Evaluation of Walnut Tree Flowering and Frost Occurrence Probability During 1961-2012

Strength and direction of the potential effect of climate change on walnuts is regionally specific (Gauthier and Jacobs, 2011) as climate change will probably affect the spatial distribution of the walnut. This paper evaluated the long-term phenological series (1961-2012) of the beginning of flowering, end of flowering and duration of flowering in walnut tree (Juglans regia) at two phenological stations located in different geographical locations of the Czech Republic but in the same climatic conditions (warm region). Phenological stages were analyzed in relation to growing degree days and to spring frosts occurrence. Onset of the beginning and end of flowering occurred earlier at Velké Pavlovice station (-2.1 and -1.3 days), and conversely occurred later at Doksany station (+1.8 and +1.0). Period of flowering shortened at Doksany station (-0.8 day) and prolonged at Velké Pavlovice station (+1.2 day). The occurrence of days with minimum air temperature < 0 oC during walnut tree flowering was more frequent at Doksany station (in total, 29 days) with absolute minimum value -5.5 oC. At Velké Pavlovice station 5 days with minimum air temperature below 0 oC were found during examined period with absolute minimum value -3.8 oC. The negative trend in number of frost days occurrence during flowering period was found at both stations. Pearson correlation coefficient between phenophase onset (and flowering period) and sums of growing degree days was stronger at Velké Pavlovice station, and the highest value was between period of flowering and temperature sums (0.782). The results confirmed our hypothesis of changes in phenophase onsets and duration of flowering including spring frosts occurrence according to west-east gradient (maritime climate-continental climate).O

Repository of drought event impacts across the danube catchment countries between 1981 and 2016 using publicly available sources

Drought directly and indirectly affects human society in a number of ways. In many regions of the world climate change will exasperate the effects of droughts, affect national economies more intensely. The main aim of this article was to catalogue and analyze the drought impacts in the 11 Central and South Eastern European states located in the Danube river basin. The identification of dry episodes was based on information from publicly available sources, namely, newspaper and journal articles that reported drought impacts. Information on drought impact occurrences was classified into one of five defined categories in which the drought impact report was most clearly manifested (i.e., agriculture, forestry, soil systems, wildfires and hydrology). In terms of the spatial distribution of drought impacts, individual recorded events were analyzed at the level of EU NUTS regions (or their equivalent in non-EU countries). The analysis highlights country-specific vulnerability to drought. Furthermore, gradual increases in drought events and the number of reported impacts were identified, which was particularly evident in the agricultural sector

Modelling the onset of phenological phases of spring barley (Hordeum vulgare L.)

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

Mikroklimatická variabilita a její vliv na fenologii vybraných druhů

Thesis on microclimatic variability and its impact on the phenology of selected species examines the influence of climatic variables on term phenological phases of agricultural crops. Thesis also study the trend and timing of the onset of phenological phases of agricultural crops during 1961-2011 and 1976-2011. Finally this work study onset of phenological phases in unmanaged ecosystems. All observations were done at three experimental sites within the region of South Moravia. Phenological data were compared in given time series for its trends and correlations. The results showed earlier onset of phenological phase heading of winter wheat. The dates of heading are also in-fluenced by climate conditions especially average and maximum air temperature in the months April and May so the preceding months of studied phenophases

Analýza fenologického vývoje vybraných druhů pro oblast Chráněné krajinné oblasti Pálava a lokality jižní Moravy

Diploma thesis named „Analysis of phenological data for given species in protected landscape area Pálava within south Moravia region“ is focused partly on processing phenological historical database which includes pheno data about various birds populations. Thesis is also focused on field observations at various exeprimental sites, especially area Pálava. Historical records came from two localities in south Moravia since 1970 till 2003 according to given species and locality. Elaboration of phenological series and trends is done for three bird species - the Great Tit (Parus major), the Blue Tit (Parus caeruleus) and the Eurasian nuthatch (Sitta europaea). For final elaboration of phenological series the computer tool AnClim was used.The results showed earlier onset of mean laying day for great tit and blue tit (by 1.1. – 5 days within the decade). Also the trend analysis showed agreement within the phenological series when comparing trends among each other or among different sites

