An assessment of pitch pine (Pinusrigida) health and mortality in southern Ohio

Abstract

The status of pitch pine (Pinusrigida Mill.) health and mortality and relationships between pitch pine vigor or mortality and potential causal factors were studied in natural stands in southern Ohio, and less intensively in northeastern Kentucky, southern Pennsylvania, eastern West Virginia, and the Thousand Islands region of southern Ontario, Canada. High pitch pine mortality was largely confined to the Thousand Islands and ridgetop southern Ohio stands. Mortality was not explained by endogenous site factors on southern Ohio ridgetop sites. Ohio trees with decreased vigor (sparse crowns) also typically exhibited the following: (i) stunted needles; (ii) chlorotic needle mottling that was indistinguishable from O3 and SO2 symptoms induced in laboratory fumigations; (iii) lower total foliar mass; and (iv) higher rates of mortality. The cause(s) of mortality and declining vigor within southern Ohio pitch pine populations remains largely unexplained, but was not associated with pathogens in the bole or main roots, or bark beetle infestation. The possibility that air pollution is acting upon sensitive portions of the Ohio population cannot be ruled out.