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Primary Succession - study methods and pollen analysis opportunities
Suk, Pavel ; Abraham, Vojtěch (advisor) ; Prach, Jindřich (referee)
This thesis focuses on the main study methods of primary succession. It compares their advantages and disadvantages, the scales of usage and the outputs they bring. Due to the duration of a succession development (in hundreds of years), indirect approach - space-for- time substitution using chronosequences (sites that differ only in age and make up succession series) is often used instead of direct study methods. Breach of the the critical assumption that all sites follow the same trajectory may lead to false conclusions about the successional development. This thesis presents examples showing this problem, ways to prevent it and offers an alternative method - pollen analysis. Pollen analysis is on average used for larger spatial and temporal scales but partially overlaps scales of space-for-time substitution. The thesis presents biases of pollen analysis and ways how to solve/limit them and introduces abandoned, partially flooded quarries as a suitable environment for the use of this method to study succession inferred from rapidly growing limnic sediment.
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Relative pollen productivity estimates of main tree taxa of Central Europe in model area Křivoklátsko.
Fořtová, Pavlína ; Abraham, Vojtěch (advisor) ; Roleček, Jan (referee)
Pollen spectra found in sediments enable the research of quantitative changes in vegetation composition in the past. The fact is conditioned upon assumption of unchangeable linear relationship between abundance of pollen and the vegetation that is responsible for its production. Calibration of this relationship is experimentally performed on modern pollen samples and current vegetation. Relative pollen produktivity etimates (PPEs) represents basic parameters for the conversion of proportional pollen data into the vegetational ones. Their knowledge is indispensible for the quantitative vegetation restoration and for the simulating of the processes of pollen dispersion and deposition. PPEs estimation is performed by ERV model which corrects nonlinear relationship of proportional pollen and vegetation data back to the linear relationship. ERV model estimates PPEs values together with values of pollen background by maximum likelihood method. Knowledge of PPEs of main tree species is crucial for the understanding of processes which takes place on the level of landscape scale. Model area of Křivoklátsko was selected due to its high forest coverage and tree diversity. Twenty-four localities were chosen upon stratified random selection. Moss polsters containing modern pollen loading were taken and detailed...
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Long-term dynamics of Ledum palustre - testing the distribution model with paleoecological data
Radoměřský, Tomáš ; Kuneš, Petr (advisor) ; Petřík, Petr (referee)
On the territory of the Czech Switzerland National Park took place during the Holocene significant changes in vegetation cover to the form is most enrolled medium Holocene climatic optimum when broadleaf deciduous forests expanded into Central Europe. These transformations are caused by climatic changes. However, it started the process of soil acidification to this day that caused the other variations of the vegetation composition, even the extinction a variety of species especially in sandstone areas. In addition, in the last few centuries the human impact is graduating, which more or less of the original forests changes due to agricultural and economic reasons to breed-specific and the same-aged plantations which supports the already declining species diversity and relative abundance of the undergrowth species. This work focuses on a single species, evergreen undergrowth shrub Ledum palustre which is characterized by strong demands on its habitat and indicates the specific habitat type. It grows on the upper north-facing edges of rocks with plenty of light and humidity. At these locations stores organic material thanks the favourable hydrology. This makes possible to study the use of pollen and macroremains the paleoecology of the species. On the basis of recent occurrences and the relationships...
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Palynological synthesis for the Czech Republic
Abraham, Vojtěch
The aim is to gather pollen sequences and derive from them synthetic information on past species distribution and Holocene vegetation history. Lonicera nigra was selected as a model taxa. The phylogeographic hypothesis that its Alpine and Carpathian populations survived the LGM in separate refugia is supported only by the Late-Glacial record. This shrub migrated rapidly from southern to central Europe during the warm oscilations of the Late Glacial. The synthesis of vegetation history was produced by applying the REVEALS model, which can filter out following factors influencing the relationship between pollen and vegetation: pollen taphonomy, pollen productivity and pollen dispersal. It was necessary to calculate and test those parameters, so the goals were partly methodical. Pollen productivity estimates are calculated within the Relevant Source Area of Pollen, which is influenced by vegetation structure. Subsequent validation of those values in the area of the REVEALS model 10000 km2 and selection of additional values for lacking taxa created the best set of parameters for the study area. The source fossil dataset for purposes of this synthesis is the newly developed Czech Quaternary Pollen database (PALYCZ). Non-direct multivariate analysis of pollen percentages including all taxa revealed a similarity...
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Palynological synthesis for the Czech Republic
Abraham, Vojtěch ; Pokorný, Petr (advisor) ; Chytrý, Milan (referee) ; Sugita, Shinya (referee)
The aim is to gather pollen sequences and derive from them synthetic information on past species distribution and Holocene vegetation history. Lonicera nigra was selected as a model taxa. The phylogeographic hypothesis that its Alpine and Carpathian populations survived the LGM in separate refugia is supported only by the Late-Glacial record. This shrub migrated rapidly from southern to central Europe during the warm oscilations of the Late Glacial. The synthesis of vegetation history was produced by applying the REVEALS model, which can filter out following factors influencing the relationship between pollen and vegetation: pollen taphonomy, pollen productivity and pollen dispersal. It was necessary to calculate and test those parameters, so the goals were partly methodical. Pollen productivity estimates are calculated within the Relevant Source Area of Pollen, which is influenced by vegetation structure. Subsequent validation of those values in the area of the REVEALS model 10000 km2 and selection of additional values for lacking taxa created the best set of parameters for the study area. The source fossil dataset for purposes of this synthesis is the newly developed Czech Quaternary Pollen database (PALYCZ). Non-direct multivariate analysis of pollen percentages including all taxa revealed a similarity...
