Herbaceous layer vegetation on Maryland serpentine

Herbaceous layer vegetation was distinct among the four remaining serpentine areas in Maryland according to detrended correspondence analysis. Sorensen's Indices of Similarity for importance values were 40.8-69.6% and 56.1-77.6% for composition. The Shannon-Wiener diversity index (H′) varied 1.88-2.49 and alpha diversity (total species sampled) from 23-33. Schizachyrium scoparium (Michx.) Nash dominated three sites, and Sporobolus heterolepis Gray and Schizachyrium scoparium were dominants at the fourth. Twentytwo species collectively characterized the herbaceous layer of the four sites. Preliminary observations of an incidental major fire of unknown origin at one site suggested that restoration of indigenous serpentine vegetation may require cutting of coniferous trees followed by prescribed burns to control seedlings and saplings.