Betula pubescens planted trees, while naturally regenerated trees seem less susceptible. This disease also affects "Betula pendula" and in 2000 was reported at many of the sites planted with birch in Scotland during the 1990s. The outer layer of bark can be stripped off the tree without killing it and can be used to make canoe skins, drinking vessels and roofing tiles. The inner bark can be used for the production of rope and for making a form of oiled paper. This bark is also rich in tannin and has been used as a brown dye and as a preservative. The bark
Alnus incana Alnus incana Alnus incana, the grey alder or speckled alder, is a species of alder with a wide range across the cooler parts of the Northern Hemisphere. It is a small- to medium-sized tree tall with smooth grey bark even in old age, its life span being a maximum of 60 to 100 years. The leaves are matte green, ovoid, long and broad. The flowers are catkins, appearing early in spring before the leaves emerge, the male catkins pendulous and long, the female catkins long and one cm broad when mature in late autumn. The seeds are small, long, and