"The terms and their definitions were collected from publications and by utilising the Internet. Forestry experts were also consulted to provide their input in the case of some of the compiled terms. The terms were taken directly from the identified sources. For some terms more than one source are mentioned. This means that the same definition was found within several literature sources without necessarily indicating the most likely original source of that definition. The listing of several sources referring to the same definition was thought to emphasise that a particular definition is more commonly used in scientific literature."