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Surface water temperature modelling to estimate Czech fishery productivity under climate change
Svobodová, Eva ; Trnka, Miroslav ; Kopp, R. ; Mareš, J. ; Spurný, P. ; Pechar, L. ; Beděrková, I. ; Dubrovský, M. ; Žalud, Zdeněk
Freshwater fish production is significantly correlated with water temperature, which is expected to increase under climate change and affect fish growth, productivity, and survival. This study deals with estimating the change in water temperature in productive ponds and its impact on fishery in the Czech Republic. The target fish species were common carp (Cyprinus carpio), maraena whitefish (Coregonus maraena), northern whitefish (Coregonus peled), and rainbow trout (Oncorhynchus mykiss). It was hypothesized that there would be an increasing risk of high water temperature stress for fish. Water temperature calculations based on 3-day means of air temperature were tested in several ponds in three major fish production areas. The verified model was applied to the climate change conditions determined by standardized scenarios derived from the five global circulation models MPEH5, CSMK3, IPCM4, GFCM21, and HADGEM. The results for changed climate indicated limitations for Czech fish farming in terms of prolonged periods with fish temperature stress as well as the increased number of stress periods and increased number of days within these periods. It is very likely that Czech fishery will have to change the fish species farmed in particular productive areas. In particular, higher altitudes are likely to become less suitable for the Salmonidae.
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The influence of reduced precipitation supply on spring barley yields and the ability of crop growth models to simulate drought stress
Pohanková, Eva ; Orság, Matěj ; Hlavinka, Petr
This paper evaluates the first year (2014) of results from a field experiment with spring barley (cultivar Bojos) under reduced precipitation supply. The field experiment was carried out at an experimental station in the Czech Republic and consisted of small plots in two variants and three repetitions. The first variant was uncovered, and the second was partly covered to exclude rain throughout the entire vegetation season. For plots’ partial covering, a material was used to divert rainwater away from 70% of the plots. The main aim was to determine whether there are any differences in soil water content or in grain yield size between uncovered and partly covered plots and to compare the results obtained. Data measured in this field experiment were used to compare simulations of this field experiment in the DAISY crop growth model. Subsequently, the crop growth model’s ability to simulate grain yield, which was affected by drought stress, was explored. In reality, differences in phenological development and grain yield size were not evident. Reducing precipitation supply in DAISY by about 70% led to simulations of covered plots with reduced grain yield in accordance with the initial hypothesis. Agreement between observed and simulated grain yield was evaluated using selected statistical indicators: root mean square error (RMSE) as a parameter of average magnitude of error and mean bias error (MBE) as an indicator of systematic error. RMSE of grain yield was 2.6 t ha−1. MBE revealed grain yield undervalued by 2.6 t ha−1.
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Long-term productivity of short rotation coppice under decreased soil water availability
Orság, Matěj ; Fischer, Milan ; Tripathi, Abishek ; Žalud, Zdeněk ; Trnka, Miroslav
Wood, in fact, is the unsung hero of the technological revolution that has brought us from a stone and bone culture to our present age (Perlin 1991). Given its high-energy content and versatile use, biomass in the form of wood has been used for energy purposes for millennia. The production and use of woody biomass resources has been expanding around the world. The main drivers of its use as a source of energy are diversification and mitigation of energy related greenhouse gas emissions through partial substitution for fossil fuels. An alternative to sourcing wood biomass from natural forests is short rotation woody coppice. Its productivity is largely dependent on the environment in terms of climatic conditions. Especially drought is the main constraint on woody biomass production and involves serious economic consequences. For that reason, our field experiment was designed to evaluate the impact of decreased soil water availability on productivity of a poplar based short rotation coppice plantation over multiple growing seasons during 2011–2014. Aboveground biomass productivity of treatments with and without throughfall exclusion was assessed within this study. Our results show a systematic decline in the productivity of the plots subjected to decreased soil water availability by 30% in 2011, 20% in 2012, 49% in 2013, and 51% in 2014 compared to control plot. Aboveground biomass productivity ranged from 8.8 to 9.9 t dry matter ha−1 year−1 for the control treatment and 4.5 to 8.0 t dry matter ha−1 year−1 for the treatment with throughfall exclusion.On average, the throughfall exclusion treatment exhibited 47% less productivity than control treatment had over the entire study period.
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Analysis of poplar water-use efficiency at Domanínek experimental site
Hlaváčová, M. ; Fischer, Milan ; Tripathi, Abishek ; Orság, Matěj ; Trnka, Miroslav
The main objective of this study was to test if water-use efficiency (WUE) values are higher for short-rotation poplar coppice than they are for field crops. WUE of woody biomass was determined for 16 trees within a short-rotation poplar coppiced culture (poplar clone J-105) in the within the Czech Republic during the 2013 growing season. Total WUE of woody biomass for the 16 measured trees was 4.93 g kg−1 when calculated with the data set without a vapour pressure deficit condition and 4.63 g kg−1 when calculated with the data set with a vapour pressure deficit condition. Poplar clone J-105 is a tree species with relatively high WUE, but some crops or short-rotation coppice species can reach higher or comparable WUE values.
