Global Change Research Center

Brno, Czech Republic

Global Change Research Center

Brno, Czech Republic
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Guidolotti G.,University of Tuscia | Rey A.,Spanish Scientific Council CSIC | D'andrea E.,CNR Institute of Agro-environmental and Forest Biology | Matteucci G.,National Research Council Italy | And 2 more authors.
Tree Physiology | Year: 2013

The temporal variability of ecosystem respiration (RECO) has been reported to have important effects on the temporal variability of net ecosystem exchange, the net amount of carbon exchanged between an ecosystem and the atmosphere. However, our understanding of ecosystem respiration is rather limited compared with photosynthesis or gross primary productivity, particularly in Mediterranean montane ecosystems. In order to investigate how environmental variables and forest structure (tree classes) affect different respiration components and RECO in a Mediterranean beech forest, we measured soil, stem and leaf CO2 efflux rates with dynamic chambers and R ECO by the eddy-covariance technique over 1 year (2007-2008). Ecosystem respiration showed marked seasonal variation, with the highest rates in spring and autumn and the lowest in summer. We found that the soil respiration (SR) was mainly controlled by soil water content below a threshold value of 0.2 m3 m-3, above which the soil temperature explained temporal variation in SR. Stem CO2 effluxes were influenced by air temperature and difference between tree classes with higher rates measured in dominant trees than in co-dominant ones. Leaf respiration (LR) varied significantly between the two canopy layers considered. Non-structural carbohydrates were a very good predictor of LR variability. We used these measurements to scale up respiration components to ecosystem respiration for the whole canopy and obtained cumulative amounts of carbon losses over the year. Based on the up-scaled chamber measurements, the relative contributions of soil, stem and leaves to the total annual CO2 efflux were: 56, 8 and 36%, respectively. These results confirm that SR is the main contributor of ecosystem respiration and provided an insight on the driving factors of respiration in Mediterranean montane beech forests. © 2013 The Author 2013.

Pavela R.,Czech Republic Crop Research Institute | Zabka M.,Czech Republic Crop Research Institute | Bednar J.,Global Change Research Center | Triska J.,Global Change Research Center | Vrchotova N.,Global Change Research Center
Industrial Crops and Products | Year: 2016

Fennel is an important medicinal and aromatic plant. Essential oils obtained from this plant have found application in various fields, including the production of botanical insecticides. In two seasons, we evaluated the yields of seeds and above-ground biomass, and we monitored the yield rate, chemical composition and insecticidal efficacy of the EOs.We found out that the tested genotype provided a high biomass yield, with two harvests per year; the yield of fresh above-ground biomass was 15.8kg/m2 in the first year, and 14.3kg/m2 in the second year, or 3.3kg/m2 and 3.1kg/m2, respectively, of dry biomass. This biomass could be used to potentially obtain 366.2kg and 317.4kg of EO/ha, respectively, in the first and second year, i.e. an amount statistically significantly higher compared to EOs obtained from seeds (215.3kg and 187.9kg of EO/ha, respectively, for the first and second year).Their analysis detected 7-9 substances (relative contents >0.05%), forming 88.99-98.59% of the EO contents. All EOs contained a majority share of trans-anethole (48.42-63.23%). The highest amount of trans-anethole was found in EOs obtained from seeds (≥60%).All EOs obtained from different biomasses exhibited important insecticidal effects against Culex quinquefasciatus larvae, Spodoptera littoralis larvae and Musca domestica adults.Czech fennel F. vulgare cv. Moravsky is a high-growth genotype that provides a high yield of above-ground biomass; this biomass can be used with a benefit to obtain EOs utilizable for the development and production of botanical insecticides. © 2016 Elsevier B.V.

Audsley E.,Cranfield University | Trnka M.,Mendel University in Brno | Trnka M.,Global Change Research Center | Sabate S.,Autonomous University of Barcelona | And 7 more authors.
Climatic Change | Year: 2014

Studies of climate change impacts on agricultural land use generally consider sets of climates combined with fixed socio-economic scenarios, making it impossible to compare the impact of specific factors within these scenario sets. Analysis of the impact of specific scenario factors is extremely difficult due to prohibitively long run-times of the complex models. This study produces and combines metamodels of crop and forest yields and farm profit, derived from previously developed very complex models, to enable prediction of European land use under any set of climate and socio-economic data. Land use is predicted based on the profitability of the alternatives on every soil within every 10’ grid across the EU. A clustering procedure reduces 23,871 grids with 20+ soils per grid to 6,714 clusters of common soil and climate. Combined these reduce runtime 100 thousand-fold. Profit thresholds define land as intensive agriculture (arable or grassland), extensive agriculture or managed forest, or finally unmanaged forest or abandoned land. The demand for food as a function of population, imports, food preferences and bioenergy, is a production constraint, as is irrigation water available. An iteration adjusts prices to meet these constraints. A range of measures are derived at 10’ grid-level such as diversity as well as overall EU production. There are many ways to utilise this ability to do rapid What-If analysis of both impact and adaptations. The paper illustrates using two of the 5 different GCMs (CSMK3, HADGEM with contrasting precipitation and temperature) and two of the 4 different socio-economic scenarios (“We are the world”, “Should I stay or should I go” which have contrasting demands for land), exploring these using two of the 13 scenario parameters (crop breeding for yield and population). In the first scenario, population can be increased by a large amount showing that food security is far from vulnerable. In the second scenario increasing crop yield shows that it improves the food security problem. © 2014, Springer Science+Business Media Dordrecht.