Increasing Risk of Spring Frost Occurrence during the Cherry Tree Flowering in Times of Climate Change

Climate change affects the agroecological conditions and persistence of cherry tree flowering. Detailed evaluation of minimum air temperature and occurrence of synoptic events occurrence during spring frosts within the cherry tree flowering in the Czech Republic (Central Europe) is missing. The main objective of this study was to evaluate the above-mentioned variables during the cherry tree flowering in different parts of the country from 1924 to 2012. Our question was how the frequency of frost days occurrence changed during the cherry tree flowering. A trend analysis was conducted with the Mann-Kendall test. The onset of the beginning of flowering and end of flowering shifted to an earlier date per the whole examined period (up to −13.9 and −8.1 days) and the period of flowering extended (up to 4.1 days). The shifts were more pronounced at higher elevations. During the period of the cherry tree flowering, the trend in change of the number of frost days was negative at the lowland station (−0.3 day) and positive at the highland station (+1.2 day). At all stations, “Ap3” synoptic event (anticyclone) occurrence during cherry tree flowering on days with the highest spring frost risk (Tmin at 2 m < −1.1 °C) prevailed. The positive trend of frost-day occurrence and the negative trend of minimum air temperature in cherry tree flowering indicate that blossoms are more endangered at higher elevations

Modeling Phenological Phases of Winter Wheat Based on Temperature and the Start of the Growing Season

The phenological phases of field crops have shifted to earlier times in the Czech Republic in recent decades; additionally, they have shown correlations with temperatures from previous spring months. Using a thermal time model called PhenoClim, the correlations between temperatures and phenophases allow us to evaluate the strongest predictors (i.e., maximum temperature) and indicators of base temperatures and growing degree days for the selected phenophases of winter wheat (Triticum aestivum L.). With the help of this model, it is possible to explain 0.6–0.82% of the phase variability and to estimate the onset of phenophases for the selected time period and stations (with the RMSE values of 9.4 days for jointing, 4.3 days for heading, and 5.3 days for full ripeness). To further refine the modeled onsets of phenophases, we used satellite data, specifically the normalized difference vegetation index and the enhanced vegetation index 2 from MODIS; based on these vegetation indices, the start of the growing season (SOS) was determined. After including SOS to model PhenoClim, we modeled the onsets of phenophases, with average accuracies ranging from 6.2 to 15.2. By combining the thermal time model and remote sensing data, specifically the data concerning the determination of SOS, we can refine the modeling of the onset of full ripeness in some locations

Modeling Phenological Phases of Winter Wheat Based on Temperature and the Start of the Growing Season

The phenological phases of field crops have shifted to earlier times in the Czech Republic in recent decades; additionally, they have shown correlations with temperatures from previous spring months. Using a thermal time model called PhenoClim, the correlations between temperatures and phenophases allow us to evaluate the strongest predictors (i.e., maximum temperature) and indicators of base temperatures and growing degree days for the selected phenophases of winter wheat (Triticum aestivum L.). With the help of this model, it is possible to explain 0.6–0.82% of the phase variability and to estimate the onset of phenophases for the selected time period and stations (with the RMSE values of 9.4 days for jointing, 4.3 days for heading, and 5.3 days for full ripeness). To further refine the modeled onsets of phenophases, we used satellite data, specifically the normalized difference vegetation index and the enhanced vegetation index 2 from MODIS; based on these vegetation indices, the start of the growing season (SOS) was determined. After including SOS to model PhenoClim, we modeled the onsets of phenophases, with average accuracies ranging from 6.2 to 15.2. By combining the thermal time model and remote sensing data, specifically the data concerning the determination of SOS, we can refine the modeling of the onset of full ripeness in some locations