Tree Ring Stable Isotopic Evidence for Climate Change in Coastal Wetlands of the Northeastern United States

Recent studies of the stable isotopic (δ ¹³C, δ ¹⁸O, δ D) composition of tree rings have provided several robust paleoenvironmental records that span several millennia. These records are exceptionally important to human populations because they resolve climatic shifts that occur on the scale of years. Reconstructing Holocene climatic conditions for the northeastern United States is crucial for understanding natural variations in regional climate and for defining the limits of what can be expected during episodes of abrupt climatic change. Annually-homogenized bulk wood δ ¹⁸O values from an 800-year old Eastern White Pine (Pinus strobus) log recovered from Hundred Acre Cove, Rhode Island, range from 20.0 to 23.8 % (V-SMOW) over the 55 year period of growth. The record of δ ¹⁸O contains two well-defined, multi-annual negative excursions that are spaced approximately 40 years apart. Isotopic results from a ~5000-year old Eastern White Pine log and a modern cedar will also be interpreted.