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Leaf area index development and radiation use efficiency of a poplar short rotation coppice culture
Tripathi, Abishek ; Fischer, Milan ; Trnka, Miroslav ; Orság, Matěj ; Vanbeveren, S. ; Marek, Michal V.
Leaf area index (LAI) is the most appropriate parameter for analyzing canopy structure and crop productivity. LAI and radiation use efficiency (RUE) were estimated to evaluate the productivity of a short rotation coppice culture of a poplar clone. RUE was calculated as the ratio between total aboveground woody biomass and available photosynthetic active radiation (PAR) accumulated during one growing season. Prior to coppicing, LAI reached a maximum value of 7.3 (in 2009), whereas the maximum LAI after coppicing was 6.8 (in 2012). The maximum RUE reached prior to coppicing was 0.25 g mol−1 (in 2009), while after coppicing it was 0.20 g mol−1 (in 2012), which did not represent a significant difference (p > 0.05).
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Are there any changes in the beginning of flowering of important allergens in the Czech Republic?
Bartošová, Lenka ; Hájková, L. ; Kožnarová, V. ; Možný, M. ; Trnka, Miroslav ; Žalud, Z.
Phenological observations have a long tradition in the Czech Republic; the first phenological notes were taken in the 18th century. Within the entire phenological observation network of the Czech Hydrometeorological Institute, 45 plant species can be observed. These include perennial herbs, grass, and ground bushes growing wildly. Some observed species are among the group of so-called allergens, e.g. silver birch (Betula pendula Roth), cocksfoot (Dactylis glomerata L.), and meadow foxtail (Alopecurus pratensis L.). In this paper, we evaluated the phenological phase beginning of flowering for two of the aforementioned plants at the Mlýny, Chřibská research site (50°52’N, 14°29’E, 350 m a.s.l.). The aim was to assess which meteorological parameters influence phenological onsets as well as to analyze shifts in phenophase onset dates and temperature trends during 1959–2014. During this period, for B. pendula the average date of beginning of flowering was 28 April with a standard deviation of 10 days and for A. pratensis it was 20 May with a standard deviation of 8 days. The studied species are allergens and their timing and phenological shifting during the spring and their relationship with climate parameters may provide important information for forecasts as part of a pollen warning service.
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LINCOLN – an algorithm for filtering daily NDVI MODIS data and deriving the start of the season
Bohovič, R. ; Hlavinka, Petr ; Semerádová, Daniela ; Bálek, L. ; Tadesse, T. ; Hayes, M. ; Wardlow, B. ; Trnka, Miroslav
Monitoring drought has become an important tool for farmers and agriculture decision makers. This has increased efforts to create a monitoring system using satellite data that could provide an independent and current source of real information on vegetation condition. The aim of this study was to develop an algorithm for processing Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer. A software utility called LINCOLN was developed for this purpose. Its filtering output was further processed to yield a start of the season (SOS) metric. Different settings of the utility were tested and correlated to such phenological ground observations as the emergence of spring barley and the beginning of leaf sheath elongation in winter wheat. There was higher correlation observed in the case of winter wheat, probably due to its weaker dependence on crop sowing date. The matrix of coefficients of determination was applied to determine the optimal settings for the LINCOLN filter. The optimal absolute threshold NDVI value for SOS was set to 4,500.
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Documentary evidence as a source of data for studying droughts in the Czech lands
Řezníčková, Ladislava ; Brázdil, Rudolf ; Kotyza, O. ; Valášek, H.
Information about past droughts may be derived from the various kinds of documentary evidence. Documentary data are particularly applicable to the pre-instrumental period but may also be used for the overlapping period with instrumental records. They are extracted from written narrative sources, weather diaries, personal and official letters, newspapers, religious records, epigraphic sources, and other sources. Direct descriptions of weather facilitate identification of meteorological droughts, while descriptions of drought impacts are used to identify agricultural and hydrological droughts. Documentary evidence enabled the creation of series of precipitation indices which classify dry months on a scale of –1 (dry), –2 (very dry), and –3 (extremely dry). In this way, it is possible to study the frequency, seasonality, severity, and impacts of drought episodes in the pre-instrumental period.
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Documentary evidence in the study of past hydrometeorological extremes in South Moravia
Chromá, Kateřina ; Brázdil, Rudolf ; Valášek, H. ; Dolák, Lukáš ; Řezníčková, Ladislava
Information about hydrological and meteorological extremes (HMEs) in the instrumental period can be extended back into pre-instrumental times using documentary evidence from a variety of data sources. Financial and economic records, particularly those related to taxation data, are among the most important such sources. For the region of South Moravia, they are held by the Moravian Land Archives in the provincial capital of Brno and in certain equivalent state district archives that contain collections of estate accounts and family archives. Exploration of these sources provides information about HMEs in terms of dates and places of occurrence, courses, and impacts. Data of this kind from South Moravia were interpreted and included in a dedicated database, bringing the number of records of past HMEs to 2,010. This contribution demonstrates the high potential of this type of data.
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