Since Dokuchaev's investigations of Russian Chernozems, Central European Chernozems were established as steppe soils, with their pedogenesis dominated by humus accumulation as a result of dry continental climate and steppe vegetation, with carbonaceous parent material and bioturbation as other prerequisites. The WRB-FAO classification defined Chernozems by their morphological characteristics, but was biased by the climo-genetic formation model. However, the assumption that modern Central European Chernozems are relics of steppe soils conflicts with palaeobotanical evidence from an early reforestation that started in the Late Glacial, and also with pedological studies that dated Chernozem formation to the Early Holocene. In this review we compile the most important literature on pedogenesis of Central European Chernozems since the 1920s, according to the soil forming factors climate, time, vegetation, relief and man. Our review demonstrates that there is no consensus on the factors controlling the formation, conservation and degradation of Central European Chernozems in published literature. We found that (1) no absolute time of formation could be stated so far, and that (2) Central European Chernozems formed not only under steppe but also under forest vegetation; (3) the spatial distribution of Chernozems and Phaeozems did not correlate with climate conditions or topographic position, and (4) until now no other factors were considered to be responsible for Chernozem development. Recent studies showed that these unknown factors could include anthropogenic activity and vegetation burning as they could form black soils or strongly affect the composition of soil organic matter. We concluded that not all soils classified as Chernozems in Central Europe are steppe soils and thus, as they do not necessarily reflect past climate, the classification may be misleading. Pedogenesis of Chernozems inCentral Europe -A review Eileen Eckmeier a AbstractSince Dokuchaev's investigations of Russian Chernozems, Central European Chernozems were established as steppe soils, with their pedogenesis dominated by humus accumulation as a result of dry continental climate and steppe vegetation, with carbonaceous parent material and bioturbation as other prerequisites. The WRB-FAO classification defined Chernozems by their morphological characteristics, but was biased by the climo-genetic formation model. However, the assumption that modern Central European Chernozems are relics of steppe soils conflicts with palaeobotanical evidence from an early reforestation that started in the Late Glacial, and also with pedological studies that dated Chernozem formation to the Early Holocene.In this review we compile the most important literature on pedogenesis of Central European Chernozems since the 1920s, according to the soil forming factors climate, time, vegetation, relief and man.Our review demonstrates that there is no consensus on the factors controlling the formation, conservation and degradation of Central European Chernozems in pub...

The incorporation of plant biomass into soil usually leads to long-chain n-alkanes with a relative predominance of odd carbon numbered homologues. Contrastingly, an increase in short-chain even carbon numbered n-alkanes was found in charred biomass with progressing temperatures. We applied lipid analysis to buried ancient topsoils that contained charred organic matter and to corresponding control soils, which were characterized by a lighter color and lower contents of charred materials. Commonly, the proportion of lipid extracts was found to be lower in the ancient soil than in the control samples, which indicated an enhanced degradation of organic matter, e.g., by thermal degradation. All samples displayed a particular pattern of short-chain and even carbon numbered n-alkanes (maximum at n-C16 or n-C18). The ratios CPI (carbon preference index) and ACL (average chain length) for the investigated soil samples matched the ratios found for maize and rye straw charred at 400 °C or 500 °C, respectively. These molecular ratios indicate the presence of charred biomass. The predominance of short-chain and even carbon numbered n-alkanes was a result of thermal degradation of biomass. The degradation products were preserved in ancient soils and could be applied as molecular markers in archaeological or palaeoenvironmental research.Author's personal copy b s t r a c tThe incorporation of plant biomass into soil usually leads to long-chain n-alkanes with a relative predominance of odd carbon numbered homologues. Contrastingly, an increase in short-chain even carbon numbered n-alkanes was found in charred biomass with progressing temperatures. We applied lipid analysis to buried ancient topsoils that contained charred organic matter and to corresponding control soils, which were characterized by a lighter color and lower contents of charred materials. Commonly, the proportion of lipid extracts was found to be lower in the ancient soil than in the control samples, which indicated an enhanced degradation of organic matter, e.g., by thermal degradation. All samples displayed a particular pattern of short-chain and even carbon numbered n-alkanes (maximum at n-C 16 or n-C 18 ). The ratios CPI (carbon preference index) and ACL (average chain length) for the investigated soil samples matched the ratios found for maize and rye straw charred at 400 C or 500 C, respectively. These molecular ratios indicate the presence of charred biomass. The predominance of short-chain and even carbon numbered n-alkanes was a result of thermal degradation of biomass. The degradation products were preserved in ancient soils and could be applied as molecular markers in archaeological or palaeoenvironmental research.

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