Chapman Forest On the Potomac, near the Nation's Capital — expansive, unspoiled nature and history —

The single greatest feature of Chapman Forest is the large expanses of unbroken forest – extremely unusual for anywhere in the Baltimore-Washington region. Conservation biologists talk of the importance of large blocks of unbroken forest because of the habitat that it provides for a great variety of species of plants and animals that cannot grow strong communities in small patches of woods. Every intrusion made in such a block of contiguous forest creates more forest edge, and reduces the security of the species that need forest interior.

But it is not only animals. People, too, have a great need for nature. The experience of being deep in the forest, far from roads and crowds, experiencing the different sounds, sights and smells of being deep in the forest, cannot be reproduced. This experience is getting ever harder to find. We are very lucky that it is still available to us. It would be cruel and irresponsible to take it away from our children and from future generations.

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.

Deep ravines formed over millennia have cut into ancient shell-marl deposits buried well below the surface. These shells provide a calcareous soil much like limestone, and together with glauconite ( a nutrient rich, marine sediment deposited with the shells) create a highly fertile, circumneutral soil. The ravines are deepest near Glymont. Gradually the land becomes gently rolling towards Aventine. Here ancient deposits of marine sand produce a deep, sandy loam.

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.

Shell-Marl Ravine Forests are not common anywhere in the mid-Atlantic region. However, unspoiled, old-growth sites like this are highly rare. In assessing natural communities and ecosystems in need of protection, the Virginia Dept. of Natural Heritage (Conservation and Recreation) listed the state's few remaining Shell-Marl Ravine Forests (near Williamsburg) as conservation priorities.  The Chapman's site equally qualifies as a conservation priority, especially considering its closeness to Washington, D.C. and its importance in preserving the Potomac shoreline. It is perhaps Maryland's best remaining example of this rare forest community.

• Above trees represent the largest circumference of each species, but there are many of each that come close in size to the largest.
• CBH is the circumference in feet of the tree at breast height (4 1/2 feet above ground).
• The estimated age of the above trees is 180 - 200 years, according to several criteria, including growth rings of several stumps.  Some are probably older.

Thanks to Rod Simmons, Maryland Native Plant Society, and Jim Long for their information, photos, and words on this page.