417-1 The Effects of Clear-Cutting on Mineral Soil Carbon Pools in Northeastern Hardwood Forests.
See more from this Division: SSSA Division: PedologySee more from this Session: Disturbance As a Driver of Soil and Ecosystem Change (includes student competition)
The present study investigated mineral soil C pools in forests that were harvested in the last century and compared them to pristine forests in the same region. We hypothesized that mineral soil C pools would be lower in harvested forests versus forests that had not been harvested for >100 years. We collected 60-cm mineral soil cores from twenty forest stands across the Northeastern US, representing seven geographic areas and a range of times since last harvest. We compared recently harvested forests to >100-year-old forests and used an information theoretic approach to model C pool dynamics over time after disturbance. We used py-GCMS to quantify and describe the suite of C compounds present in three density fractions of the mineral soil at sites with different management histories.
There was a trend of higher soil C pools in >100-year-old forests than in harvested forests, but the differences were not statistically significant. Differences between harvested and older forests increased with mineral soil depth. We found a significant negative relationship between time since forest harvest and mineral soil C pools. The relationship between C:N ratio and percent soil organic matter (SOM) varied between harvested and >100-year-old forests. Soil C compounds varied among sites with different management histories, particularly in the heavy fraction of the mineral soil. Our results are consistent with previous studies that found that soil C pools recover slowly to disturbance,
See more from this Session: Disturbance As a Driver of Soil and Ecosystem Change (includes student competition)