The Big Trees of Chapman Forest

Overlooking the Potomac River in Charles County, between Mount Aventine (the ancestral home of the Chapman family) and Glymont is a several hundred acre tract of old-growth, Shell-Marl Ravine Forest. In addition to its value as an old-growth community, this woodland is remarkable because its unique combination of rich, alluvial soils, steep topography, and close proximity to the Potomac River have given rise to an exceptionally rare and diverse flora and fauna.

Many of the species found in this forest community, such as basswood, Chinquapin oak, slippery elm, hophornbeam, foamflower, harbinger of spring, wild stonecrop, ginseng, and toadshade trillium, usually occur in the piedmont and mountain regions of the state and are rarely found on the coastal plain. Some of these disjunct or isolated species, namely glade fern, butternut, and cylindrically-ornate wood snail (Vertigo ventricosa), are also highly rare in Maryland or globally rare. It is also noteworthy that the state-endangered glade fern population colonizing two ravines is the largest known in Maryland.

Human disturbance of the site has been minimal, thus allowing the forest to mature and sensitive species to flourish. Steep, inaccessible ravines have prevented agriculture on the property. However, some sections were selectively logged in the past, including the recent removal of many very large tulip trees and northern red oaks, and light grazing probably occurred in areas. Despite this, the forest remains essentially unspoiled and free of pollution and invasive exotic plants (except along some logging roads and the Potomac shore.)

A diversity of magnificent trees, many near champion size, compose the canopy. Tulip tree, northern red oak, white ash, bitternut hickory, and beech are the dominant species. Well distributed trees are Chinquapin oak, slippery elm, sycamore, sweetgum, and black walnut. Occurring in smaller numbers, but widespread are white oak, basswood, hackberry, persimmon, American holly, mockernut hickory, pignut hickory, and black gum. Sassafras is abundant and reaches a very large size on sandy loam near Aventine. Black oak is common only in alluvial valleys near the Potomac and on dry, remnant gravel terraces above the river. Ancient chestnut oaks inhabit north-facing slopes near Glymont, where remnant gravel terraces descend into calcareous ravines. American basswood is the dominant tree on the rugged slopes of the Potomac shoreline along with hophornbeam and to a lesser extent northern red oak and red cedar.

The dominant understory species throughout are pawpaw and spicebush. Dogwood is well distributed, especially in alluvial valleys. Redbud is generally concentrated near Aventine and reaches a very large size on upland slopes. Bladdernut also reaches great size in one colony growing on a north-facing slope close to Aventine. Hornbeam is scattered in damp ground along streams, but is a minor component throughout.