Dendrochemical response to soil liming in scarlet oak

Abstract

To test the hypothesis that the chemical element content of tree rings can record historical chemical changes in soil, wood cores were extracted in 1989 from 65-year-old scarlet oak (Quercuscoccinea Muenchh.) trees located in Moshannon State Forest in central Pennsylvania where soil chemistry had been altered by soil liming. Four wood cores were extracted and composited in 5- to 10-year increments from each of five trees on an untreated control plot and on a plot that had received 1120 kg/ha of Ca as hydrated lime in 1963 and a repeated application on one-half of the plot in 1964. Wood cores were chemically analyzed for 15 elements, using inductively coupled plasma emission spectroscopy. Mn concentrations in tree rings on the limed plot were significantly reduced for up to 16 years following liming. Sr concentrations in tree rings on the limed plot were significantly lower for up to 21 years after liming and up to 10 years before liming. Cu, B, and Pb concentrations were significantly lower on the limed plot in nearly all tree-ring segments. Ca/Al ratios in tree rings were significantly increased for up to 11 years after treatment, but Mg/Al ratios were unaffected. Results suggest that changes in Mn, Sr, and Ca/Al ratios in scarlet oak tree rings can be used to trace soil changes due to liming, but sapwood conduction obscures the exact year of treatment effect.