National Repository of Grey Literature 78 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
How climate change affects biotopes protected under Natura 2000 in southern Bohemia?
Vaškovský, Adam ; Křenová, Zdeňka (advisor) ; Trnka, Miroslav (referee)
Warnings of the intensity and widespread negative impacts of ongoing climate change are becoming more urgent. EU countries have created a unique network Natura 2000 to protect Europe's biodiversity and are legally obliged to protect the sites so that their conservation targets do not deteriorate. The key question is whether the static Natura 2000 system will continue to fulfil its purpose in the future, or whether climate change will lead to significant losses of European biodiversity. To date, there are still very few studies that address the modelling of climate change impacts on Natura 2000 sites. In this paper, using a new method combining climate envelope models with procedures applied to assess climate change risks to agroecosystems, I assessed the impact of climate change on eight selected natural habitat types (NHTs) occurring in south Bohemia. Agroclimatological indicators generated by the AgriClim model were used as predictors of the occurrence of suitable climate for NHTs. For modelling, I used three machine learning algorithms (generalized additive model, artificial neural network and random forest) and two ensemble learning techniques (averaging and stacking), of which I chose random forest as the most suitable for the resulting predictions. The modelling results show that for the...
Integrated national-scale assessment of climate change impacts on agriculture: the case of the Czech Republic
Arbelaez Gaviria, Juliana ; Boere, E. ; Havlík, P. ; Trnka, Miroslav
In recent years, investigating climate change impacts in the agricultural sector at the national level has become a priority for adaptation decision-making. Most of these studies quantify the impacts\nof biophysical effects and often ignore the cross-sectoral interactions and economic effects on relative competitiveness, international trade, global food supply, and food prices for the Czech Republic. Ignoring future productivity changes globally under climate change scenarios can underestimate or overestimate climate change impacts at the national level. Here, we use GLOBIOM-CZE, a global economic model, as part of a climate change impact assessment framework to evaluate the impacts on the Czech agricultural sector in terms of environmental and economic indicators. By comparing with the baseline, the ensemble of scenarios suggests a decrease in crop area and production while increasing grassland, positively affecting livestock production by mid-century. Corn and barley show the most adverse response in production and area, while rapeseed increases under scenario RCP 8.5 with CO2 fertilization effect. Livestock products production is projected to increase, especially bovine meat and milk, as within RCP 8.5, no constraints are placed on growing greenhouse gas emissions.
Short-term application of elevated temperature and drought influences the isotopic composition of winter wheat grains
Pernicová, Natálie ; Urban, Otmar ; Čáslavský, Josef ; Klem, Karel ; Trnka, Miroslav
The study aimed to determine the differences in carbon (δ13C) and nitrogen (δ15N) stable isotope ratios in grains of three winter wheat varieties grown under optimal and stress conditions. We found that the wheat variety has a significant effect on both δ13C and δ15N isotope ratios. Short-term (nine days) exposure to drought and high temperature during the heading or stem extension development phase significantly enhanced δ13C values, but only high temperature affected δ15N values. Enhanced δ15N values support the assumption that global warming causes a higher representation of the 15N isotope in plants. Moreover, significant interactive effects of temperature and water availability on the values of both isotopes were found implying that C and N metabolisms have been altered under the investigated stress conditions. We conclude that δ13C and δ15N isotope ratios of cereal grains are sensitive indicators of stress conditions, even short-term ones
Modelling the onset of phenological phases of spring barley (Hordeum vulgare L.)
Dížková, Petra ; Bartošová, Lenka ; Hájková, L. ; Balek, Jan ; Bláhová, Monika ; Bohuslav, Jakub ; Pohanková, Eva ; Trnka, Miroslav ; Žalud, Zdeněk
The onset of phenological phases of plant species is influenced mainly by air temperature. Each phenophase has its temperature limits (base temperature and temperature sum), which must be reached for each phase to occur. With knowledge of these limits, it is possible to predict the onset of phenological phases in localities where only meteorological data are available and also in future climate conditions. In this work, we used phenological ground-based data from 33 stations within the Czech Republic to calculate the most relevant meteorological predictors. PhenoClim software was used for phenological and meteorological data calibration and modelling. The smallest error that allows us to predict the term of the phenophases was found for the heading of spring barley (Hordeum vulgare L.), as the best predictor was the maximum daily temperature and the statistical error was 3.6 days.
