Composition, structure, and disturbance history of Crabtree Woods: an old-growth forest of western Maryland'

MCCARTHY, B. C. AND D. R. BAILEY. (Department of Environmental & Plant Biology, Ohio University, Athens, OH 45701-2979). Composition, structure, and disturbance history of Crabtree Woods: an old-growth forest of western Maryland. Bull. Torrey Bot. Club 123: 350-365. 1996.-Crabtree Woods is an old stand of mixed Appalachian hardwoods which has been identified as one of the finest examples of this vegetation type in Maryland. Because few botanical studies have been conducted on the Allegheny Plateau of Maryland and because the old-growth nature of this stand is unique in its present landscape, we undertook this study to describe the composition, structure, and disturbance history of the stand. A one hectare permanent plot was established in which all trees, saplings, snags, and logs were quantified. Woody seedlings and herbs were subsampled from 25 quadrats to describe the understory. Increment cores were obtained from all Quercus rubra trees within the plot and used for dendroecological analysis. The stand shows many structural and compositional features characteristic of old-growth forest. The overstory was dominated by Acer saccharum, Q. rubra, and Tilia americana. The stand exhibited a reverse-J diameter distribution typical of old forests and a number of trees were observed to have a diameter >100 cm DBH. Acer saccharum and Hamamelis virginiana were the prominent understory constituents. Quercus rubra was essentially absent from seedling and sapling size classes and does not appear to be regenerating. Logs and snags were abundant and occurred in a variety of decay states and diameter classes. Thirty-nine species of herbs were discovered, with Dicentra canadensis, Urtica dioica, and Impatiens pallida being the most abundant. Stem increment analysis shows multiple periods of recruitment likely associated with gap dynamics. However, certain synchronous releases suggest possible light anthropogenic disturbance (e.g., selective cutting or chestnut salvage).