Center for Tree-Ring Science

Sixty years of research and countless study sites later, the Center now houses over 10,000 cross-sections (slabs) of wood! These specimens are systematically boxed and archived, often referred to again later for new educational or research purposes. In some cases, if the wood is thousands of years old, it is vacuumed sealed and stored in deep freezers.

Recent work dating longleaf pines from the Congaree National Park in South Carolina showed not only fire scars but also turpentining scars! Turpentining scars reflect the industry of naval stores, or the chemical compounds produced from pine trees. Resin was collected by making chevron cuts move up the tree throughout the growing season, later to be distilled into turpentine, tar, rosin, and pitch. This work was done by enslaved laborers and later, freed workers, until the 1940’s when much of the pine forests were depleted, the naval industry moved into steel production, and pine compounds were produced synthetically.

From the CTRS archives: This is a bur oak cross section that grew along a creek in northern Missouri 3950 years ago. It has 190 tree rings which provide a valuable record of yearly climate information from the time when it was growing. Environmental conditions such as historical droughts and late spring frosts are preserved in these rings. Oak wood is typically brown, but turns black over thousands of years when buried in waterlogged conditions with little oxygen.

Have you ever seen wood that carousels up a tree? There is a lot of speculation on why trees form a spiral grain from prevailing winds, to nutrient uptake, the Coriolis effect, or old age. It is often seen on snags that have lost their bark, and across many tree species. Pictured is a red pine in New York and the top and side view of a Missouri cedar, both displaying spiraling grain.

Recent fieldwork in Texas Hill Country! Working with Wildland Fire Management Specialist, Mike Lloyd, from the Texas Parks and Wildlife, CTRS conducted data collection for tree species, fire history, and cedar history of the Post Oak Ridge State Park. Soon to be opened to the public, this unique forest ecosystem spans over 3,000 acres and dotting the landscape are remnants of 100+ year old axed cedar stumps from the elusive laborers of the time known as the cedar choppers. We are grateful for the opportunity to be a part of the careful planning and research of this magnificent site!