Soil efflux (SEF) is an important component in the global carbon cycle. The combination of root and microbial respiration, SEF is often used as a measure of biological productivity in the soil. Although SEF has been widely studied, some areas have been neglected, including the effect of timber harvest management on SEF and SEF in different soil horizons. Timber harvesting compacts the soil, removes standing vegetation, increases debris, alters the microclimate, etc., all of which could potentially alter SEF. The Missouri Ozark Forest Ecosystem Project (MOFEP) is a long-term study in which the Missouri Department of Conservation (MDC) installed experiments of single-tree uneven-age (UAM), clear-cut even-age (EAM), and control no-cut (NHM) timber harvests to find ecosystem-management alternatives. To determine the effect of timber harvest on subsurface SEF, nine soil pits, three in each treatment, were dug to directly measure the magnitude of changes in SEF across the soil profile.