further detail about what the National Trust will be doing

Speaking about what the National Trust will be doing over the coming months Dr Pryor commented: “The Trust has already removed thousands of young infected trees that we had planted.  We will continue our inspections this summer and where appropriate will be removing and replacing infected young trees. 

“But one thing that we and other owners must not do is prematurely fell any older trees simply because we think they might be infected.  We need to ensure they remain safe, but there is still a chance some of these mature trees will pull through.  It is much better for wildlife for the trees to gradually decline than be felled prematurely.  

“We will also be making our woodland available to researchers so they can carry out trials and learn more about this disease.  We have also offered our plant conservation centre as an additional resource for growing disease free native ash which can be planted once conditions have improved.

 “This disease has revealed some alarming practices in the nursery trade, and we are taking a long, hard look at how we can ensure the young trees we plant are healthy and genuinely home grown.”

Second case of ash dieback Chalara fraxinea confirmed on National Trust land in Northern Ireland

Tonight, the National Trust has announced that the second case of ash dieback Chalara fraxinea, has been confirmed on its land in Northern Ireland, at a three and a half hectare site on the North Antrim coastline. 

The first was confirmed at Borrowdale in Cumbria this morning.

Ian McCurley, regional forestry adviser said: “Unfortunately ash dieback has now been confirmed at one of our Northern Ireland sites.  We are devastated by this news; it is a really sad day for our woodlands here.

“There are an estimated 3.5 hectares affected at Runkerry, right beside the Giant’s Causeway, World Heritage Site on land we acquired a few years ago.  Around 2,000 young trees, planted in March this year, have today been confirmed as carrying the disease.  We have acted swiftly alongside officials from Forestry Services to remove and burn the trees in the affected area.

“Our tree and woodland experts have been working closely with the Department of Agriculture and Rural Development (DARD) to survey the region looking for signs of the disease, and sadly, it was only a matter of time before we had a case confirmed.

“The ash trees will be replaced with other species, but our main objective is to do everything possible to try to protect as many of the ash trees as we can in the woods, parks, gardens and farmland that we care for.”

“We will continue to implement best practice, as advised by our forestry colleagues at DARD.”

First case of ash dieback Chalara fraxinea confirmed on National Trust land

The National Trust has confirmed that the first case of ash dieback Chalara fraxinea has been found in new plantings on a four hectare site of its land in the Borrowdale area of Cumbria. 

The conservation charity is one of hundreds of landowners that have confirmed the presence of the disease on its land over the past couple of weeks.

Ian Wright, plant health specialist at the National Trust, said: “Unfortunately ash dieback has now been found at Watendlath in the NorthLakes. 

“This is the first of several sites where suspected cases have been found on Trust land over the past couple of weeks, with the others mainly in the east and south-east of the country.

“Our tree and woodland experts across the country have been working closely with the Food & Environment Research Agency (Fera) to survey the country looking for signs of the disease, and sadly, it was only a matter of time before we had a case confirmed.

“As a precautionary measure, we started to remove and destroy the 1,000 new plantings, which were less than a metre tall, ahead of diagnosis, to try and safeguard nearby veteran ash pollards – some of which are over 400 years old. 

“The ash trees will be replaced with other species, but our main objective is to do everything possible to try to protect as many of the ash trees as we can in the woods, parks, gardens and farmland that we care for.”

The National Trust cares for 25,000 hectares (61,776 acres) of woodland and forest throughout England, Wales and Northern Ireland with many special places, beautiful woods and ancient trees at risk because of this disease. 

Mr Wright added: “Many of our wooded landscapes may well be dramatically changed by this disease, and we are particularly concerned about the loss of the some of the hundreds of veteran ash trees that we have in our woods and parkland.

“We will continue to implement best practice, as advised by The Forestry Commission and Fera. 

“All the places we look after remain open to the public as normal, but like other landowners we’re advising visitors to follow some simple steps that may help reduce spread of the disease.

“This includes keeping to marked paths when walking through woodland and cleaning mud and leaves from footwear and bike tyres after visiting the countryside.

“Thankfully during the winter and spring the spores are least likely to spread, so we have some breathing space.  We are investigating whether there is any other action we can take to limit the spread next spring or whether there are ways of increasing the resilience of our trees.“

National Trust reaction to the Government’s action plan for tackling ash dieback Chalara fraxinea

Commenting on the Government’s action plan for tackling ash dieback Dr Simon Pryor, Director of Natural Environment at the National Trust, said: “This disease poses a major threat to special places throughout the country and is potentially more devastating to the landscape than the loss of Elm in the 1970s.

“We welcome the Government’s action plan, particularly in identifying clear objectives that will help reduce the spread of the disease.  

“We agree with their immediate commitment to destroy infected young plants and to reduce the rate of spread.  But we are surprised that the Government is saying that it will not be possible to eradicate the disease. 

“Given our limited understanding of this disease in this country, we believe we should keep an open mind as to whether it may be possible to eradicate it, or at least contain it within the core area in the east.  

“Even if we only delay the spread of the disease this will buy us valuable time to establish the next generation of trees and also investigate other means of increasing resistance of mature trees.

“Although the National Trust relies mainly on natural restocking of the 25,000 hectares (61,776 acres) of woodland in our care, we are putting in place a rapid programme of tracing, checking and destroying any infected newly planted stock that may have been brought in.

“We welcome the protection for veteran ash trees as they provide immensely important habitats for a huge range of plants and animals and are an important part of the UK landscape.  We are pleased to hear the Government stating that it will not require felling of such mature trees at this stage.

