• Pacini, N., Pechar, L., & Harper, D. M. (2019). Chemical Determinands of Freshwater Ecosystem Functioning. In Freshwater Ecology and Conservation: Approaches and Techniques (Vol. Library od Congress Conttrol Number: 2018948522, pp. 89). Oxford: Oxford University Press.

Chemical equilibria in surface waters stem from complex interactions between physical background and living components of ecosystems. Catchments differ in geological background, climate, and land use; their run-off bears a distinctive chemical ‘fingerprint’. This chapter illustrates how the monitoring of standard parameters, such as oxygen, pH, conductivity, major ions, nutrients, and carbon, can lead to an interpretation of key aspects of the functioning of major ecosystem processes and how chemical constituents may affect the distribution of aquatic organisms. This requires understanding principles that underlie available measurement techniques and it demands a certain familiarity with the intrinsic variability of parameter values and of their chemical interaction. It is not required that field scientists be able to conduct detailed chemical assessments, but all should be able to collect samples yielding high-quality data. Therefore, detailed advice on chemical monitoring practice is provided, including sample collection, filtering, sample processing, and is discussed with the context of several case studies.

• Craft, C., Vymazal, J., & Kröpfelová, L. (2018). Carbon sequestration and nutrient accumulation in floodplain and depressional wetlands. Ecological Engineering, 114, 137-145.

We measured soil organic carbon (C) sequestration and nutrient (nitrogen-N, phosphorus- P) burial in Czech and Midwest U.S. freshwater floodplain and depressional wetlands to evaluate how landscape position and agricultural land use intensity affects C, N, and P retention. Land use in the South Bohemia of the Czech Republic is dominated by forest and pasture, whereas in the Midwest U.S., land use is dominated by row crop agriculture. Cs-137 and ²¹⁰Pb dating of soil cores revealed comparable rates of soil accretion among wetland types, ranging from 0.5 mm/yr in a Czech floodplain wetland to 2.3 mm/yr in a U.S. depressional wetland. Carbon sequestration and N & P burial did not differ among floodplain (47 + 14 g C/m²/yr, 3.7 + 1 g N/m²/yr, 0.47 + 0.16 g P/m²/yr) and depressional wetlands (50 + 19 g/m²/yr, 3.6 + 1.3 g N/m²/yr, 0.51 + 0.14 g P/m²/yr). However, sediment deposition in Czech floodplain and depressional wetlands was only 10–50% (150–340 g/m²/yr) of rates measured in U.S. wetlands (650–1460 g/m²/yr). Our results suggest that, in agricultural landscapes, land use intensity rather than landscape position – floodplain versus depression – drives wetland C sequestration and nutrient retention through increased sediment deposition.

Geomorphic; Landscape position; Nutrients; Sediment; Carbon; Nitrogen; Phosphorus; Land use; Agriculture; Erosion

• Vlček, P., Zavadil, V., & Gvoždík, V. (2020). The need for transboundary faunistics and conservation: first record of the Natterjack Toad (Epidalea calamita) in Czech Silesia, northeastern Czech Republic. Amphibian & Reptile Conservation, 14(3), 62-69.

The Natterjack Toad (Epidalea calamita) has been severely declining in the northern and eastern parts of its range in past decades. An immense population decline has been recorded in the Czech Republic, the southeastern edge of the species range. Contrary to the majority of published distribution range maps of the Natterjack Toad, it is present only in the western part of the Czech Republic (Bohemia), scattered among mostly isolated populations. A new, relatively distant population was recently discovered in the northeastern part of the country, in Czech Silesia. The genetic analysis presented here demonstrates that the new population belongs to the evolutionary lineage that is widely distributed in the northeastern part of the species range. Thus, this population is not a possible exotic introduction, but probably represents a natural extension of Natterjack Toad populations from Poland to the south. We urge conservation actions to be taken immediately to support this unique population, which is presently inhabiting a dump site. We further emphasize the necessity of considering distribution records on both sides of state borderlines when faunistic research is conducted in borderlands.

Amphibians, anthropogenic habitat, Bufonidae, Central Europe, distribution, edge populations, geographic range limit, phylogeography, range extension

Ke stažení

• Baxa, M., Šulcová, J., Kröpfelová, L., Pokorný, J., & Potužák, J. (2019). The quality of sediment in shallow water bodies – Long-term screening of sediment in Czech Republic. A new perspective of nutrients and organic matter recycling in agricultural landscapes. Ecological Engineering, 127, 151-159. doi:https://doi.org/10.1016/j.ecoleng.2018.11.009

The results of long-term screening of sediments from the Czech Republic from 2011 to 2017 are presented, more than 80% of the samples of which were taken from fishponds. The total sediment volume of Czech Republic fishponds is estimated to be 197 mil. m³. Quality of the sediment is impacted by numerous factors. Sediment may be used for land application, etc., as long as it abides with legislation limits. All results from our database, containing some 200 sites, have been compared with the Decree regulating the conditions for the application of sediments on agricultural land.

We have evaluated toxic metals (As, Pb, Zn, Cu, Hg, Cd), organic pollutants (C10–C40, BTEX, PAH, PCB, DDT) and nutrient volume. The assessment of results reveal the average concentrations of evaluated metals to have the following ranking: Zn > Cu > Pb > As > Cd > Hg. The most frequent excesses of the limit listed in Decree No. 257/2009 Sb. were reported for cadmium (21 sites, i.e. 13.2%). In the case of organic pollutants, the worst pollutant exceeded the limits for 7.2% of sites. DDT volume values were all below the threshold. The ratio between available nutrients and overall nutrient volume was: 0.5% P; 1.3% N; 48.1% Na; 20.4% Mg; 5.8% K; and 65.7% Ca.

Water ekosystém; Fishpond sediment; Toxic metals; Organic pollutants; Nutrients; Agricultural land

• Vinciková, H., Hanuš, J., & Pechar, L. (2015). Spectral reflectance is a reliable water-quality estimator for small, highly turbid wetlands. Wetlands Ecology and Management, 23(5), 933-946.

Spectral reflectance from water surfaces was measured in small (0.01–5 km2), turbid, eutrophic fishponds and mesotrophic quarry lakes in the Třeboň basin (South Bohemia, Czech Republic). A spectral scanner for direct field measurements from water surfaces and a hyperspectral airborne scanner were both used. The quarry lakes and fishponds differed in their spectral signature, which reflected the extent of their eutrophication. Their chlorophyll-a (chl-a) concentrations ranged from 2 to 455 µg/l−1. Various algorithms were tested to best fit the relationships between reflectance patterns and the water-quality parameters used—concentration of chl-a and the total amount of suspended solids. The reflectance ratios at 714 and 650 nm gave the best estimates for chl-a concentrations, and simple reflectance at near infrared wavelengths, especially at 806 nm, gave the best predictive values for total suspended solid evaluation (r 2 = 0.89). Field surface reflectance and airborne sensing measurements were well correlated; however, airborne reflectance data showed higher variability (r 2 = 0.93 and 0.86, respectively). The results support the validity of reflectance measurements, both field and airborne, as a rapid tool for evaluating water quality in many turbid and greatly disturbed, small water bodies.

Remote sensing; Water quality; Hyperspectral reflectance; Turbid inland waters; Chlorophyll; TSS