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Aesthetic value of biodiversity
Schmitzová, Daniela ; Hořák, David (advisor) ; Braun Kohlová, Markéta (referee)
The aesthetic experience of nature is a crucial part of human life. Because aesthetic experiences motivate people to engage in nature conservation, it makes sense to consider how biodiversity influences aesthetics and whether this influence can be used to promote conservation. First, this review touches on the measurement of nature's value to people and biodiversity, then discusses studies dealing with the connection of biodiversity and aesthetics. Nature offers a range of health benefits to people (e.g. stress relief, better recovery after surgery) that increase with biodiversity, but these benefits don't seem to increase the aesthetic value. At the landscape scale, heterogeneity of the environment is of particular importance, as is the presence of water bodies. For plant communities, biodiversity has a positive correlation with aesthetic value, and perceived biodiversity has a stronger effect in that regard. Preference is also influenced by the arrangement of planting. Aesthetically motivated nature conservation can potentially bolster biodiversity, as proven by the Lower Wisconsin State Riverway area, and should be considered a valuable conservation approach. Key words: biodiversity, aesthetics, species richness, functional diversity, value of the community/ecosystem, nature conservation
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Biodiversity-productivity relationship in desmid communities
Škvorová, Marie ; Škaloud, Pavel (advisor) ; Nedbalová, Linda (referee)
This thesis deals with biodiversity-productivity relationship in desmid communities. Biodiversity is found to be changing globally. The biodiversity-productivity relationship is therefore an important research topic. Three aspects of biodiversity are thought to play an important role: species richness, functional diversity and phylogenetic diversity. It is known that in general, productivity is positively correlated with diversity. Interactions between different metrics of biodiversity are known less. Existing studies have shown that these interactions might be present. In general, biodiversity-productivity studies were mostly focused on plants. Less is known about other organisms, including algae. In this work I explore the relationship between overyielding and functional or phylogenetic diversity on a species richness gradient of desmid communities. I conducted an artificial biodiversity- ecosystem functioning experiment using combinations of two to 12 desmid species. Communities differed in the diversity aspects. I had measured the biomass growth. For the analysis, I have used the overyielding index, which is based on a comparison of a polyculture production with the production expected based on monoculture yields. The relationship of overyielding on functional diversity depended on species...
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Universality in biodiversity trends
Bohdalková, Eliška ; Storch, David (advisor) ; Keil, Petr (referee)
Biodiversity trends (such as the relationship between species richness and temperature or productivity) are always defined for a particular taxon at a specific area (the entire range of the taxon or often just a region arbitrarily chosen by researchers). The form of these trends varies between taxa and regions. The weak relationship between richness and temperature or productivity is sometimes interpreted as a counterevidence for the hypothesis explaining diversity patterns by these variables. However, the delimitation of taxa or region may play a crucial role for the form of the trends. The aim of this thesis is to determine whether some taxon properties (its size) or region properties (its area, range of explanatory variables, the temperature-productivity relationship or average temperature) affect the strength and slope of the richness-temperature and richness-productivity relationships. 46 data sets of species richness for a wide range of plants, invertebrates and ectothermic vertebrates within different regions of the world were used for the analysis. While the taxon size is likely to affect the strength and slope of the relationship when comparing individual (nested) subclades within larger clade, the comparison of different taxa in different regions of the world shows only the effect of the region...
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Drivers of avian diversity on an altitudinal gradient of Mount Cameroon
Djomo Nana, Eric ; Hořák, David (advisor) ; Šálek, Miroslav (referee) ; Waltert, Matthias (referee)
Altitudinal gradients constitute a powerful test system for understanding distribution of species around the globe. Tropical mountains are quite rich in species even after controlling for environmental productivity, and are ideally suited for studying patterns of species distributions because they have had sufficient time for species to produce a response to environmental changes that affect their life histories. In this thesis, I investigate basic ecological mechanisms potentially behind avian distribution patterns along an altitudinal gradient in West-Central Africa. I used data collected with four methodological approaches (point counts, mist netting, random walks and artificial nest experiments) along an altitudinal gradient on Mt. Cameroon from October 2011 to September 2013. This work is focused on two interrelated themes: selection pressures on life histories (Chapters 1, 2, 3 & 4), and avian assemblage structures (Chapters 5 & 6). In the General Introduction, I present an overview of the study area with conservation implications of the study and my study objectives. In Chapters 1, 2 & 3, I investigate how selection pressures, i.e., nest predation and parasitism by haematozoa, affect bird assemblages. I used artificial nest experiments to assess nest predation rates in Chapters 1 & 2, and my...
