An ironic twist, that ash dieback should rear its head in the UK just as all trees are dying back for the winter, making it much harder to detect. It was with a heavy heart that we realised that we, like all small woodland owners, were vulnerable to this new disease which has made its way across the channel to the UK. Betty’s Wood is particularly vulnerable, because we have planted a significant number of ash trees (about 10% of the trees are ash), and because Chalara dieback affects young trees more severely, and because the nursery from which we got them has had an outbreak of Chalara this year (although, thankfully, none of the batches we bought from them were affected).
We were extraordinarily careful with the provenance of our trees: not just UK provenance, but we were careful to ensure that they were UK grown too. It is very easy to cast blame on people planting trees for not checking the provenance, but it is also very easy to be misled into thinking that trees come from the UK when they don’t. More needs to be done to ensure that the provenance of each tree is clear, via a passporting system to ensure we know where the seed came from and where it has been grown at each stage of development.
It is also easy to blame politicians of all parties for failing to take action: the fact is that blame will not solve the problem we have now, of dying ash trees, spreading disease, and the prospect that ash trees will all but disappear from the UK until trees that are resistant to the fungus emerge. I am sure in hindsight, many people could and would have acted differently – politicians may have taken action to ban imports sooner, movement of ash trees around the country could have been stopped sooner, the wider countryside could have been surveyed sooner, people planting trees could have asked more questions about where they came from, and those supplying trees could have been more open about where they came from too. Lots of people made mistakes. What is not needed is a lot of mud-slinging and blame-casting. Instead what we need is a real, considered, careful plan so that this issue does not arise again with another species of tree.
This has led many to ask whether tree-planting is needed at all. Can’t we leave it all to natural regeneration? In many cases, yes, and perhaps there will now be more support and grants for people who wish to allow woodland to generate naturally, rather than plant, and also for those who wish to collect and sow natural tree seed and allow it to grow in situ. At present the grant system is skewed towards planting. But there are clearly places where planting is needed. Like it or not, trees are a crop, and planting will help to produce a crop that is in heavy demand for wood-fuel and wood products. There is also a need to improve habitat connectivity, and this cannot always wait for natural regeneration, which may take decades. Then there is the need for landscaping along our infrastructure and in urban areas and building developments – trees are good for health, and they won’t just happen in many of these areas unless they are planted.
But there are messages from the crisis. First of all, it is very important not to plant huge stands of one species. Yes, we planted a lot of ash (and also have a lot of ash regenerating naturally around the edge of Betty’s Wood), but we planted a whole range of species. This means Betty’s Wood will be resilient, and should we lose the ash trees it will not be a disaster (except for ash-specific species). Second, it is important not to go round destroying ALL ash trees in the vicinity of an infected one – a few of those trees will show an innate level of resistance. In countries affected by Chalara for a number of years, some trees have survived. We need to look at the diversity of the trees, young and old, and work out why they are surviving, and preserve those genetically resistant to the fungus. We cannot do this if we kill all the ash trees. Third, we need to stop cutting back the expertise we have in plant pathology, mycology, arboriculture and tree disease research – cuts will not solve this problem, nor will contracting out to the private sector. This is an activity of national importance that needs public funding, and needs to remain in the public sector, with support from the taxpayer. The expertise is already at a critically low level – it needs to be retained, nurtured and developed to address the issues of future plant diseases. Or we run the risk of failing to learn from this crisis, and of the same thing happening again, but to a different species of tree.
If 90% of our 700 or so ash trees die, then we will still have 70 ash trees that do not die from which to repopulate our site. That is a good number of trees which will show genetic diversity, and from which a resistant population can emerge. We just hope that Chalara dieback can keep away until these little trees are old enough to produce seed, so we have a seed bank in the ground.
At present there is no sign of Chalara in any of our little trees, or in any of our few mature ash trees, but that may change. Like it or not, Chalara will spread on the wind, on the feet of birds, on the feet of animals. That cannot be changed. Chalara is a crisis, but also an opportunity. An opportunity to get the resources that are needed into plant research, changing nursery practices, dealing with biosecurity, looking at ways to raise a diverse and resilient tree population.
In the end, most of our ash trees are likely to be lost. We hope not all of them. In the meantime, we will do our best to keep them healthy, free from disease, growing and producing seed. The seed is the future.