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Dynamics of pollination networks in time and space
Matějková, Zuzana ; Hadrava, Jiří (advisor) ; Tropek, Robert (referee)
This bachelor's thesis focuses on changes in pollination networks on different spatio-temporal scales. It covers in detail the essence and magnitude of these changes in communities of pollinators and plants. The thesis outlines the consequences of these changes for these communities and the way it affects the methodological aspects of studying plant-pollinator networks. I present the existing dynamics of Pollination networks on broad geografical scales as well as changes in local communities. I also describe the temporal changes of communities of plants and pollinators, consisting of diurnal and seasonal dynamics, not exluding the changes on even broader temporal scales. It has been shown that plant-pollinator networks are highly dynamic in space and time. These dynamics consist of species and interaction turnover, as well as of changes in the overall diversity of communities of plants and pollinators. Biodiversity dependent characteristics of pollination networks are affected by the described spatio-temporal dynamics, while characteristics that are biodiversity independent stay relativly stable on broader temporal scales.
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Diversity of bird species along elevational gradient on Cameroon mountains
Dubský, Marek ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
The aim of this thesis is to describe the changes of bird species diversity along elevation gradient on six mounts in Cameroon and nearby Bioko island. The results of the analyses confirm most of the defined hypotheses, especially they show that species diversity declines with altitude and rises with area. The absolutely highest diversity was detected on mount Kupé and mount Cameroon, but above 2100 m above sea level mounts Oku and Manenguba are the most diverse. Other analysis showed that the biggest changes in beta diversity of bird assemblages along altitudinal gradients are on the lowest elevational belts which are on the edges of a degraded habitats and continuous undisturbed forests. Other important changes in bird assemblages happen around altitude 1200 m, where the assemblages of lowland rainforest change to assemblages of mountain forest. Analyses of affinity of bird species to forest habitat showed that the most affined assemblages to the forest are those found on mounts Kupé and Rata. On the other hand bird assemblages on mounts Manenguba and Oku are the one of least affined to the forest biotope. Analysis of habitat generalism and specialism did not show the expected outcome and for clearer results the design of analysis needs to be improved. The results of this thesis contribute to a...
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Diversity and abundances of birds along altitudinal gradients of Cameroon Mountains
Dubský, Marek ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
The aim of this thesis is to describe the changes of bird species diversity along elevation gradient on six mounts in Cameroon and nearby Bioko island. The results of the analyses confirm most of the defined hypotheses, especially they show that species diversity declines with altitude and rises with area. Cluster analysis shows the similarity of individual mountains in particular altitude zones. Despite the original hypothesis, mount Cameroon is found to be most similar to mount Kupé, although high mountain assemblages of mount Cameroon and Bioko island are very alike as well. The absolutely highest diversity was detected on mount Cameroon and mount Kupé, but above 2100 m above sea level mounts Oku and Manenguba are the most diverse. The results of this thesis contribute to a clearer notion about factors influencing species diversity; however, more thorough data (particularly from mount Nlonako) and data extension for e.g. bird abundance would enrich the study and it would enable us to perform more detailed diversity analysis, especially an analysis of competition relationship among species. Key words Species diversity, Cameroon, bird assemblages, elevational gradient
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Bird assemblage structure on elevational gradient of Mt. Cameroon
Mudrová, Karolína ; Sedláček, Ondřej (advisor) ; Sam, Kateřina (referee)
Altitudinal gradients represent useful tool for investigating diversity patterns and processes affecting species richness and turnover along steep gradient of conditions at relatively small scale. The aim of my study was to compile a complete checklist of birds for elevational gradient of Mt. Cameroon rainforests (300 - 2300 m a.s.l.) and to analyse distribution of species diversity, species turnover, elevational ranges and relationships between elevational distribution of species and their range size, body weight or diet type. Species richness on the elevational gradient of Mt. Cameroon decline monotonically with some plateau at 600 - 1000 m a.s.l. Changes of community composition along the gradient are caused mainly by species turnover at low elevations, which contrast to pattern above 1200 m a.s.l. where the betadiversity is influenced mainly by continual species loss (nestedness). Species elevational ranges increase with increasing elevation, which is in agreement with elevational Rapoport's rule. Species breeding at higher elevations have smaller geographical ranges, restricted to isolated islands of montane rainforests. Numbers of insectivorous species are rapidly decreasing with increasing elevation, proportion of nectarivorous species is rather invariable and number of granivorous species...
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