The effect of landform on soil microbial activity and biomass in a Hyrcanian oriental beech stand

The Influence of Slope Positions on the Recovery Response of Compacted Soil Properties and Enzyme Activity in an Oriental Beech Stand in the Hyrcanian Forests, Iran

“…The current study demonstrated that soil physical, chemical, and biological properties were influenced by topography and more specifically slope positions within the area trafficked by ground-based machines. Particularly, soil moisture and organic matter content were regulated by topography and slope positions, which is in line with [4,7,9]. Because water is directly involved in chemical and biological activities of decomposition and degradation as well as in physical degradation, changes of soil moisture directly affected the evolution of soil profiles and biological activities of the soil [8,38].…”

“…The lower C/N ratio of soil was found in the TS followed by S > BS > UND areas. Previous studies reported that the slope position can introduce a microclimate, which in turn regulated soil moisture and solar radiation and resulted in spatial variability of SOC, N, and C/N ratio [3,9,46]. The higher humic and fulvic acids were observed in the TS treatment due to a higher soil moisture availability, which resulted in improved soil physical and chemical properties.…”

“…Four years after skidding operations, the recovery levels of soil bulk density and penetration resistance were higher in the TS than in the BS and S treatments, compared to the UND areas. Furthermore, by transporting the eroded materials and organic matter as well as litters from S to the TS position on bare mineral soil, water storage capacity augmented, which in turn suppressed the runoff and soil loss [9,17,41]. Consequently, SOC and soil moisture were enhanced and augmented soil fauna, which in turn resulted in reclamation of soil aggregates [42,43].…”

“…Variations in topographic characteristics such as elevation, slope gradient, and slope aspect lead to immense changes in climatic and soil factors that contribute to the soil organic carbon (SOC) variability [1,7,8]. In general, soil physical, chemical, and biological indices, as well as enzyme activity are affected by parent material, vegetation, climate, and topographic conditions [3,7,9]. Generally, the slope position and the slope aspect regulate the hydrological processes and the level of solar radiation reaching the ground, which, in turn, introduces microclimates in smaller area [7,8].…”

“…Topographic features such as slope gradient, shape (convex or concave), position (the summit, shoulder, backslope, footslope, and toeslope), and streams are key factors that influence the development and variability in soil properties, nutrient cycling, decomposition rate of organic matter, and soil-air gas exchange [1,5,8]. In the Hyrcanian forests located in northern Iran, soil water content, SOC, and total nitrogen as well as soil microbial respiration were significantly affected by the catena shape and slope position [9]. In the Van Lake Basin, Turkey, Karaca et al [1] revealed that the various topographic locations also significantly influenced soil properties including soil texture, electrical conductivity (EC), pH, lime, organic matter, and nutrient content as a result of materials being leached, transported, and accumulated.…”