Composition and diversity of ground-layer vegetation in silvicultural openings of southern Indiana forests

Between 1993 and 1995 we sampled ground-layer vegetation on 150 plots in Fa cus-Acer saccharum/Arisaema Mesic Slope and Quercus alba-Acer saccharum/Par thenocissus Dry-Mesic Slope forests to determine how the understory of thes e forests responded to forest management. Four different stand types, clear -cuts (2-12 ha), group-selection openings (0.1-1.6 ha), single-tree selecti on openings (0.005-0.013 ha) and uncut 80-100 y-old reference stands were s ampled. There was little relationship between the percent cover of most eco logical species groups and opening age or size on either mesic or dry-mesic slopes. While clear-cuts and group-selection openings had significantly gr eater cover of several ecological species groups (used to classify mesic an d dry-mesic slopes) than reference stands, single-tree selection openings d id not differ significantly from reference stands in the cover of any ecolo gical species group. Pearson correlation analysis indicated that more groun d-layer species were significantly correlated with opening size than openin g age, suggesting that the size of the initial opening has more influence o n species composition than opening age. Overall, forest management has not constituted a severe enough disturbance to shift ground-layer species compo sition away from that associated with the sampled ecological landtype phase s (mesic and dry-mesic slopes). Aspect was the dominant factor determining species distribution in Canonical Correspondence Analysis ordinations of gr ound-layer vegetation in both openings and reference stands.