An Acer barbatum-rich Ravine Forest Community in the Virginia Coastal Plain

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.