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Atractivity of buckwheat for bees
KOSCHANT, Jan
This diploma thesis ,,buckwheat attractivity for bees" deals mainly with native nectar plants for the processing of bees to honey. Work is folded in two parts. The theoretical part deals with the migration of colonies, both for nectar crops and plants with bee pollination needs. In ractical part of this thesis microscopic pollen analysis were performed and contents of pollen grains in honey from colonies, which were relocated to buckwheat growth was evaluated. Comparison of this honey with honey from the hives with similaar location, but without access to buckwheat growth was done.
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Evaluation of the attractiveness of individual plants and types of pollen for honey bees in depending on their action radius range in Mladá Boleslav area (Central Bohemia).
Kroupa, David ; Farkač, Jan (advisor) ; Vítězlav, Vítězlav (referee)
The aim of my bachelor thesis was to create a summary of pollen pasture of the European honey bee in the Mladá Boleslav area.
In theoretical part, I have put together basic information related to the European honey bee and pollen (bee colony, body structure, bee evolution, bee communication, pests and diseases, bee and plant relationship, harvesting and consumption of pollen, pollen load and bee products).
In the practical part, I have determined the pollen load's origin by analyzing pollen. This method was carried out with an illuminated binocular microscope. The plants are sorted into families. This data was then used in statistics, graphs and charts.
Altogether, It was collected 4 721 pollen loads between the years 2015 and 2016. I gathered 2 553 samples in 2015 and 2 168 samples in the following year. The biggest pollen pasture was offered by the Brassicaceae family in 2015 and by family Lamiaceae in 2016.
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Krajinna raného středověku a její změny s nástupem kolonizace
Kozáková, Radka ; Pokorný, Petr (advisor) ; Latalowa, Malgorzata (referee) ; Svitavská - Svobodová, Helena (referee)
Landscape transformation that occurred during the Middle Ages in western and central Europe is reflected in all pollen diagrams. An event that was so striking and widespread was used by Firbas to distinguish a biostratigraphical period called the Younger Subatlantic (zone X; Firbas 1949). High Medieval landscape transformation is connected with rapid colonization in our area that resulted in extensive deforestation and intensified agriculture. During the first half of the 13th century, the settlement network was already stabilized and was very similar to the current state and was reaching also mountain areas (Klápště 1994). New organization and changes in land ownership, as well as a need for more effective agriculture, resulted in the connecting of small fields into larger ones and in an increase of cultivated area (Klápště 2006). The use of the land was different, and for the first time complete (Bakels 2009). During a few centuries anthropogenic factors that were enormously enhanced throughout the 13th century, formed a cultural landscape that was much more similar to the landscape of today than to the landscape of, for instance, the 9th century. This doctoral thesis is focused on the Early Medieval landscape in the Czech lands and its transformation that culminated during the 13th and 14th...
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Natural forest disturbances palaeoecology
Moravcová, Alice ; Pokorný, Petr (advisor) ; Novák, Jan (referee)
This Bc. thesis deals with the disturbances, which form an integral part of many ecosystems. The main foci are natural disturbances (in contrast to anthropogenic ones) of temperate and boreal forests. I deal with the causes of major disturbancy factors (fires, storms, disease and insect pathogens) and their impact on the ecosystem. I focused in detail on fires, because they represent an essential factor in the development of many ecosystems. Moreover, they can be studied in the past by using several tools of palaeoecological analysis: dendroecology, anthracology and pollen analysis combined with micro-charcoal particles quantification. The last part of the thesis discusses the role of disturbances in the secular succession of Holocene vegetation in Central Europe. It contains a chapter that describes a research strategy focused to the study of natural disturbances through paleoecological methods in a specific location (Rynholec, Central Bohemia). Key words disturbances, vegetation dynamics, fire dynamics, secular succession, palaeoecological methods
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Relative pollen productivity estimates of main tree taxa of Central Europe - assumptions for data collection.
Šourková, Pavlína ; Abraham, Vojtěch (advisor) ; Kuneš, Petr (referee)
Quantitative reconstruction of vegetation from fossil pollen data makes is possible to learn about historical development of the flora of a particular area and, thus, to a certain degree about the climate changes as well. Parameters (the so-called pollen productivities) needed in order to convert the pollen data into the vegetation data can be acquired by calibration from modern samples. The constancy of these parameters in time is assumed on the basis of the principle of uniformitarianism. Due to climatic conditions, however, pollen productivities are not constant in space and must be estimated for each region separately. The pollen and vegetation percentage data can be used to carry out relative pollen productivity estimates (PPE). The relative pollen productivities are related to a reference taxon, which has a value of 1 and vegetation abundance expressed by content units. Relative pollen productivities are estimated by means of the so-called ERV models. Before entering the ERV models, the vegetation data must be weighed by the distance in order to take into account the fact that the more remote plants contribute to the sample with a smaller quantity of pollen than the nearer ones. It is the Prentice-Sugita model of pollen dispersion ant disposition that is currently the most appropriate...
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