Luděk Šefrna

Vegetation history of chernozems in the Czech Republic

Chernozem is a soil type which can be characterised by a thick dark surface horizon, which consists of organic matter and tends to change into a carbonate horizon or more often into a loess horizon. Chernozem is defined as a zonal soil that has developed under steppe vegetation in a dry continental climate. Nevertheless, chernozems can also be found in central Europe, where there are no climatic conditions for the existence of any steppe. This study is focused on the vegetational aspect of the pedogenesis of chernozems. We have examined three sorts of chernozems for their charcoal and pedological characteristics: the functional chernozems, the chernozems buried in Holocene material and the chernozems buried in Pleistocene material. The charcoal examination has proved the presence of woodland taxa in the areas of chernozems at different periods of time. The results of this study reveal that the high stability of soil organic matter has caused the persistence of chernozems in the areas with prevalent woodland vegetation.

The Amazon River headstream area in the Cordillera Chila, Peru: hydrographic, hydrological and glaciological conditions

Abstract The source of the worlds largest river has fascinated scientists and adventurers for a long time. Extensive studies have been undertaken in the unexplored Llogueta River valley, Cordillera Chila, to identify the main stream of the Amazon River. Analysis of the Lloqueta River network and measurements of its hydrographic and hydrometric characteristics are presented in this study. On the basis of the acquired data, the northern hillside of the Cordillera Chila massif, concretely the basins of four mountainous courses—the Carhuasanta, Apacheta, Ccaccansa and Sillanque rivers—should be regarded as the headwaters territory of the Amazon River. Factors influencing the river system—glaciers and soils—were examined for each catchment. Glacier retreat in the last 50 years has left perennial snowfields only in the highest part of the study area, resulting in modification of the headwater runoff regimes. Preliminary results are afforded by the continual automatic water-level monitoring of the Lloqueta River since June 2008. Our investigations have determined that all types of soil in the area could be classified into two main categories: hydromorphic soils or poorly developed cryic soils. Citation Janský, B., Engel, Z., Kocum, J., Šefrna, L. & Česák, J. (2011) The Amazon River headstream area in the Cordillera Chila, Peru: hydrographical, hydrological and glaciological conditions. Hydrol. Sci. J. 56(1), 138–151.

CHERNOZEM. FROM CONCEPT TO CLASSIFICATION: A REVIEW

In this paper, we put together the most important facts that lead to the research on chernozem. Thanks to the work of V. V. Dokuchaev (1846–1903), chernozem stands at the forefront of pedology. In 1883, Dokuchaev introduced the first concept of chernozem: he defined chernozem as a steppe soil with pedogenesis dominated by a dry continental climate and steppe vegetation, with calcareous parent material. Chernozem is a soil well known for its high agronomical potential; therefore the perception of chernozem as something extraordinary valuable goes back far into history. Our review presents the key factors of the pedogenesis of chernozem by explaining the causes of the high stability of its organic matter and the role of vegetation and fauna in this process. Moreover, it shows that chernozem can have many aspects due to various (a) textures, (b) chemical compositions, (c) influence of water, (d) fauna, or (e) anthropogenic factors. We examine the position of chernozem in numerous national and international soil classifications over time. We have found out that chernozem had been classified, according to its properties, as a “steppe soil”, as a “calcic soil” or as an “isohumic soil”.

Development of Soil Consumption Driven by Urbanization and Pattern of Built-up Areas in Prague Periphery since the 19 th Century

th century till 2010. The results show an extensive soil consumption. The average extent of built-up area increased from less than 1% to more than 13% per cadastre. This extensive development caused consumption of high quality soils and changed the pattern of built-up areas from more compact to less compact built-up areas. The average nearest neighbour distance between built-up patches has increased by more than 38%.

SOIL ORGANIC CARBON DENSITY AND STORAGE IN PODZOLS – A CASE STUDY FROM RALSKO REGION (CZECH REPUBLIC)

The aim of this paper is the characterization of Carbic Podzols in the Ralsko region (Czech Republic) and their role in the soil carbon balance. The emphasis was put on soil carbon density and storage in the subsurface mineral horizons. Soil organic carbon density calculated for the studied podzol in the Ralsko region was 49.97 t ha−1. More than 53% of this carbon is located in the subsurface horizons, below the depth of 30 cm. The soil organic carbon density was visualised for all soil horizons. The reasons for spatial variability in soil carbon densities were sketched. Carbon density, besides other things, depends on the soil horizon’s thickness which is very variable in the case of Carbic Podzols. Therefore, the horizon thickness and its course were visualised as well.