Climate-Growth Relationships of Eastern Hemlock and Chestnut Oak from Black Rock Forest in the Highlands of Southeastern New York

Abstract

Three eastern hemlock (Tsuga canadensis (L.) Carr.) and three chestnut oak (Quercus prinus L.) ring-width chronologies were constructed from old-and second-growth stands in the Black Rock Forest in Cornwall. New York, the first developed for the highlands of southeastern New York State. The longest hemlock chronology extends from 1780-1992 and the longest oak chronology from 1806-1994. The oldest trees sampled had minimum ages of 275 and 300 years for hemlock and chestnut oak, respectively. The tree-ring chronologies were compared to monthly temperature and precipitation data from nearby West Point, NY for the 1850s-1990s and to Palmer Drought Severity Indices for 1911-1990. The chronologies provide forest growth information for the period prior to the initiation of meteorological measurements, begun in 1824 at West Point. Black Rock Forest eastern hemlock growth correlates positively with current July and prior September precipitation, with February-March temperature and with prior September Palmer Drought Severity Indices. It correlates negatively with prior June temperature. Black Rock Forest chestnut oak growth correlates positively with current June-July and prior September and December precipitation, with January temperature, and with prior September-October and current June-July Palmer Drought Severity Indices. It correlates negatively with current June-July temperature. The Black Rock Forest tree-ring records and analyses yield useful information for climate reconstruction and for assessing the potential impact of anthropogenic change (e.g. CO₂-induced climate effects, CO₂ and N fertilization, acid deposition, changes in soil chemistry due to atmospheric pollution).