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The article defines the features and principles of researches of soilforming processes in the reference’s and destructive edaphotopes. It is concluded that particularly significant and important ecological role of soil-forming processes in the steppe of edafotop providing the needs of agriculture, forestry, water, utilities and other industries. The important soil-forming processes highlits in the era of growing human pressure on natural ecosystems.

A chuva provoca a modificação da estrutura superficial do solo levando ao desenvolvimento de crostas. Este estudo avaliou a dinâmica da formação de crostas superficiais por meio da análise e descrição micromorfológica de lâminas delgadas. O experimento foi conduzido em 2009 e 2010. Em parcelas de 15 x 30 m, foram implantados os diferentes sistemas de preparos do solo: preparo convencional (PC), preparo reduzido (PR) e sem preparo (SP). Dentro das parcelas instalaram-se as microparcelas de 1 x 1m e aplicaram-se diferentes lâminas de chuva simulada (0, 27, 54 e 80 mm) com intensidade de 80 mm h-1. Nas microparcelas, coletou-se uma amostra indeformada em que consistia em um bloco de solo de 0,07 x 0,05 x 0,12 m. Os blocos foram impregnados com resina e após endurecimento e secagem total foram confeccionadas lâminas delgadas (4,5 x 8 cm), descritas, utilizando microscópio óptico. Foi confeccionada uma lâmina delgada para cada chuva (0, 27, 54 e 80 mm) e para cada preparo do solo. Todos os sistemas de preparo avaliados demonstraram presença de crostas; entretanto, o processo de formação das crostas ocorreu com dinâmica diferenciada em cada sistema de preparo. O preparo convencional apresentou formação de crostas a partir de 27 mm de chuva aplicada. O aumento da lâmina de chuva aplicada causou maior degradação da estrutura superficial e maior espessura da camada encrostada. O preparo reduzido e o sistema sem preparo apresentaram condições de superfície irregulares com as chuvas aplicadas, ou seja, não demonstraram modificações constantes da superfície do solo e na formação das crostas, com o aumento da chuva, como constatado no preparo convencional. A análise das lâminas delgadas e a descrição micromorfológica permitiram satisfatória observação e conclusão dos processos e da dinâmica envolvida na formação de crostas.On the soil surface, rainfall modifies the soil surface structure promoting crust development. This study evaluated the dynamics of soil crusting, through description and micromorphological analysis of thin sections in 2009 and 2010. In 15 x 30 m plots, the management systems conventional tillage (CT), reduced tillage (RT) and no tillage (NT) were assessed. Within the plots, 1 x 1 m micro-plots were installed to test different levels of simulated rainfall (0, 27, 54, and 80 mm) at an intensity of 80 mm h-1. From these micro-plots, an undisturbed sample (soil block of 0.07 x 0.05 x 0.12 m) was taken. The blocks were resin-impregnated and after hardening and drying, thin sections (4.5 x 8 cm) were prepared and described using optical microscopy. One thin section was prepared per rainfall level and soil tillage system. Crusts were formed in all tillage systems, however, the process of crust formation was different in each system. Under conventional tillage, crusting was observed after 27 mm rain. A higher rain level increased the degradation of the surface structure and thickness of the crust layer. Under reduced tillage and no-tillage the surface conditions were irregular after the applied rainfall, i.e., the changes in the soil surface and in crust formation were not constant with increasing rain levels, unlike under conventional tillage. The analysis of thin sections and micromorphological description allowed satisfactory conclusions on the processes and dynamics involved in crust formation.

The examination of glacial sediments in thin sections has become a common procedure in recent years. Apparent sand grain orientation (microfabric) in thin sections is one of the key elements marking certain microstructures. In an attempt to make till micromorphology studies less subjective and investigate the orientation of sand-sized particles in tills, we have developed an image analysis procedure to measure and analyse the spatial distribution of the till microfabric. We studied 13 thin sections of the Weichselian subglacial till and basal shear zone outcropping in the Baltic Sea bluffs at the Ziemupe site in western Latvia. The results were visualized as a two-dimensional grid of rose diagrams covering the area of the thin section and were compared to macrofabric. We found that in larger areas microfabric, although much weaker than macrofabric, coincides with macrofabric orientation. In the sub-centimetre scale till microfabric in short distances appears to be highly variable both in strength and preferred orientation, and a domain-like pattern appears.

