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Sac & Story county IA | I have noticed the difference in size of tree rings. I know there was a professor here, at Iowa State, that studied them and tried to find similarities to lunar cycles and such. Several years ago, he had the 18.6 year cycle and 89 year cycle were to converge about now. He retired and doesn't write anymore. We have had pretty good crop weather, nothing like the 1930's dust bowl. | |
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old swamp oak rings
