The Effect of Variable Organic Matter On Soil Organic Carbon Composition In Southern Loblolly Pine Plantation.

Forest harvest residues and forest floor materials are significant sources of nutrients for regenerating and established forests and they are significant sources of mineral soil organic matter. Residual materials are often removed, piled, or burned after a forest harvest operation. This ongoing research is conducted to examine the effects of varying forest floor inputs on the interaction of nutrient availability and content and composition of soil organic matter in Millport, Alabama. This research was installed as a randomized complete block design with 4 replicates consisting of 3 treatments. The treatments include 1) control 2) full removal of forest floor and slash material, and 3) the forest floor doubled (added from treatment 2). The tree DBH, height, and litter fall will be measured to assess aboveground productivity. The root biomass via intact root cores will be sampled to assess belowground productivity along with monthly soil moisture and temperature. Ion-exchange membranes will be installed monthly to monitor available N, P, Ca, Mg, K, S, Mn, Cu, B, and Zn. Preliminary data will include the differences in tree volumes among treatments and monthly soil moisture, temperature, litterfall rates, and root biomass data. This research will attempt to quantify the effects of forest floor slash loading on site productivity, nutrient availability, and adding/removal on soil organic carbon 15 years after treatment. This research will also characterize the limiting factors to mineral soil organic carbon decomposition along with available nutrients, moisture, and temperature.