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Effect of elevated CO2 on morphological and photosynthetic parameters in two understory grass species in Beskydy Mountains
Holub, Petr; Klem, Karel; Urban, Otmar
2017 - anglický
We transplanted two grass species, Calamagrostis arundinacea and Luzula sylvatica, to the understory of\na 10-year-old experimental mixed forest exposed to ambient (385 μmol CO2 mol–1, AC) and elevated (700\nμmol CO2 mol–1, EC) atmospheric CO2 concentration using a glass dome facility. Effects of EC on plant\nmorphology and photosynthesis were examined after three years of treatment. We tested the hypotheses\nthat shade-tolerant species can profit from EC even at low light conditions and that relatively low accumulation\nof assimilates at such light conditions will not cause CO2-induced down-regulation of photosynthesis.\nWe expected that EC can substitute insufficient light intensities under the tree canopy and lead to both\nhigher biomass production and survival of plants in deep forest understories. The typical shade-tolerant\nspecies L. sylvatica exhibited positive acclimation under EC allowing higher light use efficiency under subsaturating\nlight intensities as compared to plants grown under AC. In contrast, C. arundinacea showed\nhigher stimulation of growth and photosynthetic rates by EC mainly under saturating light intensities at\nthe beginning of the growing season, when the forest leaf area is not fully developed and the open canopy\nallows a greater proportion of incident light to reach the understory. Our data indicate that growth and\nphysiological responses of EC plants in forest understories are species specific, differ from responses of\nsun-exposed plants, and depend on degree of shading.
Klíčová slova:
Effect of elevated CO2; photosynthetic parametrs; Beskydy mountains
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Effect of elevated CO2 on morphological and photosynthetic parameters in two understory grass species in Beskydy Mountains
We transplanted two grass species, Calamagrostis arundinacea and Luzula sylvatica, to the understory of\na 10-year-old experimental mixed forest exposed to ambient (385 μmol CO2 mol–1, AC) and ...
Towards a combining of remote sensing and in situ evapotranspiration measurements
Fischer, Milan; Jurečka, František; Anderson, M.; Hain, C.; Pozníková, Gabriela; Hlavinka, Petr; Orság, Matěj; Lukas, V.; Žalud, Z.; Trnka, Miroslav
2017 - anglický
This study provides preliminary results from combining in situ Bowen ratio energy balance (BREB) and\nevapotranspiration (ET) measurements techniques with physically based remote sensing ET estimates determined\nby the Atmosphere-Land Exchange Inverse (ALEXI) model. Evapotranspiration measurements\nand ALEXI estimates were analysed in an agricultural area close to Polkovice, Czech Republic during 2015,\nwhen a drought spell and intensive heatwaves appeared in the country. The BREB system was monitoring a\nwinter wheat (Triticum aestivum L.) field (~26 ha) while the ALEXI pixel (~5 km resolution) covered a wide\nrange of crops, including mainly winter wheat, spring barley, and winter rape. The study results showed that,\nalthough the applied methods work at different spatial scales (field vs. landscape), their combination can provide\nfurther insights into ET at both scales. For instance, such approach can be used to identify whether a specific\necosystem investigated in situ contributes to cooling or warming of the landscape.
Klíčová slova:
remote sensing; evapotranspiration; Bowen ratio energy balance
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Towards a combining of remote sensing and in situ evapotranspiration measurements
This study provides preliminary results from combining in situ Bowen ratio energy balance (BREB) and\nevapotranspiration (ET) measurements techniques with physically based remote sensing ET estimates ...
Forest regeneration within the treeline ecotone in the Giant Mountains under climate change
Cudlín, Ondřej; Chumanová-Vávrová, Eva; Edwards-Jonášová, Magda; Heřman, Michal; Štěpánek, Petr; Cudlín, Pavel
2017 - anglický
Natural regeneration of mountain spruce forests began in the Giant Mountains 25 years ago after a reduction\nof severe and long-enduring air pollution. This process has been influenced by climatic change.\nThe aim of our contribution was to present background data for the potential elevational shift of spruce\nregeneration under conditions of climate change. These upslope shifts may also depend on constraints\nsuch as climate extremes, unfavourable soil conditions, absence of ectomycorrhizal symbionts, and lack of\nmicrosites suitable for seedlings. Since 2014, we have studied the main driving factors affecting Norway\nspruce regeneration, and in particular soil conditions, ectomycorrhizal symbionts, ground vegetation cover,\nand forest health, in six transects across the treeline ecotone located on a NW-to-NE transect through\nthe Giant Mountains. Microclimatic measurements showed that the mean difference in growing season\ntemperature between the montane spruce forests and forests at the treeline was −0.54°C. The model\nHADGEM2 predicted that in 20 years the temperature at the treeline will be similar to the current one at\nmontane elevations. The difference in prevailing soil types between the montane spruce forests and forests\nat the current treeline (i.e. podzol vs. ranker type) could be an important factor limiting success of the\nupslope spreading of spruce. Furthermore, areas covered by microsites favourable for natural spruce regeneration,\nespecially spruce litter patches, decaying wood, mosses, and Avenella flexuosa stands, were\nshown to decrease with increasing elevation. It is likely that spruce will move upslope in response to climate\nchange, but the process is likely to be slow or even blocked for some periods, especially by unfavourable\nsoil conditions and climatic extremes.