“As part of this process we will help identify signs of resistance in ash trees and welcome the opportunity to work with scientists in identifying resistance that may be possible to build up in the UK stock. 

“We welcome the Government’s commitment to further research, but it is vital that funding for these new actions is not simply diverted from existing research on plant health. 

“This is a major new national disaster for our countryside and it will require new resources to tackle it effectively.”

For more information, images, or to request interviews with Dr Simon Pryor, Director of Natural Environment or Ian Wright, Plant Health Specialist please contact Jeannette Heard in the National Trust press office on 01793 817706 or 07884 473396 or email jeannette.heard@nationaltrust.org.uk

National Trust statement on Ash Dieback Chalara fraxinea

Following the discovery of the deadly Ash Dieback Chalara fraxinea disease in the East of the country, the National Trust welcomes the fact that the Government has now introduced the ban on the importation of ash trees into the UK which came into force yesterday. 

The Trust is also pointing to the need to provide sufficient investment into tree disease research and more restrictions on plant movement.

It is also working closely with other key organisations and is prioritising the checking of ash trees thought to be currently the most at risk in the South East and East of the country.

Ian Wright, plant health specialist at the National Trust said: “We welcome the Government’s ban on the import of ash trees into the UK.  We are very concerned about what effect this disease will have on a key historic species – and on our landscapes. 

“As well as the threat to ash trees and woods across the country, we are particularly concerned about the risk to some of the magnificent old ash trees in our parkland and ancient woods. We have at least 300 of these on our register of veteran trees and many are over 300 years old. If this devastating disease took hold it would radically change some of our most special landscapes and places forever. These ash trees are also incredibly important for the rich flora and fauna only found on such ancient trees, which includes rare lichens, mosses and wood boring insects.

“A high level focus on tree disease is needed with more funding made available by Government for urgent work on how diseases spread and how to develop greater resilience in our woods.  We also believe there may be a need to put greater restrictions on International European trade in plants to reduce the risk of such disease spread.

“We are working closely with the Forestry Commission (FC), the Food & Environment Research Agency (Fera) and the Woodland Trust among many others to keep abreast of developments, and will take on board any guidance that is issued.

“We are currently checking the sites we believe to be at most risk in the South East and East of the country, prioritising where our most important ash trees are.

“We have already halted any planned ash tree planting on our land and are now weighing up the risk to ash trees of planting of other species that might be carrying the disease.  Our outdoor teams are already undertaking surveys of their ash trees while leaves are still on them to see if any are showing signs of the disease.  We will be referring any suspected cases to Fera and FC.

“We hope the Government will respond to the calls for an urgent summit to discuss ash dieback.”

Press wishing to interview Ian Wright should contact Jeannette Heard in the National Trust press office on 01793 817706 or 07884 473396 or email jeannette.heard@nationaltrust.org.uk

Notes:

1.  There is an estimated 80 million ash trees in the UK – a third of our entire tree population.  Ash is found throughout the country and grows in most soil types.  It regenerates profusely, and as climate changes, oak and beech woods are likely to become more dependant on ash in the future.

2.   In the early 1990s severe dieback of ash (Fraxinus excelsior) was noted in north-eastern Poland.  Trees of all ages were affected and typically displayed small necrotic patches on their stems and branches which later developed into girdling lesions resulting in wilting of leaves, tip dieback of branches and mortality of trees.   Initially, the cause(s) of the dieback were unclear but a species of Chalara was frequently isolated from lesions on symptomatic trees and by the mid-2000s this was recognised as both a new fungal species Chalara fraxinea and as the primary pathogen involved in the causation of ash dieback.

3.   Ash (Fraxinus excelsior) in Britain is the third most commonly recorded broadleaved species highlighted in the most recent Census of Woodlands and Trees, and is the second most widely planted broadleaved tree. Ash is found on a huge variety of site types, calcareous/acid, lowland/upland and throughout the UK.  Ash is an important tree in terms of its timber value and a key component of many habitats and feature of most landscapes.  It is also thought that ash will become a much more extensive and important element of many existing woods as it regenerates profusely and does not appear to suffer serious bark stripping by grey squirrels as do many other native broadleaved species. Because of these valuable characteristics, existing beech woodlands, PAWS restoration areas and even oak woods are likely to become more dependant on ash to survive as healthy and productive broadleaved woodlands.

4.   Since the early 2000s, Chalara fraxinea has spread rapidly across continental Europe with ash dieback now reported from the majority of European countries.  During 2012 interceptions of ash saplings infected with C. fraxinea, were found both in a number of key UK nurseries and shortly after out-planting. The outbreaks/original infection might have occurred as far back as 2009.

5.   Despite the detection of ash dieback in out-planted ash saplings, the pest is not yet considered to be established in the natural environment in the UK, since the infected plants are likely to have harboured the disease prior to planting and there is currently no evidence to indicate that transmission to other trees has occurred. However, the rapid establishment of the pest throughout many European countries, and the existence of appropriate growth conditions for the pest suggest that in the UK the potential for establishment is high and therefore the risk very high.

6.   The National Trust looks after 25,000 hectares (61,776 acres) of woodland and forest. We also conserve historic parks, gardens, commons and pasture-woodlands, where individual ancient ash trees are a highly prized resource – for their beauty and for the plants and animals growing on them – many of them direct descendants from the original Wildwood. The loss of these individual ash trees would mean the entire loss of these species from a site and even a region.