Contrasting the Effects of Organic Matter Removal and Soil Compaction on Root Biomass of 9-year-old Red Oak, White Oak, and Shortleaf Pine in a Missouri Ozark Forest

—Nine-year old artifi cially regenerated red oak (Quercus rubra L.), white oak (Q. alba L.), and shortleaf pine (Pinus echinata Mill.) trees were excavated from plot borders of a U.S. Forest Service long-term soil productivity study in the Carr Creek State Forest near Ellington, MO, to quantify treatment eff ects on aboveand belowground tree biomass. Th e study consists of factorial combinations of soil compaction and organic matter removal treatments that are replicated three times. Seventy-two trees were removed from treatments containing two levels each of soil compaction (SC) and organic matter removal (OMR) with weed control (WC) and without weed control (NWC). Except for red oak, neither SC nor OMR alone aff ected root or shoot biomass production (weights) for trees in the study. However, biomass for both root and shoot were aff ected by interactions between SC and OMR with and without weed control. Regardless of the SC or OMR treatments, root biomass was higher with WC than NWC. Only the root:shoot ratio of red oak was aff ected by treatments, where it was higher for trees in the severe SC treatment than for trees in the no soil compaction treatment. Overall, measurements of aboveand belowground biomass on plot border trees indicate that after nine growing seasons, site productivity has been aff ected more by the WC treatment than by SC or OMR. 1Research Soil Scientist, U.S. Forest Service, Northern Research Station, 208 Foster Hall, Lincoln University, Jeff erson City, MO 65102. To contact, call (573) 681-5575 or email at [email protected].