• A Technique for Examining Non-Climatic Variation in Widths of Annual Tree Rings with Special Reference to Air Pollution

      Nash, Thomas H., III; Department of Botony and Microbiology, Arizona State University; Laboratory of Tree-Ring Research, University of Arizona (Tree-Ring Society, 1975)
      A new technique is developed for examining non-climatic variations in widths of annual tree rings. For each tree core, the technique involves making an adjustment for regional climate as inferred from a regional chronology based on surrounding sites. The technique is applied to two stands in Gila County, Arizona, where air pollution is potentially a limiting factor on tree-ring growth. For the stand closer to the pollution sources, a marked decrease in tree-ring widths minus climate is evident during the period 1908 to 1920. Although this decrease coincides with a period when two smelters were operating nearby, air pollution cannot be definitively identified as the cause of the decrease in ring widths.
    • Tree-Ring Research in the Netherlands

      Eckstein, D.; Brongers, J. A.; Bauch, J.; Institute for Wood Biology, University of Hamburg; State Service for Archaeological Investigations, Amersfoort, the Netherlands; Institute for Wood Biology, University of Hamburg (Tree-Ring Society, 1975)
      Two independent local tree-ring chronologies of oak in the Netherlands are described. Chronology I contains recent wood, wood from mills, and paintings. This chronology begins in A.D. 1973 and goes back to 1385 and is thought to be from inland areas of the Netherlands and the adjacent German area. Chronology 11 is built up from paintings and sculptures and ranges from A.D. 1623 to 1140; the origin of the wood is presumed to be from a coastal site in the Netherlands.