Flora of Araby Bog, Charles County, Maryland.

By Roderick Simmons, Maryland Native Plant Society, Botany Committee Chair; flora surveys by Roderick Simmons and Mark Strong

The Araby Bog is a diverse, 50 acre "Magnolia Bog" with a large, open, sphagnous section that gives rise to pristine perennial streams that flow into adjacent Maftawoman Creek. Magnolia Bogs are acidic wetland seeps associated with gravel terraces of the inner Coastal Plain near the Fall Line that are named for the predominance of Magnolia virginiana in the canopy. They are different geologically and hydrologically from the famous peat bogs of New England and northern Europe because they occur in terrace gravel deposits and are spring-fed wetlands. Magnolia Bogs are actually seeps or springs that form where a perched water table (especially common in terrace gravel formations which hold large amounts of rainwater in the porous gravel and sand lenses) intersects the ground surface above a clay lens or aquiclude. The soils of gravel terraces are weathered, very acidic (pH TO), and nutrient deficient as a result of Calcium ions and other nutrients associated with rich soils leaching into stream valleys below over long periods of time. The soils of Magnolia Bogs are also very acidic, sandy, and gravelly because they are derived from terrace gravel soils. 'they also are not characterized by accumulated peat or organic soils, except in some super-saturated areas, because they form on spring-fed, gravel-sand substrates.

Magnolia Bogs have become increasingly rare and surviving ones degraded in the Washington metro area, the heart of their range, because of extensive development of the gravel terraces that surround the bogs, thereby destroying or severely depleting their water supply. Most of the famous ones surveyed by the Smithsonian Institution and others nearly a century ago, like the Powder Mill Bogs, Holmead Swamp, and Terra Cotta Bog, have been destroyed. Some, like the Suitland Bog and the Oxon Run Bogs, have survived, although the Suitland Bog is greatly disturbed and faces further damage by encroaching development. The Little Paint Branch Bogs (collectively called the 1-95 Bog by the Maryland Natural Heritage Program), small remnants of the once-extensive Powder Mill Bogs, exist under power lines and are therefore degraded by utility maintenance, especially herbicides and utility vehicles, as well as invasive exotic plants. The Franconia Bog in Springfield, Virginia is probably Fairfax County's largest and beat remaining Magnolia Bog, but is sadly mostly destroyed by constant channelized stormwater runoff from a recent development placed too near. Urbanization, stormwater runoff, utility maintenance, and invasive exotic plants have degraded most, if not all, of the remaining bogs. to contrast, the Araby Bog is perhaps unique in the region because of its very large size and pristine, undisturbed condition. Unfortunately, it is currently threatened by the proposed Falcon Ridge and Hunters Brook development projects because of the extensive clearing, re-grading and construction proposed for the land surrounding the bog, especially the groundwater recharge areas for the bog.

Magnolia Bogs are globally rare natural communities; however, the prospect for their future survival is not good. Unless adequate protection is given to these sites, most of them will disappear in the decades to come. To ensure some degree of conservation and stewardship, as well as recognition of their being highly rare natural communities, it is strongly recommended that all Magnolia Bogs, regardless of me species content, be designated a "Wetlands of Special State Concern" status.

The following is a list of characteristic Magnolia Bog species of the southern Maryland region that occur in the Araby Bog. Species actively tracked by the Maryland Natural Heritage Program (noted below) have a state rank of S1 (highly state rare) or S2 (state rare) and sometimes a state status of E (endangered) or T (threatened). A watchlist species has a state rank of S3 and is rare to uncommon, but is not actively tracked: