Abstract
Ground-based skidding operations performed with heavy machinery have drastic effects on forest soils, which normally culminate in an increased soil bulk density and removal of the litter layer. We aimed to assess the efficacy of different tree species litter on the recovery of soil physical, chemical, and biological properties over a 5-year period in the Hyrcanian forests, northern Iran. Therefore, treatments included 45 combinations of five treatments (undisturbed area—UND, untreated trail or bare soil—U, and three leaf litter types: pure beech—B, beech-hornbeam—B-H, and beech-hornbeam-maple—B-H-M) replicated in three plots in three transects. Results show that the highest litter thickness, and concentrations of C and N in the litter were observed in the UND treatment. The litter C/N ratios were highest in the untreated trail (U; 27.52) followed by B > B-H ≈ B-H-M > UND treatments. The highest recovery of soil bulk density, total porosity, macroporosity, soil penetration resistance, and aggregate stability was observed on the B-H-M and B-H treatment followed by the B treatment. The highest recovery values of pH, C, N, C/N ratio, C and N sequestration recovery rates were observed on the B-H-M treatment, followed by the B-H treatment. Significantly higher values of available nutrients (P, K, Ca, and Mg), earthworm density, and biomass were found in the UND treatment followed by B-H-M ≈ B-H > B treatment, while the lowest amounts of available P, K, Ca, and Mg were detected for the U trail. The high-quality litter species (hornbeam and maple) allowed for better recovery of the soil organic matter and increased nutrient availability compared to the lower quality litter (beech). We can conclude that by applying the different litters on compacted soil, the measured soil properties were significantly improved at the B, B-H, and B-H-M treatments. Nevertheless, the soil properties following the B, B-H, and B-H-M treatments still demonstrated significant differences with the UND treatment, even over a 5-year period.
Highlights
Ground-based skidding operations are done with heavy machinery and normally entail machine traffic and load movement performed directly on forest soils
Our results indicate that two high-quality litter species were able to facilitate the recovery of soil organic matter and nutrients availability better than the low-quality litter; these results are in line with the findings of previous studies [42,45,46,47,48]
We examined the effects of tree species litter as mulch on compacted soil in the skid trails to assess the efficacy of the tree species litter (pure beech (Fagus orientalis)—B, beech-hornbeam (Carpinus betulus)—B-H, and beech-hornbeam-maple (Acer velutinum)—B-H-M) on the recovery of litter and soil physical, chemical, and biological properties, compared to untreated skid trail (U), and undisturbed area (UND) over a 5-year period in the Hyrcanian forests (Iran)
Summary
Ground-based skidding operations are done with heavy machinery and normally entail machine traffic and load movement performed directly on forest soils. These mechanized activities can have severe effects on the quality of the forest soil [1,2,3], decrease total porosity [4,5], increase penetration resistance [6], decrease gas exchange [7], reduce water infiltration rate [8,9], and remove litter layer [10]. The litter layer abates overland flow and subsequent soil loss [19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