Yield formation parameters of winter wheat under two CO2 levels in water sufficient and depleted environment
Hlaváčová, Marcela ; Klem, Karel ; Veselá, Barbora ; Findurová, Hana ; Hlavinka, Petr ; Smutná, P. ; Horáková, V. ; Škarpa, P. ; Trnka, Miroslav
Agricultural production faces with ongoing climate that in Europe takes form of changing seasonal precipitation pattern with more frequent drought spells. These changes come on top of rising air temperature and did and will affect productivity as well as onset and duration of key developmental stages for yield formation of major staple crops such as wheat. In order to ensure stable agricultural production and satisfy demand of the increasing humanpopulation, it is crucial to know responses of major field crops to these abiotic stress factors to assess suitability of genotypes to specific environmental conditions. The aim of this study was to evaluate final yield formation parameters of five winter wheat genotypes cultivated in pots and exposed to two different levels of CO2 concentrations (400 ppm as ambient and 700 ppm as elevated CO2 concentrations) and two water treatments (well- watered control and drought-stressed plants). Theexperimental treatments were set up in growth chambers from the end of heading stage (BBCH 59)to the beginning of ripening stage (BBCH 71) to simulate the conditions under future climate. The results showed that elevated CO2 concentration led to: (1) mitigation of reduction in final yield formation parameters of drought-stressed plants compared to those of control, (2) enhanced results of drought-stressed treatments compared to those of drought-stressed treatments exposed to the ambient CO2 concentration. Pannonia NS was found out as the less responsive genotype to the exposition of CO2 concentration (no statistically significant differences among ambient and elevated CO2 concentrations in all yield formation parameters were identified). On contrary, harvest index of genotype Bohemia was identified as the most sensitive parameter in response to drought stress as well as to the atmospheric CO2 concentration.
Comparing of observed and simulated field crop production in HERMES2Go model at Hněvčeves locality
Bohuslav, Jakub ; Kersebaum, Kurt Christian ; Madaras, M. ; Hlavinka, Petr ; Trnka, Miroslav ; Žalud, Zdeněk
The main objective of this study was calibration and testing of crop growth model \nHERMES2Go under long–term field experiment in Hněvčeves locality (coordinate 50°18´N, 15°43´E, \naltitude 265 m.a.s.l.). Observed data of yields and the other parameters like a weather data, soil \nparameters, management practice, phenology phases etc. monitored in last 38 years was used for model \ncalibration. Input parameters were available for 4 different fertilizer practices: i) control, ii) manure, iii) \nmineral fertilizer and iv) manure together with mineral fertilizer on each plot. Observed data are \navailable for yields of main and by–product and above ground biomass. The main grown crops were \nsugar beet, spring barley, winter wheat, silage maize, oat and alfalfa. Outputs of the model for main \nproduct are relatively accurate, but values of by–product requires additional calibration parameters \nsettings together with above–ground biomass.
Prevention of the occurrence and spread of natural fires in the immediate vicinity\nsurface sources of drinking water, including methods for estimating the consequences\npossible occurrence
Beranová, J. ; Čermák, Petr ; Albert, J. ; Cienciala, Emil ; Zatloukal, V. ; Kudláčková, Lucie ; Novotný, Jan ; Zeman, Evžen ; Kuráž, M. ; Vizina, Adam ; Trnka, Miroslav
The aim of the methodology is to create a pragmatic procedure for assessing the risks of the occurrence and spread of natural fires\nin the immediate vicinity of surface sources of drinking water. Methods for estimation are proposed in the methodology\nconsequences of the occurrence of natural fires on the quality of surface water, the prognosis of the change in the risk of fires\ndue to climate change and the procedure for determining the risk of secondary pollution of reservoirs due to\nchanges in runoff conditions after a natural fire. On this basis, the methodology designs and diversifies\npreventive and operational measures.
