Influence of selection harvesting and clearcutting on soil solution chemistry at the Missouri Ozark Forest Ecosystem Project

by

Alexander W. Taylor, Keith W. Goyne, John M. Kabrick, Gurbir Singh

Graduate Research Assistant (AWT), Department of Soil, Environmental and Atmospheric Sciences, 302 ABNR Building, University of Missouri, Columbia, MO 65211; Associate Professor (KWG), Department of Soil, Environmental and Atmospheric Sciences, 302 ABNR Building, University of Missouri, Columbia, MO 65211; Research Forester (JMK), US Forest Service, Northern Research Station, 202 ABNR Bldg., Columbia, MO 65211; Graduate Research Assistant (GS), Department of Forestry, Southern Illinois University � Carbondale, Carbondale, IL, 62901. AWT is corresponding author. To contact, call 434-981-9296 or email awtkvf@mail.missouri.edu.

Abstract – AbstractTimber harvesting has the potential to decrease forest nutrient capital due to elevated leaching losses from the root zone after harvest. The objective of this study was to evaluate changes in soil solution chemistry in low and medium nutrient status soils following single-tree selection and clearcut harvests at the Missouri Ozark Ecosystem Project (MOFEP). To capture soil solution dynamics before and after harvest, solution chemistry has been monitored at 18 solution sampling pits located within the nine MOFEP treatment sites from 2010 (11 to 19 months pre-harvest) to present. At each site, throughfall was collected with a trough-style collectors and soil solution was captured at 15 cm and 40 cm depths using zero-tension lysimeters. Soil nutrient flux was monitored at 15 and 40 cm depths using ion exchange resin samplers. The resultant lysimeter-derived soil solution samples were analyzed for: AlT; Ca2+; Mg2+; K+; Na+; F-; Br-; Cl-; NO2-; NO3-; SO42-, PO43-; non-purgeable organic carbon (NPOC); total nitrogen (TN); and ammonium (NH4+). The ion exchange resin samples were analyzed for AlT, Ca2+; Mg2+; Na+ and. NO3-. Preliminary statistical analysis of the data show significantly (p<0.05) elevated concentrations of Ca2+, Mg2+, NO3-, and TN in post-harvest clearcuts as compared to other treatments. A statistically significant decrease in SO42- was observed in post-harvest clearcuts. The leaching and potential loss of soil nutrients from these soils indicates that management plans for Missouri Ozarks forest soils should include considerations for maintaining soil nutrient levels to sustain forest productivity.