Fungal disease and a deadly type of beetle may be all it takes to drive Britain's ash trees to extinction, a new study has found.
Researcher Peter Thomas from Keele University surveyed the biology and ecology of the trees and found it to have a very bleak future.
The study was published Tuesday in the Journal of Ecology.
Ash (Fraxinus excelsior) can be found naturally in a majority of the British Isles. Such a tree is a vital species in towns and cities and is the second most commonly existing tree in woodlands.
Ash is the most common species alongside hedges and its length is said to comprise nearly 100,000 kilometers in Great Britain.
Beating The Drought-Tolerant Ash
Ash is one of the species that thrive amid the ongoing global warming. Nitrogen has even acted as a fertilizer and climate change has even helped the trees, thanks to its drought-tolerant feature. With this, the trees are able to cope even if there is less rainfall. In fact, it thrives better in warmer springs as it is sensitive to spring frost.
Despite its strong stance amid the booming global warming, ash succumbs to two things: a fungal disease called ash dieback and a deadly green beetle called emerald ash borer.
The effects of these dangerous factors are said to be so vast that Thomas said its invasion may wipe out all ash trees in Europe just like elm in the Dutch elm disease.
Ash Dieback
Ash dieback causes leaves, branches and subsequently the entire tree to die. The disease is caused by a fungus known as Hymenoscyphus fraxineus. It was first noted in 1992 and 2012 in Europe and in Britain respectively.
Today, the disease is said to affect over two million square kilometers from Scandinavia to Italy. In worst-case scenario estimates, ash dieback may cause 95 percent of ash trees in Britain to die.
Recent studies suggest that some clones of ash trees are resistant to ash dieback, giving hope to the success of breeding projects. However, even if these programs are successful at keeping ash dieback at bay, it cannot protect the trees against another potentially deadly cause of ash extinction - the emerald ash borer.
Emerald Ash Borer
Emerald ash borer or Agrilus planipennis originates from Asia, just like ash dieback. The deadly beetle was first introduced to North America in 2002 by accident. With its first arrival, millions of ash trees already died.
In 2003, the emerald ash borer was seen in Moscow and has now spread to the west, even possibly reaching Sweden.
Although the adult insect only feed on the leaves and cause subtle damage, the larvae burrowed underneath the bark and wood may kill the entire tree.
"Our European ash is very susceptible to the beetle," says Thomas. He adds that it is only a matter of time before it expands across Europe including Britain. With this, the deadly beetle may become the biggest hazard that ash trees in Europe may ever face — far more crucial than the ash dieback.
Effects Of Ash Loss
Losing ash trees may take a toll on the biodiversity and countryside of Britain. Over 1,000 species of different organisms such as 55 mammals, 78 vascular plants, 68 fungi and 548 lichens among others are associated with ash trees. Most of these species are already either endangered or threatened and with the impending situation of ash trees, these species may really become locally extinct.
Although these species may still turn to other trees such as alder, lime and rowan, the landscape of the British countryside will never be the same without the ash trees.
Uses Of Ash Tree
Ash is famously known for making up about 10 percent of coppiced wood used in building the Sweet Track, a 6,000-year-old wooden walkway across the Somerset Levels.
Ash was also used in making boat frames, tenon pegs and musical instruments, specifically guitars.
Ash also has contribution to cattle as ash foliage was used as fodder for sheep and goats.
Humans also used to take ash keys or fruits and pickled it with vinegar. A sweet exudate from the bark called manna was also used as a sweetener and mild laxative.
Ash has also been proved useful even in the time of Hippocrates when its leaves and bark were used to treat diarrhea, gout, rheumatism and gallstones, among others.
