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Application of bioacoustic approaches in investigation of bird species interactions and community species richness
Vokurková, Jana ; Sedláček, Ondřej (advisor) ; Remeš, Vladimír (referee) ; Szymański, Paweł (referee)
Birdsong is one of the most fascinating communication tools in the animal kingdom, whether it is used for attracting a mate or in territory defense. In my dissertation, I present evidence that we can successfully study the role of birdsong in territorial behaviour, its seasonal variability, and ultimately its role in evolutionary processes thanks to modern bioacoustic and ecoacoustic approaches. By combining the bioacoustic approach with molecular analyses, I demonstrate that in the model system of two closely related passerine species, the heterospecific song convergence in their secondary contact zone is based on cultural transmission, and not on interspecific hybridisation and/or gene introgression. My dissertation further extends into the tropical zone, which is generally characterized by less pronounced environmental seasonality compared to the temperate zone. The study of potential seasonality in singing activity and the proportion of vocalizing species in this zone therefore requires year-round monitoring, which is possible thanks to the quite recent development of automated recording units (ARU). First, we confirmed that using ARU provides very similar estimates of community composition, species richness, and abundance to traditional field methods (point counts) in the specific conditions...
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Dendrologické hodnocení lesů v oblasti sopky Kanlaon, Filipíny
Rusková, Klára
The theme of this bachelor thesis is dendrological evaluation of tropical rainforest in Mt. Kanlaon Nature park on Negros Island in Philippines. It is based on my research and cooperation with local dendrological organization. This paper is about character of a tropical rainforest, tropical climate zone description and differences between primary and secondary forest structure in Mt. Kanlaon area. The main topic is determination and description of individual woody species and their atributes. All data and information about specific tree species I could not learn myself while exploring and measuring, are aquired from local organization and other botanical or dendrological sources. Part of this study is a compact disc with photos of trees I took during my research.
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Changes of biodiversity and composition of insect communities during restoration of tropical environments
Halamová, Pavla ; Tropek, Robert (advisor) ; Čížek, Lukáš (referee)
in English Tropical rainforests are the richest habitats, but most endangered habitats on the world as well. Given the current global trend of deforestation, successful restoration of secondary forests is necessary for maintaining the rich fauna and flora of tropical rainforests. Insects are the most diverse group of animals in the tropics and they have crucial roles in an ecosystem functioning. Restoration interventions in degraded forests are nowadays more common and case studies are involving insect communities, however no review of them has been conducted. The aim of this thesis was to summarize the results of hitherto published studies dealing with the insect responses to the restoration of the tropical rainforests. With the emphasis on logged forests and lands converted for agriculture, the insect species richness, abundance, diversity, and the changes of composition were studied. If ecological conditions are suitable, insect species richness, abundance, diversity, and similarity of composition tend to increase towards primary forests for majority of insect groups. However, we observe some differences across groups of insects, based on the type and severity of disturbance, and on specific conditions on the site. Keywords: insect recovery, tropical rainforest, disturbance, species diversity,...
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Diverzita epifytů v soukromé rezervaci Green Rezerva v Nikaragui
Jashari, Anna
The bachelor thesis is partially elaborated as a review of literature focused on a natural characteristics of Nicaragua, Green Reserva private reservation and on a basic characteristics of epiphytes. The main part of the thesis was conducted as a field survey of epiphytes on a research plots in Green Reserva, Nicaragua. Collected data analysis was carried out as an inventory of epiphytes within the part of a tropical rainforest and there was given an special attention to epiphytes occurring in mangroves. There were researched both types of the epiphytes - vascular and non-vascular. The result of the work is the list of all found epiphytic species depending on the dominant forest formations (tropical rain forest, mangroves). The bachelor thesis includes the quantitative and qualitative attributes of the epiphytes occurrence, particularly depending on the epiphytes species composition, location on the types of tree or palm and location within the tree height section.