Klíčová slova:
forest regeneration; Giant mountains; climate change
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Forest regeneration within the treeline ecotone in the Giant Mountains under climate change
Natural regeneration of mountain spruce forests began in the Giant Mountains 25 years ago after a reduction\nof severe and long-enduring air pollution. This process has been influenced by climatic ...
Approaching dangerous impacts of global climate change
Ač, Alexander
2017 - anglický
Current global policy efforts are focused on limiting the global rise in mean temperature to well below a 2 K\nwarming compared to the pre-industrial temperature. It is questionable if achieving such goal is still feasible.\nHere, I review published works that suggesting that to keep global warming below or at a 2 K level cannot\nbe considered as safe, as is often assumed. A large body of studies have emerged recently investigating\nthe impacts of global climate change (GCC) at a 1.5 K or 2 K warming. The impacts range from changes in\nthe hydrological cycle, increasing frequency and intensity of extreme weather events, triggering of change\nfeedback processes at various spatio-temporal scales, affecting biological processes from the molecular to\necosystem levels, and to disrupting socio-economic conditions. In this short review, I present the latest scientific\nknowledge regarding some of the most important impacts of GCC on natural ecosystems, humanmade\nsystems, and societies.
Klíčová slova:
global climate change
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Approaching dangerous impacts of global climate change
Current global policy efforts are focused on limiting the global rise in mean temperature to well below a 2 K\nwarming compared to the pre-industrial temperature. It is questionable if achieving such ...
Drought monitor for the Czech Republic-www.intersucho.cz
Trnka, Miroslav; Hlavinka, Petr; Semerádová, Daniela; Balek, Jan; Možný, M.; Štěpánek, Petr; Zahradníček, Pavel; Hayes, M.; Eitzinger, Josef; Žalud, Zdeněk
2016 - anglický
Because drought and its impacts are among the worst hydrometeorological extremes (including also Central European conditions), the aim of this paper is to describe the core and use of the Integrated drought monitoring system for the Czech Republic. Land-use, information about soil, vegetation characteristics and meteorological data are used as inputs to validated water balance SoilClim model, which is applied for estimates of actual and reference evapotranspiration and water saturation of the soil profile in % or soil moisture content in mm. Moreover the prognosis of expected soil moisture (based on probabilistic analysis) is calculated for next 1, 2, 4 and 8 weeks. Main results are weekly updated in form of drought occurrence maps, which are published in spatial resolution 500 m for whole territory of the Czech Republic and for all its 76 districts separately. Final maps with detail comments are available at drought topic dedicated web page (ANONYM 3 2014).
Klíčová slova:
model; soil moisture; land use; evapotranspiration; drought assessment
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Drought monitor for the Czech Republic-www.intersucho.cz
Because drought and its impacts are among the worst hydrometeorological extremes (including also Central European conditions), the aim of this paper is to describe the core and use of the Integrated ...
Drought periods in 2014
Zahradníček, Pavel; Trnka, Miroslav; Štěpánek, Petr; Semerádová, Daniela; Farda, Aleš
2016 - anglický
The first half of year 2014 was characterized by the occurrence of extreme weather. Episode without precipitation were alternated with thunderstorms, temperature were mostly above normal and was occurred first heat wave. The year began with a very mild winter, when amount of snow was only 27% of long term average and in agricultural region South Moravia only about 10%. The winter temperature was more than 2 degrees C higher than normal. March and April were characterized by low sum of precipitation mainly again in South Moravia, both months were about 70% of long term average. March and April temperature were significantly above normal (March about more than about 4 degrees C and April more than 2 degrees C). In contrast May was cold and rainy. In the middle of the month there were persistent rainfall, which caused an increase of river levels and flooding several areas. June was again very dry. These weather conditions led to the strong dry episodes during first half of the year.
Klíčová slova:
data quality-control; model; drought; Czech Republic; year 2014; precipitation; temperature
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Drought periods in 2014
The first half of year 2014 was characterized by the occurrence of extreme weather. Episode without precipitation were alternated with thunderstorms, temperature were mostly above normal and was ...
