Three Decades of Change at Albright Grove, Tennessee

A 0.4 ha vegetation plot established in 1962 in Albright Grove, an old-growth cove forest in the Great Smoky Mountains, was resampled in 1992. A 0.6 ha plot encompassing the entire 1962 plot area was surveyed, mapped, and permanently marked in 1992. The diameter (dbh) and species of all live and dead tree stems >1.37 m tall were recorded in 10 0.04 ha contiguous plots in 1962, and in 60 0.01 ha contiguous subplots in 1992. Changes in the original 0.4 ha plot area over the 30-yr period are summarized here. The basal area of standing dead trees decreased from 15.7 to 3.5 m2/ha. Castanea dentata accounted for 29% of the original, and 0% of the recent standing dead basal area. Live tree basal area and biomass increased from 47.3 to 57.7 m2/ha, and 386 to 459 Mg/ha, respectively. Total stem density decreased from 642 to 563 stems/ha. Size-class distributions exhibited a gradual, log-linear decrease in stem density with increasing size at both sampling dates. No marked changes in species composition of the tree stratum were observed; Acer rubrum and Tsuga canadensis dominated at both sampling dates. Species-specific, radial growth rate means ranged from 0.7 to 2.2 mm/yr. Mortality rates for all canopy trees >30 cm dbh were in the 0.5 to 1.5%/yr range. Changes in the stand appeared to be driven by small canopy gap dynamics.