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Breeding and singing activity of rainforest birds along an elevational gradient in tropical Africa
Zenklová, Tereza ; Sedláček, Ondřej (advisor) ; Riegert, Jan (referee)
Tropical areas are usually expected to be a stable environment when compared to the temperate zone. This is true especially for the temperature and the day length which ensure relatively stable food supply. As a consequence, tropical birds, especially rainforest species, are thought to breed all year round. But even in the tropics, breeding can be synchronized with some fluctuating environmental conditions such as rainfall and differences in food supply and breeding and singing activity may occur seasonally in tropical rainforest as well. But the data for testing these assumptions are still scarce. In the first part of my thesis, I focused on the seasonality in breeding activity in various feeding guilds of birds inhabiting tropical rainforest on Mount Cameroon in three different elevations - lowland, submontane and montane forest. The second part focuses on the seasonality in singing activity at both population and species level. I also compared singing activity with the data on breeding activity. The extent of breeding activity differed between feeding guilds and I showed preferences of different guilds to different seasons for breeding. Most of the groups, especially insectivorous birds, bred in the beginning of the dry season, except of species searching for invertebrates on the ground. These...
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Environmental determinants of bird species richness and population densities in sub-Saharan Africa
Dubský, Marek ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
The research of factors influencing bird's species diversity and abundance will allow us to manage the landscape in the way to create suitable conditions for survival of species. For the purposes of this work, I divided bird assemblages into 3 groups on local level: forest birds, shrubland birds and grassland birds. The forest bird species were most influenced by height of canopy, its compactness and fragmentation of the forests. The size of the fragment, fragment matrix, isolation of the fragment and birds sensitivity to edge effect were deciding factors of number of species and individuals in each fragment. The shrubland birds were most influenced by vegetation structure in meaning of presence of shrubs, trees and grassland. They were also influenced by vegetation species composition, frequency and form of disturbances (fire, grazing), they reacted positively to transformation of landscape into agroecosystems and they reacted negatively to shrub encroachement. Grassland birds reacted to various height of grass, they reacted negatively to presence of trees and shrubs and also to disturbances caused by human. It is the least studied group of birds in Africa. As fot the elevation gradient, the lowland assemblages of birds changed to mountains assemblages at attitude of about 1250 above the sea...
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Vliv fragmentace a ztráty habitatu na primáty
Sniegon, Arthur F. ; Sedláček, Ondřej (advisor) ; Pluháček, Jan (referee)
Anthropogenic activities and human encroachment may cause profound and often irrevocable changes in an environment. This may result in challenges for most of the wildlife, including our closest extant relatives, non-human primates. Worldwide, primates may be particularly susceptible to human-induced habitat alterations owing to their large body size, social way of life, slow reproduction, large home-ranges, naturally low population densities and often strong dependence on forest cover. Three main phenomena have been described as major threats for primates: loss of the natural habitat and its conversion to human-dominated landscape, fragmentation of the remaining patches of suitable habitat, and commercial bushmeat hunting. Here I review the first two processes. If primates survive the initial disturbance, they are forced to adjust their demographic, behavioural and dietary traits. However, this may not be enough for their persistence in a long term as their genetic diversity might be compromised. Moreover, also parasitic infections may impact severely the disrupted populations. In this thesis, I reviewed the current knowledge in primates demography, population genetics, dietary changes and parasite interactions in altered habitats. Most of the studies examined the African continent and Latin America, a...
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Analýza a optimalizace inventarizačních metod v podmínkách tropického deštného lesa v peruánské Amazonii
Němec, Petr
The submitted work compares results of two forest inventories conducted on the plot of 200 ha within the forestry concession in the tropical rainforest in the Peruvian Amazon. First inventory conducted in 2007 used for field data collection the common method with tapes and mechanical compasses. The second inventory conducted in 2008 used a set of electronic devices, consisting of a field computer, laser rangefinder, electronic compass, a GPS unit and a specialized software Field-Map. In both inventories the positions of all trees with a dbh bigger or equal 400 mm were mapped and following attributes were recorded: position, species, total height, trunk height and dbh. Significant differences were discovered between both methods and the inadequacies were described. The results from the comparison study show that the method conducted using electronic devices is faster and more exact in measurement of tree attributes and in navigation on the plot. However, nor use of this method encompassed to map all the trees and that is why the distance sampling method for population density estimation was used for completion of inventory results. The population map of big trees was created and used for inventory simulations using circular and belt plots of different size and different density with the aim to find most suitable variants. Results of simulated inventories were evaluated regarding their accuracy and time expenses and the variants suitable for use in the zone were suggested.
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