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Comparison of drought effect on young coppiced and standard individuals of sessile oak
Stojanović, Marko; Čater, M.; Pokorný, Radek
2016 - anglický
Assimilation and photosynthetic efficiency (quantum yield) of young oaks were compared in coppice and standard sessile oak stands of comparable age (100-120 years) under different light intensity categories. Measurements of assimilation response were performed during three consecutive growing seasons (2012, 2013 and 2014). In every category 8 young oaks of generative origin and same number of coppice sprouts of different stool were measured. The quantum yield in optimal conditions in standards was highest in the category A of closed canopy, while in coppices in category C. During severe drought in 2013 the drop in efficiency of standards was evident in all categories, while in coppices no differences in efficiency were confirmed between optimal and drought stress, proving the advantage of young coppices over standards.
Klíčová slova:
coppice; standards; photosynthetic response; quantum yield; light conditions; drought response
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Comparison of drought effect on young coppiced and standard individuals of sessile oak
Assimilation and photosynthetic efficiency (quantum yield) of young oaks were compared in coppice and standard sessile oak stands of comparable age (100-120 years) under different light intensity ...
Potential of the sentinel-2 red edge spectral bands for estimation of eco-physiological plant parameters
Malenovský, Zbyněk; Homolová, Lucie; Janoutová, Růžena; Landier, L.; Gastelluetchegorry, J-P.; Bertholt, B.; Huck, A.
2016 - anglický
In this study we investigated importance of the spaceborne instrument Sentinel-2 red edge spectral bands and reconstructed red edge position (REP) for retrieval of the three eco-physiological plant parameters, leaf and canopy chlorophyll content and leaf area index (LAI), in case of maize agricultural fields and beech and spruce forest stands. Sentinel-2 spectral bands and REP of the investigated vegetation canopies were simulated in the Discrete Anisotropic Radiative Transfer (DART) model. Their potential for estimation of the plant parameters was assessed through training support vector regressions (SVR) and examining their P-vector matrices indicatingsignificance of each input. The trained SVR were then applied on Sentinel-2 simulated images and the acquired\nestimates were cross-compared with results from high spatial resolution airborne retrievals. Results showed that contribution of REP was significant for canopy chlorophyll content, but less significant for leaf chlorophyll content and insignificant for leaf area index estimations. However, the red edge spectral bands contributed strongly to the retrievals of all parameters, especially canopy and leaf chlorophyll content. Application of SVR on Sentinel-2 simulated images demonstrated, in general, an overestimation of leaf chlorophyll content and an underestimation of LAI when compared to the reciprocal airborne estimates. In the follow-up investigation, we will apply the trained SVR algorithms on real Sentinel-2 multispectral images acquired during vegetation seasons 2015 and 2016.
Klíčová slova:
canopy chlorophyll; image acquisition; physiological models; high spatial resolution; vegetation cabioy; agricultural fields; leaf chlorophyll content; multispectral images; space-borne instruments; support vector regression (SVR); vegetation canopy
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Potential of the sentinel-2 red edge spectral bands for estimation of eco-physiological plant parameters
In this study we investigated importance of the spaceborne instrument Sentinel-2 red edge spectral bands and reconstructed red edge position (REP) for retrieval of the three eco-physiological plant ...
The usage of algae in biogas transformation
Paroulkova, P.; Sukačová, Kateřina; Murgasová, K.; Vítěz, T.; Chovanec, J.
2016 - anglický
Using of algae in a biogas transformation is still in the beginning. However, the microalgae have large potential from the perspective of growing demands on biogas quality and trend of using,natural resources. First of all, it is their ability to fix carbon dioxide (CO2) using photosynthesis and presumed ability of some algae to metabolize hydrogen sulphide (H2S). Biogas contains not only required methane but also components causing its worse quality such as mentioned CO2 and H2S. Therefore, the algae are potential biological systems for biogas-conditioning. The microalga Chlorella pyrenoidosa Chick (IPPAS C2) was used for fixation of CO2 and H2S in our experiment. The microalgae were cultivated in a medium BG 11. The algal suspension was aerated with the biogas during two weeks. Different values of CO2 concentration measured in the input and output confirmed decrease of CO2 caused by intensive growth of algal culture. Decline of H2S was not confirmed.
Klíčová slova:
biogas purification; carbon dioxide; methane; hydrogen sulphide; biological treatment
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The usage of algae in biogas transformation
Using of algae in a biogas transformation is still in the beginning. However, the microalgae have large potential from the perspective of growing demands on biogas quality and trend of using,natural ...
Flux footprints in different ecosystems
Macálková, Lenka; Havránková, Kateřina; Pavelka, Marian
2015 - anglický
Flux footprint is an upwind area where the atmospheric flux measured by an instrument is generated. Footprint size depends on measurement height, surface roughness, and atmospheric thermal stability. Our study focused on the flux footprints of four CzechGlobe ecosystem stations in a wetlands area, an agroecosystem, and young and mature spruce forests. Our aims were to prove that the sites were suitable for eddy covariance measurement and compare flux footprints under various atmospheric thermal conditions: stable, neutral, and unstable. Two computational models were used: the Kormann–Meixner (2001) and Kljun (2004)models. The outputs were processed graphically in site maps.
