Morphological and Nutritional Development of Three Species of Nursery-Grown Hardwood Seedlings in Tennessee

Abstract

We followed the morphological and nutritional development of three common hardwood species growing under typical cultural practices in a southern hardwood nursery. Yellow poplar was by far the largest seedling at the end of the season, followed by Nuttall oak and green ash. Seasonal periodicity of morphological development varied by species, although large increases in lateral root weight occurred in late fall for all three species. Coefficients of variation for the morphological components over time were high for all three species and most parameters. All three species had strong correlations between root collar diameter (RCD) and many other morphological parameters including number of first order lateral roots. The seasonal periodicity of nutrient concentrations, translocation and allocation were documented. No changes in soil carbon and organic matter content were found, probably as a result of the addition of mulch and leaf litterfall. In spite of similar fertilization regimes, foliar nutrient concentrations varied by species. Yellow poplar appeared to be the most efficient at withdrawing nutrients from senescent leaves while Nuttall oak had higher nutrient translocation efficiencies. Large amounts of fertilizer elements were removed by harvesting, but overall nitrogen and phosphorous balance (applied fertilizer minus removed) was positive. Nitrogen use efficiency was relatively high for all species. Yellow poplar had the highest nitrogen removal efficiency and biomass productivity, indicating higher use of fertilizer materials.