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Pollinator movement and orientation at small spatial scales
Matoušková, Eva ; Janovský, Zdeněk (advisor) ; Tropek, Robert (referee)
Pollination is interesting andcomplex interaction between insects and plants which is essential for a wide spectrum of plants and animals. Hoverflies (Diptera: Syrphidae) and bees (Hymenoptera: Anthophila) are one of the most common pollinators in the Central Europe and are mostly involved in pollination of local plants. To maintain pollination, it is necessary the movement of pollinator from one flower of a specific species to another flower of the same species. This movement is affected by a number of factors based on both the environmental and pollinator traits. The aim of this work is to explore the nature of traits affecting pollinator flight between plants on small spatial scales, to classify the knowledge about the influence of pollinator and ambient effects to compare the differences between hoverflies and bees and suggest further possible fields of research. Keywords: pollination, hoverflies, bees, Syrphidae, Anthophila, movement
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Floral biology of temperate and tropical alpine plants
Nekola, Matyáš ; Sklenář, Petr (advisor) ; Janovský, Zdeněk (referee)
From all alpine ecosystems are tropic ones the most distinct, mainly due to aseasonality of their climate. In temperate alpine ecosystems seasonality causes annual changes in temperature and creation of snow cover. On the other hand, in tropical alpine ecosystems annual mean temperatures stay approximately same, but thanks to the high radiation heat loss at night temperatures vary significantly throughout the day diurnal. These environments also differ in change of day length throughout the year, altitude and atmospheric pressure. Plants created diverse adaptations in response to these different conditions. In temperate alpine ecosystems most of plants preform their floral primordia at least one year in advance. Flowering is initiated by photoperiod, temperature and combination of two previous factors, or immediately after the end of dormancy. Early flowering species are limited by the transfer of pollen and are allogamous. Late flowering species are autogamous. Main pollinators are from order Diptera. In tropical alpine ecosystems initiation of flowering correlates with decrease of minimal night temperatures and change in water availability. Asynchronously flowering species tend to be allogamous and autogamy prevails at synchronously flowering species. The most important pollinators are from genus...
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Pollination in forest ecosystems
Veljačiková, Hana ; Janovský, Zdeněk (advisor) ; Hadrava, Jiří (referee)
Interactions between plants and their pollinators in temperate forest are different from open habitats. In forest, pollinators are less abundant and this results in frequent pollen limitation of forest understory herbs. Pollinators also need to be adapted for flying in complex stands and for living in unfavorable microclimatic conditions. Floral resources predominantly limit pollinator abundance because of their uneven distribution in space and time. In the present bachelor thesis, I summarize knowledge on pollinator conservation and phenology as well as food resources, microclimate, which together with sufficient nesting options seem to contribute the most to pollinator abundance. Type of forest management is also an important factor, which affects density and diversity of pollinators. Generally, thinning out of trees and removal of understory shrubs have positive effect on flower abundance and benefit pollinators. Factors that influence reproduction success of flowers and pollen transfer distances are further discussed.
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The role of biotic interactions in population biology of meadow plants
Janovský, Zdeněk
In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....
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The role of insect herbivory in plant population dynamics - a case study of the Lycaenidae family
Barusová, Anna ; Janovský, Zdeněk (advisor) ; Sedláček, Ondřej (referee)
Herbivory is one of the key interactions of plants, which can result in important consequences for their population dynamics and which can also exert selection pressure on evolution of their traits. This bachelor thesis is concerned with insect herbivore influence on plants at the levels of individuals and population dynamics. It also focuses on interactions of occurrence of herbivory with environmental conditions. This is demonstrated on the family Lycaenidae (Lepidoptera) which is highly specialized in terms of host plants with several cases of coevolution having been described. Some Lycaenid species also evolved associations with ants probably, which help to increase their range of host plants. The relationship of feeding strategies and myrmecophily is illustrated on Czech species of Lycaenidae. The last part focuses on the Great Burnet (Sanguisorba officinalis) and its European-wide declining monophagous herbivore Dusky Large Blue (Phengaris nausithous), their ecology and conservation. Ecology of this study system will be the main topic of the intended master thesis.
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Pollination efficiency as a function of plant spatial aggregation and pollinator functional traits
Štenc, Jakub ; Janovský, Zdeněk (advisor) ; Tropek, Robert (referee)
Pollen transfer between zoogamous plants is strongly influenced by spatial structure of plant population and functional traits of its vectors - pollinators. Spatial structure of plants can be described by attributes that may affect pollen transfer, such as population size, density, aggregation and composition of surrounding plants. Both the main pollintor groups and individual pollinators differ in pollen transfer distance, pollen carry-over capacity, food specialisation, preferences and sensoric abilities. Due to these differences, they vary in impact on pollen transfer in a different spatial structure of plant population. Understanding the impact of individual attributes of both of these components and their influence on pollination can help us to get a better idea of how sexual reproduction works at the plant population level. Key words pollination, plant-pollinator interactions, spatial structure of population, pollen transfer, pollinators, sexual reproduction of plants
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The role of biotic interactions in population biology of meadow plants
Janovský, Zdeněk ; Herben, Tomáš (advisor) ; Lepš, Jan (referee) ; Ehrlen, Johan (referee)
In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....
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Interactions of herbivore funtion gourps and Succisa pratensis
Šulcová, Hana ; Janovský, Zdeněk (advisor) ; Roubíčková, Alena (referee)
Herbivory is one of most important factors which form meadow ecosystems. These ecological communities have one of the biggest variety of species in Central Europe and their research is important in terms of management of protected species as well. Localities which has a similar importance, is also a meadow ecosystem with occurrence of Succisa pratensis, the only host plant for rare butterfly Euphydryas aurinia. Research of Succisa and its other herbivores can improve a protection of this particular butterfly. Effects of herbivores of Succisa were examined by several experiments. The first one was a field cage experiment. Its aim was to detect what kinds of herbivores (rodents and invertebrates) are involved in herbivory of leaf rosettes of Succisa and what is their impact on the fitness of these plants. The intensity of herbivory of Succisa was measured for over two vegetation seasons on the month bases. In this experiment were also examined effects of surrounding vegetation on the studied plants of Succisa. The second experiment was performed in a garden. Its aim was to clarify the role of herbivores of leaf rosettes, stalks and their interactions on the fitness of Succisa. The third experiment was concerned to true bugs, which are pre-dispersal predators of seeds of Succisa. Their effects on...
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Succisa pratensis and impacts of herbivores on individual fitness
Janovský, Zdeněk ; Pergl, Jan (referee) ; Münzbergová, Zuzana (advisor)
Zdeněk Janovský Succisa pratensis and impact of herbivores on individual fitness In this master thesis I tried to examine the impact of three herbivore groups on both short- term and long-term fitness of Succisa pratensis individuals. Concretely I studied these three herbivore groups: (i) folivores; (ii) stalk grazers; and (iii) seed predators. The impact of folivores and stalk grazers was studied in a four-year study on repeatedly censused individually marked S. pratensis plants on six sites. The impact of seed predators was studied in a separate experiment. Stalk grazers and seed predators have a direct negative influence on short-term plant fitness. However, the impacts of stalk grazing were offset by affected plants by means of increased long-term flowering probability. On the other hand folivores have a long-term negative effect on plant reproductive effort despite their short-term positive influence on survival and clonal reproduction. Probable explanation of this observed phenomenon could be due to the influence of folivores on reproductive effort of the plants already in the year of their occurrence. The impact of seed predators is very variable, although higher plants suffered from higher proportion of destroyed seeds. A conceptual model of possible impacts of these three herbivore groups on...
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