Lethal Leaves
In the last couple of decades, a fungal disease called Ash Dieback has been killing Europe’s ash trees. The Forestry Commission in Britain has turned to a high-tech solution to keep the disease in check. They have developed an app so the general public can help monitor the spread of the fungus.
Ash Dieback is caused by the fungus Hymenoscyphus pseudoalbidus, which was first described in 2006. However, it is believed the infection started in 1992 in Poland, having since spread across Europe. The fungus attacks living ash trees. The origin of the fungus is unknown, though scientists think it could have come from Asia since the ash trees in Asia are immune to it.
The fungus has been shown to attack a number of ash species: the European ash, the Narrow-leafed ash and Manna ash as well as North American species such as the Black ash and Green ash. Infection first appears as dark spots on leaves and branches. Over time the fungus causes leaf loss and eventual death. Forestry commissions take the disease seriously because of its potential to ravage forests. In Denmark the fungus has destroyed between 60 to 90% of ash trees.
Ash trees are very important to the local ecosystem. Their large root systems help to stabilize the banks of rivers and streams. The trees also provide a home for a number of insect and bird species. An article by Marco Pautasso et al states that the full number of species which depend on ash trees is not completely known. However, they say that certain species of fungus are definitely specific to the ash. These species may provide food for other species so the loss of ash trees could have a wider impact on European ecology.
Given the threat of this disease, it is understandable why the UK Forestry Commission wants to stem the spread of the disease. The app is a good weapon in this fight.
“Our Tree Alert app and on-line reporting form are proving an effective tool for monitoring suspected cases of Chalara ash dieback and, now, other pests and diseases of trees in Great Britain,” said a Forestry Commission spokesperson.
“It enables us to engage a larger number of ‘eyes and ears’ around Britain to report possible cases to us than if we relied on professional surveyors alone. It also gives the public an opportunity to feel personally involved in helping to protect Britain’s trees, woods, forests and natural heritage. We are continuing to develop Tree Alert in the light of experience to maximise the quality of the reports sent to us.”
Original article by Ryan Scott – Sydney, Australia. Text edited by The Word’s methodology team