Role of Vegetation in Mitigating Soil Quality Impacted by Forest Harvesting

The initial growth response of loblolly pine (Pinus taeda L.) to competition control is well documented. However, the benefits of competing vegetation to soil quality have not been thoroughly investigated. A study was conducted: (i) to evaluate the effectiveness of bedding site preparation in recovering soil processes and productivity following disturbance; and (ii) to determine if different levels of vegetation control have differential effects on soil processes that aid in the recovery and maintenance of soil productivity. Study plots were established on a wet pine flat on South Carolina's Coastal Plain. Treatments included a range of three disturbance classes (undisturbed, compression tracked, and churned), two site preparation treatments (flat planted and bedded), and a gradient of vegetation control (no vegetation control, operational level weed control, and complete weed control). Compacted soils generally increased in bulk density (14%) and decreased in macroporosity (25%) and hydraulic conductivity (69%) compared with undisturbed treatments. Churning had no significant net effect on the soil physical properties measured; however, it did increase net N mineralization by over 100% on flat‐planted treatment plots. Bedding fully ameliorated the effects of soil compaction based on the physical properties measured. Trends suggest some improvements in soil quality with increasing levels of non‐crop vegetation biomass; however, during 2 yr of operational vegetation control, the beneficial effects of the non‐crop vegetation were marginal.