Klíčová slova:
eddy covariance; flux footprints; ecosystems
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Flux footprints in different ecosystems
Flux footprint is an upwind area where the atmospheric flux measured by an instrument is generated. Footprint size depends on measurement height, surface roughness, and atmospheric thermal stability. ...
Summer fluxes of nitrous oxide from boreal forest
Macháčová, Kateřina; Pihlatie, M.; Halmeenmäki, E.; Pavelka, Marian; Dušek, Jiří; Bäck, J.; Urban, Otmar
2015 - anglický
Boreal forests cover almost one-third of the global forest area, and results of soil measurements show them to be a natural source of the important greenhouse gas nitrous oxide (N2O). Nevertheless, N2O fluxes from boreal tree species have been excluded from calculations of N2O exchanges from forest ecosystems. Therefore, our objective was to quantify and scale up the N2O fluxes from stems of mature silver birch (Betula pendula), Scots pine (Pinus sylvestris), and Norway spruce (Picea abies), as well as from the forest floor of a boreal forest in Finland during June and July 2014. This study shows that boreal tree species emit N2O from their stems under natural field conditions and significantly contribute up to 8% of forest floor fluxes of N2O. Spruce trees seem to be the strongest N2O emitter among the studied tree species. Moreover, the N2O flux rates from both coniferous tree species increased with decreasing soil water content. This study highlights the necessity to include N2O fluxes from trees within the total greenhouse gas budget of forest ecosystems.
Klíčová slova:
boreal forest; greenhouse gases; forest ecosystem; Picea abies; Pinus Silvestris
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Summer fluxes of nitrous oxide from boreal forest
Boreal forests cover almost one-third of the global forest area, and results of soil measurements show them to be a natural source of the important greenhouse gas nitrous oxide (N2O). Nevertheless, ...
Interactive effects of UV radiation and drought on the accumulation of flavonols in selected herbs and grass in a mountain grassland ecosystem
Veselá, Barbora; Surá, Kateřina; Rajsnerová, Petra; Klem, Karel; Holub, Petr; Urban, Otmar
2015 - anglický
The main objective of this 4-year experiment conducted in a mountain grassland ecosystem was to investigate the interactive effects of ultraviolet (UV) treatment and drought on changes in accumulation of UV-screening compounds (flavonols) in selected herbs (Hypericum maculatum Crantz, Rumex obtusifolius L.) and grass (Agrostis tenuis Sibth.). Inasmuch as drought and UV radiation induce similar protective mechanisms, we tested the hypothesis that UV radiation and drought elicit synergistic effects on flavonol accumulation. The experimental plots were manipulated using rainout shelters enabling the exclusion and transmission of incident precipitation and UV radiation. Generally, UV and drought treatments had similar effects on flavonol accumulation. For R. obtusifolius, UV exclusion resulted in a substantial reduction of UV-screening compounds, particularly under ambient precipitation conditions, while for H. maculatum and A. tenuis UV exclusion caused only a slight reduction of flavonol content. Similarly, the drought treatment caused an increase in flavonol accumulation.
Klíčová slova:
uv radiation; grassland ecosystem; herbs and grass
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Interactive effects of UV radiation and drought on the accumulation of flavonols in selected herbs and grass in a mountain grassland ecosystem
The main objective of this 4-year experiment conducted in a mountain grassland ecosystem was to investigate the interactive effects of ultraviolet (UV) treatment and drought on changes in ...
Elevated temperature stimulates light-induced processes that contribute to protecting photosystem II against oxidative stress
Materová, Z.; Štroch, Michal; Holubová, I.; Sestřenková, J.; Oravec, Michal; Večeřová, Kristýna; Špunda, Vladimír
2015 - anglický
We focused on elucidating the impact of elevated temperature on rapid induction of zeaxanthin (Z)- dependent photoprotection in two different plant species. The dynamics of violaxanthin (V) de-epoxidation under different illumination regimes was studied together with chlorophyll a fluorescence transients in Picea abies seedlings and Arabidopsis thaliana leaves pre-acclimated to temperatures ranging from 20 to 40°C. Whereas for spruce seedlings the rapid phase of V de-epoxidation (induced by either 10 s illumination or 10 light pulses 1 s in duration at 1 min intervals) was gradually stimulated upon increasing temperatures, for A. thaliana leaves considerable acceleration of V de-epoxidation occurred only at 40°C. Moreover, only for spruce seedlings was a considerable amount of Z accumulated after 10 × 1 s illumination. Elevated temperatures stimulated rapid formation of Z-dependent non-radiative dissipation of excitation energy within photosystem II (NRD) induced by 1 s light pulses only for spruce seedlings. The possible role of a specific fatty acid composition in spruce thylakoid membrane lipids in facilitated V de-epoxidation and NRD induction at elevated temperatures is discussed.
Klíčová slova:
plant species; Picea abies; temperatures ranging
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Elevated temperature stimulates light-induced processes that contribute to protecting photosystem II against oxidative stress
We focused on elucidating the impact of elevated temperature on rapid induction of zeaxanthin (Z)- dependent photoprotection in two different plant species. The dynamics of violaxanthin (V) ...
