Black ash (Fraxinus nigra Marsh.) forests of north-central North America are currently threatened by the non-native emerald ash borer (Agrilus planipennis, EAB). Despite the wide distribution of F. nigra ecosystems, and the concern over EAB impact, little is known about their structure and natural stand dynamics. We sampled six old-growth F. nigra stands to assess structure, composition, tree recruitment, and past disturbance. Dendrochronological results revealed that disturbance rates fluctuated markedly over the past 200 years or more, but remained relatively low, suggesting small- to moderate-scale disturbances. Recruitment age structures revealed that (i) F. nigra is able to maintain long-term dominance through...
