Pine decline is a relatively new forest health issue in the southeastern
On the Fort Benning Military Reserve in
Results/Conclusions
Foliar macronutrient concentrations were sufficient or nearly sufficient, and did not differ by symptomology or age. Concentrations of N, P, K, Ca, and Mg in the last flush of 2006 averaged 0.81, 0.08, 0.45, 0.24, 0.09%, respectively. Similar results were found for most foliar micronutrients (i.e., B, Cu, Fe, Zn). Foliar and root Mn concentrations were 28% and 58% less on the S plots compared to the A plots. Symptomologies differed regarding relationships between tissue Mn concentration and both Ca and Mg concentrations. On the A plots, for example, Mn concentration explained 50% of the variation associated with the Ca concentration of the last flush of 2006, but on the S plots, the relationship between foliar Mn and Ca was not significant. Our assessment of mineral nutrient concentrations indicates that one component of pine decline may be interference of Mn with the function of Ca and Mg. Together with tree growth, root disease, and site quality data, this information will be used to hypothesize the central cause of pine decline at Fort Benning Military Reserve, and provide insight to its origin elsewhere in the southeastern United States.