Entity

Time filter

Source Type

Krásná Lípa, Czech Republic

Varilova Z.,Bohemian Switzerland National Park Administration | Prikryl R.,Charles University | Cilek V.,Academy of Sciences of the Czech Republic
Environmental Earth Sciences | Year: 2011

The dominant factors affecting the development of weathering forms on the Pravčice Rock Arch (PRA) (Bohemian Switzerland National Park, Czech Republic) are discussed, based on the in situ monitoring of weathering forms, as well as on laboratory studies of materials taken from this site. The in situ monitoring shows the progressive development of distinct weathering forms (delamination of case-hardened rock surfaces, cyclic efflorescence, and granular disintegration of exposed weakly cemented rock mass) in specific portions of the PRA, whose location is controlled by lithology, jointing/local hydrodynamics, and exposure to climatic factors. From the analysis of efflorescence, the dominance of sulphates is evident; particularly of gypsum and alums. However, the synergistic effects of the several salt species (that also include minor nitrates and chlorides) upon the mechanical disintegration of sandstone can be expected. © 2011 Springer-Verlag. Source


Varilova Z.,Bohemian Switzerland National Park Administration | Navratil T.,Academy of Sciences of the Czech Republic | Dobesova I.,Academy of Sciences of the Czech Republic
Water, Air, and Soil Pollution | Year: 2011

The protected area "Bohemian Switzerland National Park" with its characteristic sandstone landscape was influenced by the long-term air pollution and acidic deposition within the area known as Black Triangle (located where Germany, Poland, and the Czech Republic meet, is one of the Europe's most polluted areas). The local Upper Cretaceous sandstone is subhorizontally stratified, fine- to coarse-grained, quartz dominated, with low content of clay minerals. One of the significant negative effects of the intensive acidic deposition on sandstone outcrops has been identified as chemical (salt) weathering, i.e., a process when the porous sandstone rock is except of chemical influence attacked also by force of crystallization of growing salts crystals. Anions NO 3- together with SO 42- and cation NH 4+ were the most abundant solutes in bulk precipitation samples. Current (2002 to 2009) bulk deposition fluxes of SO 42- determined at three sites directly in the National Park indicate decline from 23 to 16 kg-1 ha-1 year -1. Infiltration of bulk precipitation solutes into the sandstone mediates the weathering processes. Natural outflow of sandstone pore-water (sandstone percolates) can be sampled only during certain days of year when the sandstone becomes saturated with water and percolates drip out on small number of sites from roofs of overhangs. Under usual conditions percolation water evaporates at the sandstone surface producing salt efflorescences-the typical example is Pravčická brána Arch locality. The average pH of the dripping sandstone percolates was 3.76. Concentration of SO 42- and Al in sandstone percolates reached up to 46 and 10 mg L -1. The concentration of Al in percolates has been 160-fold greater the one in the precipitation samples suggesting the sandstone as a source. The water O and H isotopic composition of percolates has been virtually identical to precipitation samples, indicating thus relatively short residence time of the solutions within the sandstone pore-spaces. Evaporation experiments with bulk precipitation and percolate samples proved possible origin of some Ca in bulk precipitation and the sandstone rock as the source of Al and possibly of K for the salt efflorescence identified on Rock Arch body. © 2011 Springer Science+Business Media B.V. Source


Plasek V.,University of Ostrava | Sawicki J.,University of Warmia and Mazury | Markova I.,Bohemian Switzerland National Park Administration | Wierzcholska S.,Wroclaw University
Acta Societatis Botanicorum Poloniae | Year: 2011

Orthotrichum affine var. bohemicum Plášek & Sawicki, var. nova, is a confirmed record of a new variety from the Czech Republic. The new taxon is described and illustrated by photos and drawing. It is characterized by having superficial stomata and a peristome with 16 endostome segments (practically as long as exostome teeth). Molecular data indicating the phylogenetic placement of the species are presented. © The Author(s) 2011. Source


Bogusch P.,University of Hradec Kralove | Blazej L.,Vlastivedne museum a galerie v Ceske Lipe | Tryzna M.,Bohemian Switzerland National Park Administration | Tryzna M.,Czech University of Life Sciences | Heneberg P.,Charles University
European Journal of Forest Research | Year: 2015

Forest fire remains among the most controversial topics in nature conservation. Here, we address changes in abundance and species composition of the bee and wasp community following a temperate forest crown fire that led to nearly complete defoliation and dieback of trees within 2 years. We found a highly dynamic community of 252 bee and wasp species (representing 18.8 % of total bee and wasp species known from the Czech Republic) that utilized 1–7-year-old burned forest stands. Species richness in the burned forest stands was significantly higher than that recorded in nearby forest that had been unaffected by any recent fire. The unburned forest hosted only 88 species. We found 42 red-listed species, of which 40 were present in the burned forest, while only 12 were present in the control forest. Numerous early- and late-responding species were detected, but maximum species diversity was reached 3 years after the fire. Only 7 of the total of 261 species were limited to the forest that was unaffected by any recent fire. A management regime that supported the presence of bare sand and heather patches, and removal of all but solitary pine trees, was found to be insufficient to support the full spectrum of forest fire-dependent species. This was mainly due to the absence of charred or decaying dead wood, which is otherwise utilized by numerous redlisted cavity adopters that are absent in the surrounding cultural landscape. Retaining part of the charred trunks is suggested as a novel post-fire conservation measure. © Springer-Verlag Berlin Heidelberg 2014. Source


Varilova Z.,Bohemian Switzerland National Park Administration | Zvelebil J.,Geo Tools | Palus M.,Institute of Computer Science
Landslides | Year: 2011

Ever wider implementation of information technologies is flooding us by monitoring data. To an efficient risk management, those data have to be processed and assessed in the same rate as they are recorded and transported. Paper demonstrates some methods dealing with intrinsic, nonlinear dynamics of slope system for computerized safety assessment of monitoring time series, their modeling and early warning launching. Analysis and modeling of phase changes - i. e. specific transient states between different developmental stages of dynamics of unstable slope systems, enabled to fix new types of precursors for rock fall warning and to enhance time prediction of rock fall occurrence. Mathematically well based, novel numerical and topological methods from the toolbox of complex system theory were successfully implemented to that challenge. Their pattern-recognition ability, i. e., diagnostic sensitivity, and more realistic results of modeling of time series relevant patterns have reached beyond ranges of regularly used-both the idea- and the data-driven-methods. Moreover, results yielded by phase space analyses are in good agreement with the ones by numerical fractal analyses. Obtained results have strengthened the primary, mainly theoretically based hypothesis; the dynamics of an unstable rock slope has to be considered as behavior of nonlinear, dissipative, non-equilibrium, self-organizing complex system. Correspondingly to the theoretical assumptions, two qualitatively different types of slope system dynamics-near to equilibrium and far from equilibrium states, were identified. All field monitoring data used originated in practice of highly automated, integrated IT system of monitoring assessment, and management of rock fall hazard at sandstone rock walls in the NW Bohemia. © 2010 Springer-Verlag. Source

Discover hidden collaborations