Recent studies suggest increased fire frequency may impair soil chemistry, but few studies have examined long-term effects of repeated, frequent prescribed fires on forest soil properties in the southeastern Coastal Plain, USA. In this study, forest soil chemistry at the 0–10 and 10–20 cm mineral soil depths of sandy surface horizons (Entisols and Spodosols) were compared among units burned 0, 4, 6, and 8 times between 2004 and 2015 and 0 and 20 times between 1978 and 2015 in a longleaf (Pinus palustris Mill.)–loblolly (Pinus taeda L.) pine savanna at the Tom Yawkey Wildlife Center (Georgetown, SC, USA). At the 0–10 cm soil depth, soil pH (p = 0.00), sulfur (p = 0.01), calcium (p = 0.01), iron (p < 0.01), manganese (p < 0.01), and aluminum (p = 0.02) treatment means differed (2004–2015). Calcium and manganese displayed positive, significant relationships and sulfur displayed a negative, significant relationship with increasing fire frequency (p < 0.05). However, correlation of these relationships was low (r² ≤ 0.23). Using linear contrasts to compare the mean of all fire treatments (20 fires from 1978 to 2015) to the mean of the unburned compartment, sulfur (p = 0.01) and iron (p < 0.01) were less in soils from the burned compartments. At the 10–20 cm soil depth, soil pH (p = 0.01), manganese (p = 0.04), phosphorus (p = 0.01), potassium (p = 0.02), and iron (p < 0.01) treatment means differed (2004–2015). Potassium displayed a negative, significant relationship and soil pH displayed a positive, significant relationship with increasing fire frequency (p < 0.05). Correlation of these relationships was low (r² ≤ 0.16), however. Using linear contrasts to compare the mean of all fire treatments (20 fires from 1978 to 2015) to the unburned compartment, potassium (p = 0.00) and iron (p < 0.01) were less in soils from burned compartments. These results are inconsistent with studies suggesting that forest soil chemistry is substantially altered by increased fire frequency and support other studies from this region that have documented minimal or temporary soil chemical changes associated with frequent prescribed fires.

Short- and long-term impacts of wildland fires on forest floor properties and erosion potential were examined at three locations in the Central Appalachian region, U.S.A. In 2018, two wildfires were investigated within six months of burning on the George Washington–Jefferson National Forest (GWJNF) in Bland County, Virginia and the Monongahela National Forest (MNF) in Grant County, West Virginia. An additional wildfire was studied eight years post-fire on the Fishburn Forest (FF) in Montgomery County, Virginia. A 2018 prescribed fire was also studied within six months of burning on the MNF in Pendleton County, West Virginia. Litter and duff consumption were examined to evaluate fire severity and char heights were measured to better understand fire intensity. The Universal Soil Loss Equation for forestlands (USLE-Forest) was utilized to estimate potential erosion values. For the 2018 comparisons, litter depth was least as a result of the wildfires on both the MNF and GWJNF (p < 0.001). Wildfire burned duff depths in 2018 did not differ from unburned duff depths on either the MNF or GWJNF. Eight years after the FF wildfire, post-fire litter depth was less than that of an adjacent non-burned forest (p = 0.29) and duff depth was greater than that of an adjacent non-burned forest (p = 0.76). Mean GWJNF wildfire char heights were greatest of all disturbance regimes at 10.0 m, indicating high fire intensity, followed by the MNF wildfire and then the MNF prescribed fire. USLE-Forest potential erosion estimates were greatest on the MNF wildfire at 21.6 Mg soil ha⁻¹ year⁻¹ due to slope steepness. The next largest USLE-Forest value was 6.9 Mg soil ha⁻¹ year⁻¹ on the GWJNF wildfire. Both the prescribed fire and the 2010 wildfire USLE-Forest values were approximately 0.00 Mg soil ha⁻¹ year⁻¹. Implications for potential long-term soil erosion resulting from similar wildfires in Central Appalachian forests appeared to be minimal given the 2010 wildfire results.

