Noteworthy Collections: Maryland, Virginia, West Virginia, and Alabama
Noteworthy Collections: Maryland, Virginia, West Virginia, and Alabama
Between 1986 and 1990 a collection of vascular plants from several natural areas of National Park Service lands in the District of Columbia was conducted. These voucher specimens are deposited in the United States National Herbarium (US) at the Smithsonian Institution. Sixty-six species are new reports for the District of Columbia. They represent 33 families and 54 genera. Ten are indigenous species and 56 are introduced.
The project described in this paper is the outcome of National Park Service cooperation with the Smithsonian Institution and The Nature Conservancy. The purpose is to provide a checklist of vascular plants in the District of Columbia at the end of the twentieth century. Since the District of Columbia is not a state it has been excluded or inadequately represented in published state and county plant lists.
Conifers have spread rapidly in four protected serpentine areas in Maryland during the past 50 years. In three areas, more than 80% of grassland and savanna seral stages have succeeded to woodland and forest dominated by Pinus virginiana or this species with Juniperus virginiana. Before settlement was effected circa 1750, Native American fire hunting practices maintained vast areas of serpentine grassland and oak savanna. After settlement, livestock grazing apparently replaced Indian fires as the primary factor inhibiting woody plant succession in many areas including Soldiers Delight. Areas not grazed succeeded to forest, probably deciduous, and the regional abundance of these relatively fire-intolerant conifers probably increased substantially. Cessation of grazing and other disturbances such as logging by the mid-1900s apparently have allowed these conifers to spread rapidly in remaining serpentine openings. Although seasonal drought may slow the rate of conifer succession, extant grasslands and savannas will disappear without major perturbations such as logging and fire.
Acer barbatum Michx. (southern sugar maple) has been regarded as a potentially important component of maturing upland hardwood forests of the Gulf and southern Atlantic coastal plains. However, recent studies of upland hardwood forest composition in the Virginia Coastal Plain have encountered no stands containing this species. It does not normally occur in the usually level to rolling topography of the Virginia Coastal Plain, but rather occurs in steep-sloped ravines cut into the calcareous Pliocene marine deposits which underlie the area. A floristic reconnaissance of such a ravine system (Grove Creek watershed, James City County) in the Virginia Coastal Plain revealed that in this, as in other such calcareous ravines in the area, there occur several species which, like Acer barbatum, are at or near their northern range limits: Bumelia lycioides, Viburnum rufidulum, Berchemia scandens, Carex oxylepis, Scirpus lineatus [=S. fontinalis Harper], Uniola sessiliflora, Sphenopholis filiformis, Malaxis spicata, Ponthieva racemosa, and Fleischmannia incarnata. An even larger number are strongly disjunct from a primary range further west in Virginia: Quercus muehlenbergii, Magnolia tripetala, Cornus alternifolia, Stewartia ovata, Athyrium pycnocarpon, Carex bromoides, Aralia racemosa, Caltha palustris, Ranunculus septentrionalis, Sanicula marilandica, Thalictrum dioicum, Triosteum perfoliatum, Solidago flexicaulis, Campanula americana, Desmodium glutinosum, and Mitella diphylla). The finding of M. diphylla in this watershed was a Coastal Plain record for the southeasten [sic] states. Quantitative sampling of the woody vegetation showed that Acer barbatum had the highest basal area in the stand, but was slightly less abundant than Fagus grandifolia in the canopy and much less abundant than the latter in the understory. Acer barbatum reproduction has been episodic and local within the forest, in contrast to that of the widely reproducing F. grandifolia.
A floristic and vegetational study of the vascular plant flora of the Chauga River gorge was initiated in 1985, resulting in the collection and annotation of 568 species representing 341 genera and 107 families. Voucher specimens have been deposited in the Clemson University Herbarium (CLEMS). Plant communities described are typically dominated by oak and/or pine species. The Chauga River is part of the Savannah River drainage system located in the extreme northwestern portion of South Carolina and is one of the three major drainage systems associated with the Andrew Pickens District of the Sumter National Forest. Recently, the National Forest Service designated the Chauga River and immediate uplands as a scenic river, thereby protecting the vegetation from the impacts of timber management.