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Mountains as islands
Kačabová, Petra ; Storch, David (advisor) ; Ferenc, Michal (referee)
In this paper I deal with island biogeography and its applicability to isolated mountaintops, as an ecological equivalent of true islands. I discuss both true and mountain islands regarding their origin and the influence of long-term climate evolution on Earth. I underline some features of mountain islands, resulting from their topography and the dissimilarities of both types of island barriers. I find that mountain and true island communities might or might not have a number of species in a state of equilibrium, caused by balance between species immigration on island and their extinction. If the number of species on island is not in equilibrium, species extinction is not balanced by species immigration. I consider patterns of island communities, mainly nestedness, which has been frequently studied on mountain, as well as true islands. I discuss distribution patterns concerning invertebrates. And finally, I concentrate on recent methods of moutain island research and discuss mountain island isolation issues in terms of global warming.
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Methods used to study the effects of grazing on vegetation
Hyklová, Lucie ; Münzbergová, Zuzana (advisor) ; Šlechtová, Anna (referee)
Calcareous grasslands are one of the most diverse habitats of Northern and Central Europe. Most of the calcareous grasslands were created by human agricultural activities and therefore they need some kind of management for their long-lasting maintenance. These habitats have been vanishing during last few decades and that's why there were many experiments provided all around the world to examine possible ways of their restoration and preservation. Grazing of livestock has been a traditional management in many places and is often being investigated nowadays. The aim of this work is to search and compare methods that are used to experimentally study the effects of grazing on vegetation. These experiments use different methods although they usually have the same goal - high species richness. Most of these studies are from Great Britain, Germany and states of Northern Europe. Average length of the experiment is seven years. Key words: grassland, grazing, management, restoration, methods, species richness
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Factors affecting dragonfly species composition in newly created pools and assessment of invertebrate predation on pools zooplankton
Dobiáš, Jakub ; Černý, Martin (advisor) ; Harabiš, Filip (referee)
To identify and quantify the influence of physico-chemical, biotic and geographic factors on the population of dragonflies (Odonata) is an essential tool for research of their ecology. The aim of this study was to 1) assess how these factors influence species richness, diversity and spatial distribution of dragonflies in 42 newly constructed or renewed pools located in the Kokořínsko Protected Landscape Area, which is characterized by two valleys of Liběchovka and Pšovka creeks, low human impact, and a great diversity of small water bodies and 2) use laboratory experiments in order to estimate the relationship between large predatory invertebrates of these pools (Aeshna cyanea, Coenagrion puella, Chaoborus crystallinus and Notonecta glauca) and their common prey (Daphnia curvirostris) in an artificial environment with or without aquatic macrophytes. The pools were monitored and sampled between years 2005 and 2006. In total, 23 dragonflies species were found inhabiting these lentic habitats, comprising 11 species belonging to the suborder Zygoptera and 12 species belonging to the suborder Anisoptera, including a rare species Sympetrum depressiusculum (larvae). Most variability in the dragonfly species richness was explained by the size of the water surface area, followed by the location of the pools (inside...
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On the Nothernmost and Southernmost Limits of European Land Snail Spatial Ranges
Křepelová, Lucie ; Juřičková, Lucie (advisor) ; Horsák, Michal (referee)
The aim of this work was to evaluate the limits of ranges of European land snail species along the north-south gradient. To work out the document it was necessary to prepare the set of digitalized maps, that enabled to create the database of ranges of the individual land snails species. Based on obtained data I tried to identify places where the northern and southern borders of species ranges are the most frequent. The landsnails' ranges are affected not only by particular life requirements of the individual species (potential limits), but also by other conditions, especially climatic, geographical and historical (truncated limits). In this work I focused on their differentiation. Above mentioned process also enabled me to track the north- south changes in species richness of the landsnails taking into consideration the truncated and potential limits. The most important natural barriers constraining that numerous of species cannot naturally widespread from the south to the north are the Scandinavian Mountains, the Alpes and the Carpathians and suprisingly also southern borders of german and polish lowlands. On the other hand, spreading of the species form the north to the south is limited only by the Alpes. I also tried to distinguish the group of species whose ranges are not influenced by these...
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Phytoplankton of the Tatra lakes: factors influencing taxonomic composition and biomass
Červenková, Lenka ; Nedbalová, Linda (advisor) ; Štefková, Elena (referee)
The aim of this diploma thesis was to describe species composition and biomass of phytoplankton in the Tatra Mountains lakes (Slovakia, Poland) and environmental factors influencing them. The surface layer of 89 lakes was sampled in September 2004. Flagellates from Chrysophyta, Dinophyta and Cryptophyta most frequently dominated the phytoplankton biomass. Lake in the same valley usually differed in their dominant taxonomic group as a result of different lake morphometry, catchment type and detailed geological structure. Based on the level of phytoplankton biovolume, the majority of lakes were ultraoligotrophic and oligotrophic, however, mesotrophic and even eutrophic conditions were recorded in some forest and meadow lakes. An allometric relationship between phytoplankton biomass and chlorophyll a was revealed. Specific chlorophyll content did not differ among taxonomic groups. Altogether 233 species were determined, the most diverse group were Chlorophyta. Species richness of lake was 3-46 and it was negatively correlated with altitude and positively correlated with lake area. The majority of species were rare both in term of biomass and number of lakes occupied by a particular species. Average local species biomass was positively correlated with regional distribution. The similarity of species...
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