DENDROECOLOGICAL ANALYSIS OF SUCCESSIONAL DYNAMICS FOR A PRESETTLEMENT-ORIGIN WHITE-PINE MIXED-OAK FOREST IN THE SOUTHERN APPALACHIANS, USA

1 Prior to European settlement, Quercus alba, Castanea dentata, Carya spp. and Pinus strobus dominated Ridge and Valley forests in southern West Virginia. Dendroecological techniques were used to study the disturbance history and successional dynamics of one of the few remaining valley-floor remnants of this primary forest type. 2 The uneven-aged forest is presently dominated by P. strobus, Acer rubrum, Q. alba, Q. rubra and Q. velutina. Quercus alba and P. strobus represented most of the oldest and largest trees in the forest, while Acer, Fagus and Tsuga were the youngest and smallest. Maximum age was 295 years for Q. alba and 231 years for P. strobus. 3 There was continuous recruitment of Q. alba trees from 1700 to 1990. The abundance of P. strobus increased between 1830 and 1900, with a peak in the 1870s associated with releases in radial growth. The subsequent peak recruitment of Q. rubra and Q. velutina from 1880 to 1900 is suggestive of possible facilitation of these species by P. strobus. Following the cessation of Pinus and Quercus recruitment in 1900, Acer, Fagus and Tsuga abundance increased, particularly A. rubrum. 4 Radial growth chronologies across all species and age classes exhibited a series of major or moderate releases at regular intervals (typically every 20-30 years). However, the asynchronous nature of these releases suggests that they were caused by a series of small-scale disturbances, such as fire and wind-throw, each of which had localized impacts within the stand. 5 We believe that Pinus and Quercus were maintained in this stand during the 18th and 19th centuries by periodic disturbance, in particular fire, which would have eliminated later successional species. The lack of Pinus and Quercus recruitment after 1900 and the subsequent increase in Acer, Fagus and Tsuga indicates the transitional nature of this forest in the absence of fire. 6 Coupling of tree-ring chronologies and species establishment dates greatly increased our understanding of the disturbance history and dynamics of this old-growth forest, and we believe this represents an important approach to the study of species life-history attributes and ecological history in general.