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Seasonal and long-term dynamic of plankton communities of small water-bodies
Pejsar, Patrik ; Černý, Martin (advisor) ; Juračka, Petr Jan (referee)
Zooplankton pool-inhabiting organisms form metacommunities and metapopulations. Locations are connected through dispersion which is an essential part of colonization-extinction dynamic. Locations vary with the environmental conditions, the specifics of the community and the biotic interactions taking place there. Differences in these parameters may occur between spatially separated pools or in one pool throughout time. These changes are caused by seasonal dynamics, disturbances, long-term development of environmental conditions or biotic factors such as predation, competition and parasite influence. On a long-term scale the locations are classified into rather stable and ephemeral. In pool environment the ephemeral locations may unexpectedly be the driving force of metacommunity and metapopulation processes according to the "inverse mainland-island" theory. Global climate change has an essential influence on zooplankton dynamic in smaller water-bodies. Hydrology of pools and through it also life dynamics of plankton organisms is directly influenced by temperature changes and precipitation. Regional metacommunity and metapopulation dynamics are changing in dependency on regional course of climate change and the specifics of these water-bodies and the communities living there.
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Development of resistant life stages and mechanisms of passive dispersal of freshwater copepods
Šliková, Adéla ; Juračka, Petr Jan (advisor) ; Fott, Jan (referee)
Copepods are an important part of metacommunities in freshwater and marine ecosystems. Freshwater copepods occur at all continents and are found in almost every water habitat. These small invertebrates cannot actively disperse among habitats and therefore have to rely on vectors of passive dispersal. Copepods can produce diapause life forms and are therefore able to survive unfavorable conditions during the transport. Throughout the ontogenetic development from an egg to adult stage, they have to pass naupliar and copepodit life stages. Various evolutionary lineages of copepods developed diapause phase at different life stage. Hence it is possible to observe both diapausing eggs as well as diapausing adults. Discussed vectors of passive dispersal are wind, floods, animal fur, animal gut, but also human recreational and industrial activity. This work summarizes basic knowledge about the mechanisms of development of copepods diapausing life stages and about their passive dispersal. Key words: passive dispersal, freshwater copepods, diapause
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Freshwater fishless pools: from the metacommunties to the systematics
Juračka, Petr Jan ; Petrusek, Adam (advisor) ; Kotov, Alexey (referee) ; Zhai, Marie (referee)
Freshwater fishless pools: from the metacommunities to the systematics Petr Jan Juračka, Ph.D. Thesis, 2016-04-08 ABSTRACT Despite their small size, freshwater fishless pools often contain complex communities and substantially increase regional invertebrate and macrophyte biodiversity. The main core of this thesis originates from such habitats, which were newly created for the conservation purposes in the Protected Landscape Area Kokořínsko, Czech Republic. This landscape consists of deep valleys separated by steep sandstone ridges and is characteristic for very sparse stream network and low number of large water habitats, which consequents in generally low abundance of waterfowl. We studied microcrustacean metacommunities of 42 selected pools scattered over the area of approximately 220 km2 . Using variation partitioning of the species composition, analyses of the species richness and colonization experiment in the study area, we identified that spatial distribution of the habitats and number of neighbouring aquatic habitats play a major role in assembly of local communities. This led us to the conclusion that the landscape heterogeneity served as a partial barrier to dispersal of microcrustaceans. Subsequently, we compared this pattern of the microcrustacean metacommunity with other invertebrates of...
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Freshwater fishless pools: from the metacommunties to the systematics
Juračka, Petr Jan
Freshwater fishless pools: from the metacommunities to the systematics Petr Jan Juračka, Ph.D. Thesis, 2016-04-08 ABSTRACT Despite their small size, freshwater fishless pools often contain complex communities and substantially increase regional invertebrate and macrophyte biodiversity. The main core of this thesis originates from such habitats, which were newly created for the conservation purposes in the Protected Landscape Area Kokořínsko, Czech Republic. This landscape consists of deep valleys separated by steep sandstone ridges and is characteristic for very sparse stream network and low number of large water habitats, which consequents in generally low abundance of waterfowl. We studied microcrustacean metacommunities of 42 selected pools scattered over the area of approximately 220 km2 . Using variation partitioning of the species composition, analyses of the species richness and colonization experiment in the study area, we identified that spatial distribution of the habitats and number of neighbouring aquatic habitats play a major role in assembly of local communities. This led us to the conclusion that the landscape heterogeneity served as a partial barrier to dispersal of microcrustaceans. Subsequently, we compared this pattern of the microcrustacean metacommunity with other invertebrates of...
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Metacommunities of the copepods, molluscs and ostracods in Kokořínsko pools on the longterm gradient
Tichá, Adéla ; Juračka, Petr Jan (advisor) ; Šorfová, Vanda (referee)
Re-creation and building new small freshwater habitats belong among the important management activities within the Protected Landscape Area Kokořínsko - Máchův kraj (Czech Republic) for almost two decades. These pools keep the water within the landscape and serve as the habitats for vulnerable species of amphibians and invertebrates, which I have studied within this thesis. Most studies focusing on studying metacommunities of small water bodies have been based on the data from one or two seasons, and thus completely neglect the development of composition of these metacommunities over longer periods of time. This thesis builds on previous research on the species composition of small ponds in the Kokořínsko Protected Landscape Area, which had been done in 2005 and 2006. In 2009 and 2017, sampling in the same ponds continued. I investigated the influence of spatial and environmental variables of individual ponds on the species composition of ostracods, copepods and molluscs in specific years and how has the representation of individual species changed among those years. With one exception, I have not observed any new incoming species of copepods and ostracods since 2006; the number of species had in fact decreased. In the case of molluscs, there was a significant exchange of species between individual...
