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Title: Iowa's oldest oaks. [Quercus alba]

Journal Article · · Proc. Iowa Acad. Sci.; (United States)
OSTI ID:5609366

Tree-ring analysis revealed 33 living white oaks (Quercus alba) in Iowa that began growing before 1700. Core of wood 4 mm in diameter, each extracted from a radius of a tree trunk were analyzed. The oldest white oak, found in northeastern Warren County, began growing about 1570 and is thus over 410 years old. A chinkapin oak (Quercus muehlenbergii) was also found which was more than 300 years old. Ring widths from the white oaks are well correlated with total precipitation for the twelve months preceding completion of ring formation in July. Reconstructions of annual (August-July) precipitation for 1680-1979, based on the tree rings, indicate that the driest annual period in Iowa was August 1799-July 1800, and that the driest decade began about 1816. Climatic information of this kind, pre-dating written weather records, can be used to augment those records and provide a longer baseline of information for use by climatologists and hydrologic planners.

Research Organization:
Oak Ridge National Lab., TN
DOE Contract Number:
W-7405-ENG-26
OSTI ID:
5609366
Journal Information:
Proc. Iowa Acad. Sci.; (United States), Vol. 90:1
Country of Publication:
United States
Language:
English