Bonn Several sycamore trees in Bonn are affected by sooty bark disease. The fungal disease causes the trees to die off and the spores can also cause allergic reactions in humans. The city wants to fell the affected trees.
Several sycamore trees in Bonn are affected by sooty bark disease. The fungal disease causes the trees to die off and the spores can cause allergic reactions in humans. The Bonn administration will hold a press conference on Thursday to give information on the exact extent of the disease. In other cities, many trees have had to be felled using elaborate safety measures.
Sooty bark disease is caused by the cryptostroma corticale fungus, which originates from North America. It was first detected in Germany in Baden-Württemberg in 2005. The fungus actually lives endophytically, that is inside the plant and is classed as a secondary parasite, whose infestation does not usually cause any symptoms in healthy host trees, said the Julius-Kühn Institute. Experts say the fungus is now occurring so often because of the extremely dry and hot summer of 2018, which weakened the trees. Black spots form on affected trees – as if soot were escaping. The wood becomes brittle and the trees die back within a few weeks. This can cause branches to break off or even whole trees to topple over.
The fungal spores are also dangerous to humans: if inhaled, they can cause an allergic inflammation of the pulmonary alveoli. This results in a dry cough, fever, shortness of breath and shivering. The symptoms can appear within six to eight hours of contact with the spores and can last several hours, or in some cases even days or weeks. Workers must therefore wear protective suits when felling.
Original text: Nicolas Ottersbach