Black mats are organic-rich sediments and soils that form in wet environments associated with spring discharge. Micromorphological and geochemical analyses of 25 black mats dating to the Younger Dryas Chronozone (12.9–11.7 ka) and early Holocene were conducted to determine their composition and depositional environment. Samples were collected from Arizona, New Mexico, Texas and Nevada. Micromorphological analyses were conducted on thin sections using polarized and blue fluorescent light. These analyses determined that black mats contain humic acids, fine (5–20 μm) plant fragments, diatoms, phytoliths, and gastropods. The dominant type of organic matter in black mats is derived from herbaceous plants, contradicting previous studies that supported algal or charcoal sources. Differences in the micromorphological characteristics of the samples revealed that black mats formed as three different types, organic horizons, moist soils and, ponded sediments, depending on their topographic position in relation to the water table. The microscopic evidence found in black mats supports the presence of widespread wet environments in Nevada and Arizona during the Younger Dryas Chronozone, clearly indicating a sustained period of greater effective moisture, optimal for spring discharge and black mat formation. [ABSTRACT FROM AUTHOR]

Abstract: The Swiss Basel-Gasfabrik site represents an important Celtic settlement of urban character. Two species of intestinal parasites, Trichuris sp. and Ascaris sp., were identified in micromorphological thin sections from settlement pits. Species identification is complicated by taphonomic effects as well as the random representation of samples and cuts. Parasite eggs are encountered within and beyond original depository contexts due to water displacement and bioturbation. Our findings introduce micromorphology as a new means of paleoparasitological research which augments classical procedures. It captures parasite remains directly in their original microstratigraphic setting, thus providing information not to be obtained by classical flotation. Our observations are relevant for the selection of suitable sampling sites, sampling strategies, and methods of recovery and identification of paleoparasitological data in archeological sediments. They create new insights into site specific parasite dispersal and living conditions in the Late Iron Age. [Copyright &y& Elsevier]

Abstract: Water infiltration is a crucial process for functioning of vegetated buffer zones (BZ). Structure of a clayey surface soil of three differently managed BZs, i.e., 1) natural with no treatment, 2) harvested once a year and 3) grazed by cattle was investigated in this study. Soil macro pores (>50μm) were characterized by qualitative description and quantitative image analysis of soil thin sections in order to assess their capability to water infiltration. Less than 10% of the macro pores consisted of rounded and irregular pores smaller than 300μm indicating root activity. Instead, macro porosity was clearly dominated by elongated pores characterized by irregularity, expressing the complexity of the pore system. This pore pattern appeared in thin sections as weak or moderate ped separation suggesting good water infiltration when initially dry. Partial accommodation of pores may result in decrease of hydraulic conductivity, as these pores tend to close upon wetting and swelling. In the grazed site a platy structure was observed due to hoof pressure, which may further impair the hydraulic properties of soil. Moisture and temperature related processes (shrink–swell, freeze–thaw, and water saturation) are thought to be conducive to the aggregation and rearrangement of soil structure around the year, resulting in a complex pore system with low intra-aggregate porosity. In addition, wet periods typical of boreal soils result in clay dispersion and formation of aggregate-related pedofeatures of dense infillings, described as fine clay intrusions. [Copyright &y& Elsevier]

Abstract: This paper aims to describe the use of thin sections/micromorphology in the sedimentology of unconsolidated sediments. It provides examples of the use of thin sections in a variety of sedimentary environments, from fault gouge, through caves and volcanics to aeolian, fluviatile, marine, periglacial and glacial. It demonstrates that in the latter three fields the use of micromorphology is relatively widespread and that in glacial sedimentology it has revolutionised our way of thinking about subglacial sediments. Although micromorphology has been mainly descriptive so far, methods of quantification observations are demonstrated. Some of the important aspects of micromorphology are its use for microstratigraphy and the possibility of relating observations to documented processes thereby allowing a more robust sedimentological interpretation of modern and ancient sediments. [Copyright &y& Elsevier]

Abstract: A large industrial area on the dry land facing the Venice lagoon, in North East Italy, is currently being reclaimed. This paper focuses on the modifications of the structural characteristics occurring on the surface and along the profile of some industrial waste in an area that has been colonized by woody plants. Qualitative micromorphological observations of thin sections of undisturbed soil samples showed that all samples taken from the surface layer (0–5 cm) of the woody area looked similar to samples from natural forest soil abundant in organic matter and with an open and crumby structure rich in pores. In some samples the substrate alteration was still evident at a depth of 20–25 cm. Quantitative data on the soil pore system obtained by image analysis were consistent with previous findings and total porosity decreased along the profile from about 30% to less than 5%. Elongated pores were the most abundant in the majority of samples, and the intermediate size class (0.2–1.0 mm) was the most representative. Good structural properties were also confirmed by the cracking patterns of artificially dried surface soil samples, which showed a network of fine cracks. Comparisons are also given with an adjacent area where phytoextraction trials were carried out according to common agricultural practices. [Copyright &y& Elsevier]