Ecological Biogeography of Rare Plant Species in the Mid-Atlantic Region
Larry E. Morse
Chief Botanist, The Nature Conservancy
The President Mr. Ohlmacher called the 2050th meeting to order at 8:18 p.m. on November 17, 1995. The Treasurer read the minutes of the 2049th meeting and they were approved. The President then did not read the minutes from the meeting held 100 years ago since they were held one less meeting per year than we currently hold.
The President introduced Larry E. Morse of The Nature Conservancy, who spoke on “Ecological Biogeography of Rare Plant Species in the Mid-Atlantic Region”.
Mr. Morse first clarified that the mid-Atlantic region did not involve a vast area of algae between North America and Europe, but rather the area accessible to Washington, DC, for a weekend trip. Although forests in this region are rich in vegetation, they are typically not the sites of rare plant species. Instead sites having unusual substrates or periodic natural disturbances are typically hosts for rare plant species. More than 100 plant species native to the mid-Atlantic region are considered globally rare. Another several hundred plant species are rare in this region but common in other parts of the world. Mr. Morse described many examples of these rare plant species. One example of a rare native plant species in forested areas in the Running Buffalo Clover which was thought possibly to be extinct as recently as 1983. Since then, the clover has been found in fifty sites from West Virginia to Missouri. Another example is the butternut tree which was once common but is becoming rare due to a deadly fungus.
Boggy areas located atop some mountains have plant species dating from the ice age. Some West Virginia valleys in mountains containing sandstone rock outcrops have similar plants within a watrershed but different plants compared to other watersheds. This condition indicates that the plants within the watershed are old species.
Combinations of common plant species can be rare. For example, a sandy area on a West Virginia mountain contains a plant species found typically in sandy lowlands, a plant species common further north, and a plant species native to the high Appalachians. Another unusual combination can be found at Ice Mountain, West Virginia and also in Alaska. The combination of a dwarf dogwood, northern bedstraw, twinflowers, and a wild rose has been found together near openings in the ground at Ice Mountain that stays about 38°F year round.
Other geological features with rare plant species include limestone, share barrens, and serpentine rock. Midwestern shooting star thrives in Pennsylvania on limestone, which is high pH. Also, stands of white cedars can be found on north facing limestone cliffs near Antietam. The shale barrens are too hot and dry for most plants, so plants there must be perennials in order to develop deep roots to tap underground water. An example is Kate's Mountain near the Greenbrier Resort. Serpentine rock contains a strange mix of chemicals that make growing difficult. A rare relative of snapdragons normally found near Cape Cod has a large stand on serpentine near Baltimore.
Mr. Morse closed the talk by entreating the audience to enjoy the woods, but not to overlook the rare plant species in the non-forested areas.
Mr. Morse then kindly responded to questions from the audience. The President thanked the speaker on behald of the Society, introduced one new member, announced the speaker for the next meeting, restated the parking policy, and adjourned the 2050th meeting at 9:32 p.m.
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