Structural and compositional dynamics of a near-natural temperate deciduous forest in the central United States1

Abstract

Abstract Pioneer Mothers' Memorial Forest is a unique largely undisturbed, mixed mesophytic hardwood forest in south-central Indiana, USA. We report on 26 years of change in community composition and structure; plots were previously sampled in 1978 and 1989. In 2004, we re-measured trees ≥ 5 cm in diameter for 153 permanent plots, as well as downed woody debris, and standing dead trees. In 1978, density was 718 stems ha−1 and basal area 26.2 m2 ha−1, but by 2004 density had decreased to 493 stems ha−1 with an increase in basal area to 31.4 m2 ha−1. Large density decreases were attributed to Acer saccharum, Sassafras albidum, Juniperus virginiana, and Cornus florida mortality, while basal area increased largely because of Liriodendron tulipifera and A. saccharum growth. The stand exhibited a reverse-J diameter distribution, but density in the lower diameter classes, < 15 cm, greatly decreased over time. The overstory (trees ≥ 25 cm) was dominated by A. saccharum, L. tulipifera, Quercus spp., and Fagus gran...