5 research outputs found
Genesis and preservation of patterned ground in permafrost non-affected soils-Central Apennines, Italy
Several research have been focused on the polygenetic origin of patterned ground soils, ascribing to the freeze-thaw cycles the driving mechanism in the sorted features genesis. Therefore, this type of soils may be considered strictly associated with permafrost-affected areas because freezing and thawing of soil are generally related to the seasonal frost and/or the occurrence of the active layer. Since permafrost can reach mid-latitudes depending on local microclimatic conditions, the Majella Massif (central Apennines, Italy) gained interest because of the presence of periglacial landforms (rock glaciers, kettle holes, and patterned ground), although no direct obser-vations and measurements indicating the occurrence of permafrost have been reported. This work was aimed to determine the genesis and preservation of patterned ground on the Majella Massif through monitoring of soil and air temperatures and derived parameters, and soil characteristics.Results suggested that permafrost was absent at a depth <2 m. However, this did not exclude the presence of deep and sporadic permafrost, as a relict form of a shallower permafrost present in ancient climatic phases. Although during these phases permafrost-driven processes were probably responsible for the formation of the patterned ground, nowadays the preservation and reorganization of this periglacial form is driven by phenomena including superficial freeze-thaw cycles and snow redistribution due to wind. Specifically, the preservation of the miniature patterned ground has been ascribed to shallower phenomena related to the water-holding capacity of the soil and to freeze-thaw cycles of the upper soil layers, which resulted in differential frost heave and segre-gation of coarse fragments and fines
Influence of forest management on nutrient stock (C and Pav) and earthworm fauna in chestnut woods in central Italy
Zoogenic soil horizons-termite ecosystem engineers in different agro-ecological regions of Mozambique
Termite nests represent a typical ecosystem engineered to produce a solid and long-lasting home where in-dividuals are protected from predators, rainfall, and sunlight, while maintaining requisite temperatures and humidity. To achieve this, termites translocate and rework soil material as a unique pedogenic force, exposing it to soil genesis factors that may vary temporally. To date, limited information exists on zoogenic soil genesis from termites, with a few reports on the pedomorphological characterization of termite mounds and of the different genetic horizons developed therein. The aims of this work were to report the pedomorphological and physico-chemical characterization of termite mounds in two selected sub-tropical agro-ecological zones of Mozambique and to define the genesis of zoogenic soil horizons that form termite mounds. Common soil features like channels and galleries are related to the ability of termites to create a suitable environment for the colony and are created through modification and reworking of soil and subsoil materials. Because of this, termites can be considered as the main pedogenic force, which fosters horizons different in pedomorphological and physicochemical features with respect to the surrounding soil. In view of this, new suffixes or diagnostic horizons may be useful in the characterization of soil horizons affected by bioturbation