ALB-Historic England-Developing the dendrochronology of elm in historic buildings (360G-cabinetoffice-GA-169002)

Elm is, after oak, the second most frequently found timber in historic buildings. Over the last few decades the dendrochronological dating of oak has become well established, with the dating of well over two-and-a-half thousand building phases now having been derived from tree-ring series. Elm is known to be more difficult to date, generally having fewer rings, even in relatively large timbers, and less even growth. It is generally more prone to insect degradation too. The complex genetic mix of elms has often led to it being described as the most variable tree amongst native species. Although often encountered, dendrochronologists have tended to shy away from attempting to date it therefore, not only because of these factors, but also as result of economic pressures, in that lower chances of success tend to mean that scarce resources are often directed elsewhere, rather than being put into an activity that is perceived to have a lower chance of a return. There have however been a few successes in the past, with elm being dated against oak sequences in the same structure, and in the case of an Essex farmhouse investigated in 2015, producing a site chronology that could be dated against oak chronologies with levels of agreement typically seen amongst oak chronologies themselves. In a similar way to the early development of oak dating in historic buildings, this project will adopt a targeted approach, identifying buildings in a selection of geographical areas that have the best potential for dating in terms of numbers of rings present, numbers of timbers available, and possibly also the presence of datable oak for direct growth comparison, therefore maximising the chances of success in building elm chronologies that may then be used as the springboard to a greater exploitation of elm dendrochronology in the future.