DENDROCHEMICAL RESPONSE TO SOIL LIMING IN SCARLET OAK

To test the hypothesis that the chemical element content of tree rings can record historical chemical changes in soil, wood cores were extra cted in 1989 from 65-year-old scarlet oak (Quercus coccinea Muenchh.) trees located in Moshannon State Forest in central Pennsylvania where soil chemistry had been altered by soil liming. Four wood cores were e xtracted 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 112 0 kg/ha of Ca as hydrated lime in 1963 and a repeated application on o ne-half of the plot in 1964. Wood cores were chemically analyzed for 1 5 elements, using inductively coupled plasma emission spectroscopy. Mn concentrations in tree rings on the limed plot were significantly red uced for up to 16 years following liming. Sr concentrations in tree ri ngs on the limed plot were significantly lower for up to 21 years afte r liming and up to 10 years before liming. Cu, B, and Pb concentration s were significantly lower on the limed plot in nearly all tree-ring s egments. Ca/Al ratios in tree rings were significantly increased for u p to 11 years after treatment, but Mg/Al ratios were unaffected. Resul ts suggest that changes in Mn, Sr, and Ca/Al ratios in scarlet oak tre e rings can be used to trace soil changes due to liming, but sapwood c onduction obscures the exact year of treatment effect.