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Factors affecting the metacommunity structure of major freshwater invertebrate groups
Nagy, Alexander ; Juračka, Petr Jan (advisor) ; Černý, Martin (referee)
Freshwater organism communities are dependent on the ability of dispersion among habitats through inhospitable terrestrial environment. Therefore, these organisms have developed a variety of dispersal mechanisms. Some species are able to overcome barriers via active dispersion, but most freshwater invertebrates are passive dispersers, depending on abiotic or biotic vectors. Abiotic vectors are e.g., wind or floods, while biotic vectors are other animals such as birds. By linking several locations with dispersion, and thus with a gene flow, a meta- community is created. This is influenced by many factors, including habitat abiotic conditions, especially altitude, and biotic interactions, such as competition and predation. Freshwater invertebrate communities are very complex and influenced by many factors with varying degrees of influence.
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Freshwater fishless pools: from the metacommunties to the systematics
Juračka, Petr Jan
Freshwater fishless pools: from the metacommunities to the systematics Petr Jan Juračka, Ph.D. Thesis, 2016-04-08 ABSTRACT Despite their small size, freshwater fishless pools often contain complex communities and substantially increase regional invertebrate and macrophyte biodiversity. The main core of this thesis originates from such habitats, which were newly created for the conservation purposes in the Protected Landscape Area Kokořínsko, Czech Republic. This landscape consists of deep valleys separated by steep sandstone ridges and is characteristic for very sparse stream network and low number of large water habitats, which consequents in generally low abundance of waterfowl. We studied microcrustacean metacommunities of 42 selected pools scattered over the area of approximately 220 km2 . Using variation partitioning of the species composition, analyses of the species richness and colonization experiment in the study area, we identified that spatial distribution of the habitats and number of neighbouring aquatic habitats play a major role in assembly of local communities. This led us to the conclusion that the landscape heterogeneity served as a partial barrier to dispersal of microcrustaceans. Subsequently, we compared this pattern of the microcrustacean metacommunity with other invertebrates of...
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Development of resistant life stages and mechanisms of passive dispersal of freshwater copepods
Šliková, Adéla ; Juračka, Petr Jan (advisor) ; Fott, Jan (referee)
Copepods are an important part of metacommunities in freshwater and marine ecosystems. Freshwater copepods occur at all continents and are found in almost every water habitat. These small invertebrates cannot actively disperse among habitats and therefore have to rely on vectors of passive dispersal. Copepods can produce diapause life forms and are therefore able to survive unfavorable conditions during the transport. Throughout the ontogenetic development from an egg to adult stage, they have to pass naupliar and copepodit life stages. Various evolutionary lineages of copepods developed diapause phase at different life stage. Hence it is possible to observe both diapausing eggs as well as diapausing adults. Discussed vectors of passive dispersal are wind, floods, animal fur, animal gut, but also human recreational and industrial activity. This work summarizes basic knowledge about the mechanisms of development of copepods diapausing life stages and about their passive dispersal. Key words: passive dispersal, freshwater copepods, diapause
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Progress in photography and video and its impact for origin of timelapse
Ciml, Michal ; Truhlář, Filip (advisor) ; Juračka, Petr Jan (referee)
The bachelor thesis deals with history of photography and video and its importance for the development of a specific photographic techniques - time lapse video. The thesis discusses in more detail the composition and its rules in timelapse creation. Further, a procedure of making according to the author of this thesis and its experience are presented. The author draws on, among other things, information from Gunther Wegner, the world-known timelapse author, whom he met several times personally. The reader of this work should gain awareness of the history, composition and timelapse creation. The thesis should also be a source of information by which also a layman can create his first timelapse and should help him to avoid basic mistakes of a beginner.
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Seasonal and long-term dynamic of plankton communities of small water-bodies
Pejsar, Patrik ; Černý, Martin (advisor) ; Juračka, Petr Jan (referee)
Zooplankton pool-inhabiting organisms form metacommunities and metapopulations. Locations are connected through dispersion which is an essential part of colonization-extinction dynamic. Locations vary with the environmental conditions, the specifics of the community and the biotic interactions taking place there. Differences in these parameters may occur between spatially separated pools or in one pool throughout time. These changes are caused by seasonal dynamics, disturbances, long-term development of environmental conditions or biotic factors such as predation, competition and parasite influence. On a long-term scale the locations are classified into rather stable and ephemeral. In pool environment the ephemeral locations may unexpectedly be the driving force of metacommunity and metapopulation processes according to the "inverse mainland-island" theory. Global climate change has an essential influence on zooplankton dynamic in smaller water-bodies. Hydrology of pools and through it also life dynamics of plankton organisms is directly influenced by temperature changes and precipitation. Regional metacommunity and metapopulation dynamics are changing in dependency on regional course of climate change and the specifics of these water-bodies and the communities living there.
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