Soil Chemistry following Single-Entry, Dormant Season Prescribed Fires in the Ridge and Valley Province of Virginia, USA

In this study, mineral soil (0-10 cm depth) chemistry [pH, calcium (Ca), carbon (C), magnesium (Mg), nitrogen (N), phosphorus (P), potassium (K)] was measured pre - and post-fire (6 and 14 months post-fire) at two prescribed fire locations near Blacksburg, Virginia, USA. A similar, adjacent, unburned (control) forest was sampled during this time period, as well. Combinations of treatment and time did not indicate significant differences between the control and burned locations for any of the soil chemical variables when burned and control plots were evaluated within each, individual, sampling period (pre-fire, 6 months post-fire, and 14 months post-fire). Differences did exist, however, for some variables when compared across all treatment and time combinations. Differences were also noted for Ca, K, Mg, P, C, and N within the burned plots alone as a result of sampling time. These results agreed with those from other studies in this region that suggest 1) soil chemistry is highly variable, with and without prescribed fire, and 2) short-term changes in soil chemistry following singular, dormant season, prescribed fires are often negligible, particularly when compared to adjacent, unburned, control units. Increased fire intensity, severity, or fire frequency may enhance both short- and long-term post-fire soil responses.

Automated summary

The study found no significant differences in soil chemical variables between burned and control locations at two prescribed fire sites, when evaluated within each sampling period. However, some differences were observed when compared across all treatment and time combinations, particularly within the burned plots.