The national Fire and Fire Surrogate (FFS) study was initiated more than two decades ago with the goal of evaluating the ecological impacts of mechanical treatments and prescribed fire in different ecosystems across the United States. Since then, 4 of the original 12 sites remain active in managing and monitoring the original FFS study which provides a unique opportunity to look at the long‐term effects of these treatments in different regions. These sites include California (Blodgett Forest Research Station), Montana (Lubrecht Experimental Forest), North Carolina (Green River Game Land), and Ohio (Ohio Hills). Although regions differed in ecosystem type (e.g., conifer‐ vs. hardwood‐dominated), the overall goals of the FFS study were to promote desirable, fire‐adapted species, reduce fire hazard, and improve understory diversity. Our study uses multivariate techniques to compare how these desired outcomes were maintained over the last 20 years and discusses whether we would modify the original treatments given what we know now. Our findings indicate that mechanical treatments and prescribed fire can promote desired tree species, mitigate potential fire behavior by reducing fuels and retaining larger‐sized trees, decrease tree mortality, and stimulate regeneration—effects that are still apparent even after 20 years. However, we also found that maintaining desired outcomes was regionally specific with western sites (California and Montana) showing more desirable characteristics under mechanical treatments, while the eastern sites (North Carolina and Ohio) showed more desirable characteristics after prescribed burning. The beneficial effects of treatment were also more apparent in the long term when sites followed up with repeated treatments, which can be adapted to meet new objectives and conditions. These findings highlight the FFS study as an invaluable resource for research and provide evidence for meeting long‐term restoration goals if treatments can be adapted to ecosystem type, be maintained by repeated treatments, and accommodate new goals by adapting treatments to changing conditions.

From 2001–2018, a series of fuel reduction and ecosystem restoration treatments were implemented in the southern Appalachian Mountains near Asheville, North Carolina, USA. Treatments consisted of prescribed fire (four burns), mechanical cutting of understory shrubs and mid-story trees (two cuttings), and a combination of both cutting and prescribed fire (two cuts + four burns). Soils were sampled in 2018 to determine potential treatment impacts for O horizon and mineral soil (0–10 cm depth) carbon (C) and nitrogen (N) and mineral soil calcium (Ca), magnesium (Mg), phosphorus (P), potassium (K), and pH. Results suggested that mean changes in O horizon C and N and mineral soil C, N, C:N, Ca, and P from 2001–2018 differed between the treatments, but only mineral soil C, N, C:N, and Ca displayed differences between at least one fuel reduction treatment and the untreated control. One soils-related restoration objective was mineral soil N reduction and the cut + burn treatment best achieved this result. Increased organic matter recalcitrance was another priority, but this was not obtained with any treatment. When paired with previously reported fuels and vegetation results from this site, it appeared that continued use of the cut + burn treatment may best achieve long-term management objectives for this site and other locations being managed for similar long-term restoration and fuels management objectives.

Water quality best management practices (BMPs) developed for conventional forest harvests may be adequate for biomass harvests, yet quantitative data is lacking. This study compared estimated erosion, operational feature areas, BMP implementation rates, ground cover characteristics, and downed woody debris quantities following biomass and conventional harvests in the mountains of Virginia. Haul roads on biomass harvests had significantly higher estimated erosion rates (P = 0.064) and masses (P = 0.045) than conventional harvests, but conventional harvests had higher erosion contributions from skid trails (P = 0.089) and averaged more estimated erosion mass overall, despite being significantly smaller in size (P = 0.054). There was significantly less area in heavy slash (P = 0.076) and lower estimated mass of residual downed woody debris (P = 0.001) on biomass sites than conventional sites (10.98 and 27.95 tons/ac, respectively). Site-wide BMP implementation scores (P = 0.041), streamside management zones (SMZs) (P = 0.024), and skidding (P = 0.063) were significantly higher on biomass sites than conventional sites. BMP implementation scores were significant predictors of estimated erosion rates (P < 0.001, R² = 59%), indicating that adequate levels of existing water quality BMPs are effective for erosion control on both conventional and biomass harvests.