Physiological equivalent temperature as an indicator of the UHI effect with the city of Prague as an example
Zahradníček, Pavel; Žák, M.; Skalák, Petr
2016 - anglický
Description of an Urban Heat Island (UHI) using the difference in air temperature is one of the world's most studied characteristics. If, however, one wants to express how the temperature is perceived by humans, one must consider the overall effect of air temperature, wind speed, air humidity and radiation flows, which is expressed using temperature bioclimatological indexes. One of them is the socalled physiological equivalent temperature (PET), which is used for quantification of the overall effect of meteorological parameters combined with human energetic balance and which is perceived by humans. The RayMan (MATZARAKIS et al. 2007, 2010) microscale models in the city of Prague were used to simulate biometeorological conditions describing the effect on humans using PET.
Klíčová slova:
model; physiological equivalent temperature; uhi; RayMan; Prague
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Physiological equivalent temperature as an indicator of the UHI effect with the city of Prague as an example
Description of an Urban Heat Island (UHI) using the difference in air temperature is one of the world's most studied characteristics. If, however, one wants to express how the temperature is perceived ...
WINTER RECREATION AND SNOW
Zahradníček, Pavel; Rožnovský, J.; Štěpánek, Petr; Farda, Aleš; Brzezina, J.
2016 - anglický
Climate assessment should not be limited to just statistical analysis, but also look at relationships in data and its uses in other areas of everyday life. One such area is tourism and recreation, which is also to a great extent influenced by the weather. This paper focuses on the winter season and the related possibilities for tourism. One of the key factors is snow conditions of the particular place. This analysis takes into account the amount of new snow and maximum snow depth and changes in these parameters as a result of the current global climate change. Especially in the last 15 years, years with less snow are more frequent and this is especially seen at highest altitudes of the country. The study also analyzed outputs of climate models with regards to winter season, including calculations of the number of melting days.
Klíčová slova:
new snow; total snow depth; climate change; climate models
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
WINTER RECREATION AND SNOW
Climate assessment should not be limited to just statistical analysis, but also look at relationships in data and its uses in other areas of everyday life. One such area is tourism and recreation, ...
Application of DSSAT model to simulated thermophilic crops in central and southern Europe
Potop, V.; Mateescu, C.D.; Türkott, L.; Zahradníček, Pavel; Boroneant, C.; Constantinescu, F.; Iamandei, M.
2016 - anglický
This study presents applications of DSSAT version 4.5 software package to simulate thermophilic crops. The results are used to identified adaptation options to reduce impacts of climate changes, pest and diseases in thermophilic crops in the central and southeastern Europe, specifically in Elbe River lowland and Romania. For the Czech Republic, experimental research at farm level includes: (1) testing thermophilic assortment of vegetables in Elbe lowland conditions; (2) monitoring the meteorological data, phenological phases, soil characteristics, leaf area and the amount of aboveground biomass on farmer vegetable fields. For Romania, the focus is put on crop water use efficiency under current and future climate scenarios for thermophilic species (maize) in different agricultural sites from south and south-eastern regions. CERES Maize and CROPGRO-vegetables modules embedded in DSSAT were used.
Klíčová slova:
CERES Maize; CROPGRO-tomato; plant protection; climate change
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Application of DSSAT model to simulated thermophilic crops in central and southern Europe
This study presents applications of DSSAT version 4.5 software package to simulate thermophilic crops. The results are used to identified adaptation options to reduce impacts of climate changes, pest ...
Detection of drought events using combination of satellite data and soil moisture modelling
Semerádová, Daniela; Trnka, Miroslav; Hlavinka, Petr; Balek, Jan; Bohovič, Roman; Tadesse, T.; Hayes, M.; Wardlow, B.; Žalud, Zdeněk
2016 - anglický
The use of satellite data offers a potentially well usable tool to accurate drought monitoring. The study examines the space-time possibility of agricultural drought detection using freely available data from the MODIS instrument onboard Terra and Aqua satellites that reflects vegetation condition. Vegetation greenness metrics used in this study are based on the spectral reflectance curves in the visible red and near-infrared part of the spectrum and are expressed in relation to the average for the period of 2000-2014. The results are presented in weekly time step for the whole area of the Czech Republic, and are compared to the drought monitor system, based on the SoilClim dynamic model for soil water content estimates. These data, as well as other parameters, such as soil properties and land use, are integrated at 500 meters spatial resolution.
Klíčová slova:
vegetation; modis; products; drought monitor; remote sensing; modis; ndvi; seasonal greenness
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Detection of drought events using combination of satellite data and soil moisture modelling
The use of satellite data offers a potentially well usable tool to accurate drought monitoring. The study examines the space-time possibility of agricultural drought detection using freely available ...
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