As Manchester Museum’s Extinction or Survival? exhibition is drawing to a close, and in commemoration of the International Day of Forests on 21st March, today’s post by Bryony from the Visitor Team looks at the Elm, once a common tree throughout English countryside, its numbers were sadly devastated with the outbreak of Dutch Elm Disease.
For more about botany, have a look at the Curator’s blog, Herbology Manchester.
Extinction or Survival? is open now, but hurry! It only runs until 20th April 2017. You can join the conversation now at #MMExtinctionSurvival.
Remembering the Elm
The English elm was once the archetypal tree of the British countryside, being the most numerous and one of the most distinctive trees, with a ‘figure of eight’ bough shape, reaching heights of up to 30 metres and towering above many other British trees. Other elms such as the European white elm and the wych elm were also a true staple of the British landscape.
Pictured in ‘Familiar Trees’, illustrated by W.H.J. Boot in the 1890s, showing the typical countryside scene of an elm tree – an English elm on the left, and a Wych elm on the right. (Image from: darvillsrareprints.com)
The English Elm
The English elm was long thought to be a true British tree, but recent research has shown otherwise – it seems to have come to the UK thousands of years ago with the Romans. Our actual native elm appears to be the wych elm, named for the Old English wice meaning pliant or supple rather than for witches! Due to the tight grain of the wood being so resistant to water, it was put immediately to good use as some of our early water mains and sewage pipes, starting as early as the 13th century. Between the 16th and 18th centuries the industry underwent a boom and, of course, most of those pipes were elm – but this is far from what elm is most famous for.
Dutch Elm Disease
Most people in the UK will have heard of Dutch Elm Disease, of course. In fact, most people in the entire Northern hemisphere will remember (or have relatives that remember) this disease. Dutch Elm Disease is another misnomer, as it didn’t originate in the Netherlands either – it was discovered by Marie Beatrice Schwartz in 1922, who was from the Dutch East Indies (present-day Indonesia), and at the time was a PhD student in the Netherlands beginning her career as an eminent tree pathologist, so ‘Dutch Elm Disease’ became its name. This disease has devastated the elm population in England, with an estimated 30 million trees lost. This of course has had an effect on the wildlife that depended on it too – the white letter hairstreak butterfly, for example, has declined by 96% since 1976.
Left: English elm affected by Dutch Elm Disease, showing clearly the infected branches (image from: en.wikipedia.org). Right: white letter hairstreak butterflies, Nature’s Library, Manchester Museum.
A milder form of the disease had been noticed in previous decades; it was caused by the sac fungus (Ophiostoma ulmi), carried by the elm bark beetle. They usually prefer mature trees, eating into the bark and transmitting the disease which prevents water from being transported up the trunk and to the branches. The aggressive form that arrived in the UK in the 1960s and did the most damage was a completely different strain, and one that our long-established trees could not survive. This newly arrived form of the fungus is known as O. nova-ulmi.
The spread of people (and thus timber, crops and non-native garden plants) across the world has led to a great number of diseases being imported that British trees are simply not used to. As well as Dutch Elm Disease, we have Sudden Oak Death, Ash Dieback, Chestnut Blight, Red Root Rot …
A sudden oak death! No, this is one of our dried specimens, showing silk-button spangle galls on oak leaves. Nature’s Library, Manchester Museum.
Similar things are happening, of course, with all kinds of species all around the world, but the diseases caught by plants often have a very direct effect on us humans, too. After all, we aren’t immune to what happens to the natural world – without plants, we could not exist. There have been plenty of times throughout history that showcase the damage plant diseases can do.
Plants and Humans
The most famous example for our part of the world is probably the Irish potato famine – the fact that 1 million people starved was due to a variety of factors causing a dependency on that crop, but similar situations can be found in many other places around the world today, such as with rice crops in parts of Asia. Even in areas with access to a variety of crops, food security is a hot topic, and one that is ever more important with the current population boom and the movement and export of food around the world.
Brussel sprout seeds, The Study, Manchester Museum; rice, potato and tomato specimens, Nature’s Library, Manchester Museum.
Plants are not just depended on by humans, they also provide the foundation for the vast majority of life on earth, with the exception of very specialised environments such as sulphurous deep-sea vents. They provide food, oxygen, habitats, water, as well as slightly less obvious functions like holding together riverbanks and providing us with building materials and fuel. They improve our lives as well – studies show that exposure to a green environment (and mature trees in particular) has a long-lasting effect on our mental health and well-being.
And it is for precisely this reason that we develop such a deep connection to the trees that form part of our environment. There’s a good reason why two of the ten trees shortlisted for England’s Tree Of The Year contest 2016 were elms – they are a rare sight in the UK these days, and many people have not seen them since their youth, so when they do see an elm there is that rush of familiarity and connection that I’m sure we all feel with our favourite trees.
Can we change our future?
One of the problems facing the plant kingdom across the world is the lack of interest in areas of research like plant pathology (the study of diseases like these that affect plant life), despite the fact that it has such a major effect on our environment and food supply. The British Society for Plant Pathology estimated in 2012 that there are fewer than ten active researchers in the field in the UK today. Considering how much we value and treasure our plant life, that is shockingly low – life as we know it depends on plants, and that includes many of our rarest species as well as people. But plants should be enjoyed for their own sake as well; the English elm had no major economic importance, and no irreplaceable function, it was simply a thing of beauty that is now almost gone, and we are all poorer for its loss.
But of course, we can do something about this. For creatures like the panda, it is easy to get popular support and fund the conservation project to save it, but if we all did the same for plants, then who knows what we could achieve! It’s a smart move for us, and a smart move for most of the other life on Earth, too. Remember the elm, and take a little time to appreciate the amazing plant life of this world.
English elm specimen, ‘Extinction or Survival?’ exhibition, Manchester Museum.
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