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Beech bark disease is a disease that causes mortality and defects in beech trees in the eastern United States, Canada and Europe. [ 1 ] [ 2 ] [ 3 ] In North America , the disease occurs after extensive bark invasion by Xylococculus betulae and the beech scale insect , Cryptococcus fagisuga . [ 4 ]
It is caused by phytoplasmas which infect the phloem (inner bark) of the tree. [2] Similar phytoplasmas, also known confusingly as 'Elm yellows', also occur in Europe. [3] Infection and death of the phloem effectively girdles the tree and stops the flow of water and nutrients. The disease affects both wild-growing and cultivated trees.
The disease can infect trees as young as 6 years-old, and infects trees throughout their lifespan. [2] Diagnostic symptoms include crown yellowing and thinning, a distress crop of cones, red brown stained outer heartwood, and laminate decay (decay that separates along annual rings).
Early stages of the disease show a light brown and tan color that looks dry and dusty. Later on, as the pathogen goes through the sexual stage, the bark will turn to a dark grey color. The bark becomes brittle and flakes off, [2] and black and grey cankers will appear. [1] These changes are symptoms, indications of a disease.
The UK Forestry Commission noted that eradication of the disease would not be possible, and instead adopted a strategy of containing the disease to reduce its spread. [10] Symptoms of the disease on larch trees include dieback of the tree's crown and branches, and a distinctive yellowing or ginger colour beneath the bark. [10]
Trees have natural chemicals that keep most fungi at bay, but climate change could be making trees more vulnerable, researcher says. Citizen scientists to study this tree disease found in ...
Maple bark disease, or maple bark stripper’s disease, is an uncommon condition caused by exposure to the spores of C. corticale. [5] The spores are hyper-allergenic and cause a hypersensitivity pneumonitis. [6] [7] The disease has been found among workers in the paper industry employed to debark, cut and chip maple logs. The symptoms include ...
Trees die within a few weeks after the symptoms first appear. Usually scattered individuals or small groups of trees are killed, but areas several hectares in size may be affected. The disease is spread from tree to tree through root grafts and over larger distances by sap-feeding beetles ( Nitidulidae ) and the small oak bark beetle.