Comparison of forestry reclamation and spontaneous succession from plant diversity, production, and economic perspectives
Cudlín, Ondřej; Faigl, T.; Plch, Radek; Cudlín, Pavel
2015 - anglický
The aim of our study was to determine whether the values of plant community diversity, the volume of wood, and the partial economic efficiency of plots left to spontaneous succession have yet reached similar values as those recorded on forestry reclaimed plots. Six forestry reclaimed plots and six plots with spontaneous succession were established at the Great Podkrušnohorská spoil heap and selected tree biometric characteristics were measured. Plots’ economic efficiency was calculated as the difference between the costs to level the spoil heap as well as establish and manage the forest reclamation and the theoretical profit from wood. The numbers of tree species, numbers of individuals, wood volume, and Simpson diversity index values did not differ significantly between plots with spontaneous succession and reclaimed plots. The economic efficiencies of both types of plots were too burdened with high initial investments for levelling, which can theoretically be returned within 300 years for reclamation plots and 180 years for succession plots. According to our results and those of some other authors, values for diversity and wood production are similar or higher on plots resulting from spontaneous succession in comparison to values on reclaimed plots. For this reason, both types of management should be used to establish a new suitable mosaic of ecosystems in the post-mining landscape.
Klíčová slova:
forestry reclamation; trees; plant diversity; production and economic perspectives
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Comparison of forestry reclamation and spontaneous succession from plant diversity, production, and economic perspectives
The aim of our study was to determine whether the values of plant community diversity, the volume of wood, and the partial economic efficiency of plots left to spontaneous succession have yet reached ...
Testing a statistical forecasting model of electric energy consumption for two regions in the Czech Republic
Rajdl, Kamil; Farda, Aleš; Štěpánek, Petr; Zahradníček, Pavel
2015 - anglický
Precise forecasting of electric energy consumption is of great importance for the electric power industry. It helps system operators optimally schedule and control power systems, and even slight improvements in prediction accuracy might yield large savings or profits. For these reasons, many forecasting models based on various principles have been developed and studied. Because of energy consumption’s strong dependence on weather conditions, such models often utilize outputs from numerical weather prediction models. In this study, we present and analyse a statistical model for forecasting hourly electrical energy consumption by customers of E.ON Energie, a.s. in two regions of the Czech Republic. The aim of this model is to create hourly predictions up to several days in advance. The model uses hourly data of consumed energy from 2011–2014 and corresponding predictions of temperature and cloudiness provided by the ALADIN/ CZ model. The statistical model is based on a regression analysis applied to appropriate data samples and supplemented by several optional post-processing methods. Specifically, we use a robust linear regression algorithm to identify energy consumption’s dependence on temperature, the meteorological variable with the largest influence on consumption. Our post-processing methods focused on removing prediction bias resulting from economic situations (represented by the goss domestic product, GDP) and sudden temperature changes. We analysed the presented model from the point of view of the hourly predictions’ accuracy for 2013 and 2014. Accuracy was primarily measured by mean absolute error. It was evaluated for individual months, and the effects of individual parts of the model on accuracy value are shown. Introduction
Klíčová slova:
forecasting model; electric energy; Czech Republic
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Testing a statistical forecasting model of electric energy consumption for two regions in the Czech Republic
Precise forecasting of electric energy consumption is of great importance for the electric power industry. It helps system operators optimally schedule and control power systems, and even slight ...
Exploring beliefs about climate change and attitudes towards adaptation among Czech citizens
Lorencová, Eliška; Vačkář, David
2015 - anglický
Climate change currently represents one of the major global environmental problems. In order to respond to these changes, adaptation actions at all levels, from national to local, need to be undertaken (European Commission 2013). Moreover, perceptions of climate change are an important element affecting actual attitudes towards adaptation actions and influencing policy and communication regarding climate change (Lorenzoni et al. 2005). This paper presents the results of a survey on perceptions of climate change, including beliefs about climate change and attitudes towards adaptation, conducted among 1,024 Czech citizens in October 2014. Survey results show that the majority of respondents (78%) agreed with the statement that global climate change is happening. Positive responses about perceptions of climate change were found especially among younger people (18 to 34 years of age). In terms of adaptation measures, 51% of respondents had adopted a variety of individual actions (ranging from water savings to property insurance), discussed in the paper in further detail. Older people (≥ 45 years of age) with higher education preferred rather technical adaptation measures (e.g. flood protection for property, installation of rainwater reservoirs, etc.). The survey represents unique insights into attitudes towards climate change within the Czech Republic which had not previously been investigated to this extent. The results provided can support decision-making regarding adaptation policy, individual adaptation actions, and communication of climate change issues towards general public. Introduction
Klíčová slova:
climate change; global environmental problems; Czech Republic
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Exploring beliefs about climate change and attitudes towards adaptation among Czech citizens
Climate change currently represents one of the major global environmental problems. In order to respond to these changes, adaptation actions at all levels, from national to local, need to be ...
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