Regeneration of Belowground Properties and Nutrient Pools in Soil after Compaction: Response to the Reforestation with Native Tree Species in the Hyrcanian Forest

Abstract

The current study characterizes the regeneration in the floor layer and topsoil at a depth of 0-10 cm in the skid trails, dealing with the reforestation of four tree species (FE; Fraxinus excelsior, PA; Prunus avium, AC; Acer cappadocicum, and QC; Quercus castaneifolia) after clear-cutting in degraded forests, comparing to the undisturbed natural forest (CB-PP; Carpinus betulus-Parrotia persica). Results showed significant differences in litter layer properties among tree species, with the highest litter thickness, C, and C/N ratio under QC and AC, and the greatest litter N in CB-PP and FE. FE plantation resulted to enhance soil bulk density (1.14 g cm −3), total porosity (55.85%), macroporosity (37.72%), penetration resistance (1.43 MPa), soil moisture (33.4%), and aggregate stability (51.7%), compared to other tree plantations, whereas these values under the FE plantation were still lower than those of the CB-PP stand over a 30-year period after logging operation. Litterfall on soil surface under planted tree species (FE and PA in particular) can be considered as a primary food resource (i.e., soil C and soil organic matter) driving biological and microbial activities. Results of the current study can improve our knowledge to select suitable tree species to maintain soil quality and nutrients pool to deal with ecosystem restoration programs and reforestation in degraded forest areas.