Survival and Growth of Individual Trees in Mixed Species Plantations of Bottomland Hardwoods on 2 Mississippi Delta Soil Types

Abstract

Water oak (Quercus nigra L.[Fagaceae]), Nuttall oak (Q. nuttallii Palmer), and green ash (Fraxinus pennsylvanica Marsh. [Oleaceae]) were planted in mixtures at 2 spacings, 1.8 and 2.7m (6 and 9 ft) triangular spacing, on 2 contrasting soil types: Sharkey and Dundee. Survival was high for green ash and Nuttall oak, but was poor for water oak. Green ash grew the fastest initially, but the oaks have caught up or exceeded the ash by age seven on the Dundee soil. On the Sharkey soil, Nuttall oak is nearly as tall as the ash, but the water oak is still shorter. Although green ash has been able to maintain height supremacy on each soil type, the oaks have exceeded them in crown diameter and stem diameter, and trends suggest that the oaks will soon surpass the ash. Both oak species appear to represent a viable mixture on the Dundee soil, but if growth trends continue, ash will eventually fall into inferior crown positions. Nuttall oak and green ash appear to mix well on the Sharkey soil, but most water oak will not attain codominance.