Ameixa O.M.C.C.,Global Change Research Center | Messelink G.J.,Wageningen UR Greenhouse Horticulture | Kindlmann P.,Global Change Research Center | Kindlmann P.,Charles University
PLoS ONE | Year: 2013

Since typically there are many predators feeding on most herbivores in natural communities, understanding multiple predator effects is critical for both community and applied ecology. Experiments of multiple predator effects on prey populations are extremely demanding, as the number of treatments and the amount of labour associated with these experiments increases exponentially with the number of species in question. Therefore, researchers tend to vary only presence/absence of the species and use only one (supposedly realistic) combination of their numbers in experiments. However, nonlinearities in density dependence, functional responses, interactions between natural enemies etc. are typical for such systems, and nonlinear models of population dynamics generally predict qualitatively different results, if initial absolute densities of the species studied differ, even if their relative densities are maintained. Therefore, testing combinations of natural enemies without varying their densities may not be sufficient. Here we test this prediction experimentally. We show that the population dynamics of a system consisting of 2 natural enemies (aphid predator Adalia bipunctata (L.), and aphid parasitoid, Aphidius colemani Viereck) and their shared prey (peach aphid, Myzus persicae Sulzer) are strongly affected by the absolute initial densities of the species in question. Even if their relative densities are kept constant, the natural enemy species or combination thereof that most effectively suppresses the prey may depend on the absolute initial densities used in the experiment. Future empirical studies of multiple predator - one prey interactions should therefore use a two-dimensional array of initial densities of the studied species. Varying only combinations of natural enemies without varying their densities is not sufficient and can lead to misleading results. © 2013 Ameixa et al.

Brazdil R.,Masaryk University | Brazdil R.,Global Change Research Center | Dobrovolny P.,Masaryk University | Dobrovolny P.,Global Change Research Center | And 10 more authors.
Climate of the Past | Year: 2013

This paper addresses droughts in the Czech Lands in the 1090-2012 AD period, basing its findings on documentary evidence and instrumental records. Various documentary sources were employed for the selection of drought events, which were then interpreted at a monthly level. Whi. © Author(s) 2013.

Urban O.,Global Change Research Center | Hrstka M.,Brno University of Technology | Zitova M.,Global Change Research Center | Holisova P.,Global Change Research Center | And 7 more authors.
Plant Physiology and Biochemistry | Year: 2012

While downward photosynthetic acclimation in response to elevated CO2 (EC) is frequently accompanied by reduction in Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), the exact mechanism behind this decrease and its dynamics are not well understood. We comprehensively studied Rubisco adjustment to EC in coniferous Picea abies using an electrophoretic (protein content), spectrophotometric (initial (RAinitial) and total (RAtotal) in vitro Rubisco activities), and gas-exchange (maximum carboxylation activity in vivo (VCmax)) techniques. With respect to differing carbon sink strength and nitrogen remobilization, we hypothesized greater acclimation of photosynthesis in one-year-old as compared to current-year needles and at the end than at the beginning of the vegetation season. EC treatment led to a decrease in VCmax values in current-year needles, but the ribulose-1,5-bisphosphate (RuBP)-limited rate of photosynthesis (Jmax) remained unaffected. Indeed, both VCmax and Jmax were reduced by the EC treatment in one-year-old needles. The extent of photosynthetic acclimation in EC plants did not increase, however, during the vegetation season. EC decreased the activation state of Rubisco (RAinitial/RAtotal) by 16% and 5% in current-year and one-year-old needles, respectively (averaged over the growing season). While during spring (short-term effect) EC treatment did not influence the Rubisco content per unit leaf area and decreased its specific activity (activity per unit Rubisco mass) in both needle age classes studied, exposure to EC during the entire vegetation season tended to reduce the Rubisco content while increasing its specific activity. Irrespective of CO2 treatment and needle age, a hyperbolic-decay relationship was observed between Rubisco-specific activity and its content. © 2012 Elsevier Masson SAS.