Estimate of carbon sequestration in the Czech Republic - afforestation of arable land, change of forest management, wetlands renaturations and tree lanes
Hruška, Jakub ; Pavelka, Marian ; Chuman, Tomáš ; Oulehle, Filip ; Vindušková, O. ; Cudlín, Pavel ; Trnka, Miroslav
Report acconunted quantitetivly as well qualitativly (for the year 2050) carbon sequestration for afforestation of arable land, change of forest management, wetlands renaturations and tree lanes.
Risk assessment and prediction of natural fires in the immediate vicinity\nsurface sources of drinking water.
Trnka, Miroslav ; Kudláčková, Lucie ; Čermák, P. ; Balek, Jan ; Novotný, Jan ; Homolová, Lucie ; Semerádová, Daniela ; Brovkina, Olga ; Štěpánek, Petr ; Zahradníček, Pavel ; Skalák, Petr ; Bláhová, Monika ; Benáček, Patrik ; Fischer, Milan ; Sedlák, Pavel ; Janouš, Dalibor ; Žalud, Zdeněk ; Marek, Michal V. ; Možný, M. ; Hájková, L. ; Chuchma, F. ; Knozová, G. ; Beranová, J. ; Zatloukal, V. ; Albert, J. ; Mašková, R. ; Cienciala, E. ; Vizina, A. ; Nesládková, M. ; Melišová, E. ; Hanel, M.
The methodology formulates a procedure for assessing the risks of the occurrence and spread of natural fires in the immediate vicinity of surface sources of drinking water. The methodology\nproposes methods for estimating the consequences of natural fires on surface water quality, forecasting the change in the risk of fires due to climate change and the procedure for determining the risk of secondary pollution of reservoirs due to changes in run off after a natural fire. On this basis, the methodology proposes and diversifies preventíve and operational measures.The measures were designed in connection to modeling results for the Hadce pilot síte near the Švihov reservoir and the experience with the adverse effects of extensive deforestation on the water quality in the Vranov and Vír reservoirs.
System of natural fire risk indicators (verification of various risk assessment procedures occurrence of natural fires) including instructions for the use of the integrated forecast system
Trnka, Miroslav ; Čermák, Petr ; Kudláčková, Lucie ; Balek, Jan ; Semerádová, Daniela ; Brovkina, Olga ; Zemek, František ; Štěpánek, Petr ; Zahradníček, Pavel ; Skalák, Petr ; Bláhová, Monika ; Jurečka, František ; Janouš, Dalibor ; Žalud, Zdeněk ; Marek, Michal V. ; Cienciala, Emil ; Beranová, J. ; Zatloukal, V. ; Albert, J. ; Tumajer, J. ; Možný, M. ; Hájková, L. ; Chuchma, F.
The presented methodology represents an improvement of the currently used system of wildfire monitoring and forecast. Based on extensive testing, it defines two fire weather indices. The method shows how the combination of both indices can lead to robust fire risk estimates. Both indices were uset to generate a forecast of fire weather, but also to quantify th erelationship between the frequency of favorable conditions for the occurrence of natural fires and their observed numbers, in several time steps (from 1 day to the entire season) The methodology has been implemented within the www. portal, where it serves as a tool for operational fire risk forecasting. The text of the methodology therefore contains instructions for using the menthodology therefore contains instructions for using the portal. Great attention is paid in the methodology to the aspect of climate change and estimating the impact of this phenomenon on the frequency of wildfires in the Czech republic.

National Repository of Grey Literature : 78 records found   1 - 10nextend  jump to record:
See also: similar author names
9 TRNKA, Michal
2 Trnka, M.
2 Trnka, Marián
2 Trnka, Martin
1 Trnka, Matyáš
9 Trnka, Michal
1 Trnka, Milan
1 Trnka, Milan Bc.
1 Trnka, Miroslav (absolvent PEF)
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