Composition, Biomass, and Age Distribution of an Old-Growth Mixed Mesophytic Stand in the Boston Mountains of Northwestern Arkansas

by

James A. Crawshaw, David W. Stahle, and Don C. Bragg

Environmental Specialist (JAC), Missouri Department of Natural Resources, Jefferson City, MO; Distinguished Professor (DWS), Department of Geosciences, University of Arkansas, Fayetteville, AR; Research Forester (DCB), USDA Forest Service, Southern Research Station, Monticello, AR; JAC is corresponding author. To contact, call 573-751-2034 or email james.crawshaw@dnr.mo.gov.

Abstract – The rugged topography of the Boston Mountains shelters numerous stands of relatively unstudied mixed mesophytic forest, some of which are old-growth. The objective of this study was to document the composition, biomass, and age distribution of a small example of such an old-growth mixed mesophytic stand along the base of a northeast-facing bluff in the Upper Buffalo Wilderness Area of Newton County, Arkansas. This stand contained 21 different tree species ≥10 cm in diameter, with none dominant-together, American basswood (Tilia americana), cucumbertree magnolia (Magnolia acuminata), sugar maple (Acer saccharum), blackgum (Nyssa sylvatica), and American beech (Fagus grandifolia) combined for just over 68% of total stand basal area. These five species also contributed nearly 55% of the 261.6 Mg/ha of total live tree (oven-dry) biomass of this stand. Tree-ring dating of increment cores indicated that some blackgum exceeded 400 years of age, and numerous American beech, American basswood, shagbark hickory (Carya ovata), black hickory (Carya texana), and sugar maple exceeded 140 years. According to the tree-ring record, there were no obvious periods of stand-level release in this uneven-aged stand. This stand has higher basal area, biomass, and tree species richness than other types of old-growth forest in the Boston Mountains, but less than that often seen in mature, mixed mesophytic forests of the Appalachian Mountains.