Guidolotti G.,CNR Institute of Agro-environmental and Forest Biology | Salviato M.,University of Padua | Calfapietra C.,CNR Institute of Agro-environmental and Forest Biology | Calfapietra C.,Global Change Research Center
Environmental Science and Pollution Research | Year: 2016

There is a growing interest to identify and quantify the benefits provided by the presence of trees in urban environment in order to improve the environmental quality in cities. However, the evaluation and estimate of plant efficiency in removing atmospheric pollutants is rather complicated, because of the high number of factors involved and the difficulty of estimating the effect of the interactions between the different components. In this study, the EMEP MSC-W model was implemented to scale-down to tree-level and allows its application to an industrial-urban green area in Northern Italy. Moreover, the annual outputs were compared with the outputs of UFORE (nowadays i-Tree), a leading model for urban forest applications. Although, EMEP/MSC-W model and UFORE are semi-empirical models designed for different applications, the comparison, based on O3, NO2 and PM10 removal, showed a good agreement in the estimates and highlights how the down-scaling methodology presented in this study may have significant opportunities for further developments. © 2016 Springer-Verlag Berlin Heidelberg

Calfapietra C.,CNR Institute of Agro-environmental and Forest Biology | Calfapietra C.,Global Change Research Center | Fares S.,Italian Agricultural Research Council | Manes F.,University of Rome La Sapienza | And 4 more authors.
Environmental Pollution | Year: 2013

Biogenic Volatile Organic Compounds (BVOC) play a critical role in biosphere-atmosphere interactions and are key factors of the physical and chemical properties of the atmosphere and climate. However, few studies have been carried out at urban level to investigate the interactions between BVOC emissions and ozone (O3) concentration. The contribution of urban vegetation to the load of BVOCs in the air and the interactions between biogenic emissions and urban pollution, including the likely formation of O3, needs to be investigated, but also the effects of O3 on the biochemical reactions and physiological conditions leading to BVOC emissions are largely unknown. The effect of BVOC emission on the O3 uptake by the trees is further complicating the interactions BVOC-O3, thus making challenging the estimation of the calculation of BVOC effect on O3 concentration at urban level. © 2013 Elsevier Ltd. All rights reserved.

Alami M.,University of British Columbia | Lazar D.,Palacky University | Lazar D.,Global Change Research Center | Green B.R.,University of British Columbia
Biochimica et Biophysica Acta - Bioenergetics | Year: 2012

Aureococcus anophagefferens is a picoplanktonic microalga that is very well adapted to growth at low nutrient and low light levels, causing devastating blooms (brown tides) in estuarine waters. To study the factors involved in long-term acclimation to different light intensities, cells were acclimated for a number of generations to growth under low light (20 μmol photons m - 2 s- 1), medium light (60 or 90 μmol photons m - 2 s- 1) and high light (200 μmol photons m - 2 s- 1), and were analyzed for their contents of xanthophyll cycle carotenoids (the D pool), fucoxanthin and its derivatives (the F pool), Chls c2 and c3, and fucoxanthin Chl a/c polypeptides (FCPs). Higher growth light intensities resulted in increased steady state levels of both diadinoxanthin and diatoxanthin. However, it also resulted in the conversion of a significant fraction of fucoxanthin to 19′-butanoyloxyfucoxanthin without a change in the total F pool. The increase in 19′-butanoyloxyfucoxanthin was paralleled by a decrease in the effective antenna size, determined from the slope of the change in F 0 as a function of increasing light intensity. Transfer of acclimated cultures to a higher light intensity showed that the conversion of fucoxanthin to its derivative was a relatively slow process (time-frame of hours). We suggest the replacement of fucoxanthin with the bulkier 19′- butanoyloxyfucoxanthin results in a decrease in the light-harvesting efficiency of the FCP antenna and is part of the long-term acclimative response to growth at higher light intensities. © 2012 Elsevier Ltd. All rights reserved.

Fares S.,Italian Agricultural Research Council | Matteucci G.,National Research Council Italy | Matteucci G.,Institute for Agriculture and Forestry Systems in the Mediterranean | Scarascia Mugnozza G.,Italian Agricultural Research Council | And 7 more authors.
Atmospheric Environment | Year: 2013

Mediterranean forests close to urban areas are exposed to polluted plumes loaded with tropospheric ozone. This is the case of Castelporziano Estate, a 6000 ha Mediterranean forest 25 km from Rome downtown on the coast of the Mediterranean Sea. In September 2011 we started an intensive field campaign aimed at investigating ozone deposition from a mixed Mediterranean forest, mainly composed by Quercus suber, Quercus ilex, Pinus pinea. Measurements at canopy level with the eddy covariance technique were supported by a vegetation survey and the measurement of all environmental parameters which allowed to calculate stomatal ozone fluxes. Leaf-level measurements were used to parameterize models to calculate stomatal conductance based on a Jarvis-type and Ball-Berry approach. We show changes in magnitude of ozone fluxes from a warm (September) to a cold period (October-December). Stomatal component explained almost the totality of ozone fluxes during the cold days, but contributed only up to 50% to total ozone deposition during warm days, suggesting that other sinks (e.g. chemistry in the gas-phase) play a major role. Modeled stomatal ozone fluxes based on a Jarvis-type approach (DO3SE) correlated with measured fluxes better than using a Ball-Berry approach. A third model based on a modified Ball-Berry equation was proposed to account for the non-linear dependency of stomatal conductance on relative humidity. This research will help the development of metrics for ozone-risk assessment and advance our understanding of mixed Mediterranean forests in biosphere-atmosphere exchange. © 2012 Elsevier Ltd.

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