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The relationship between spatial scaling of biodiversity and the number of individuals
Dlouhá, Hana ; Storch, David (advisor) ; Šizling, Arnošt Leoš (referee)
The patterns connected with increasing number of species while enlarging studied area (species-area relationship, SAR) remained one of the most studied topics in ecology. In the past, papers presenting single SAR curves prevailed. Recently, also unifying works have appeared. One approach has focused on the possible relationship between mean number of individuals per species and the rate of increase of number of species with area. According to this theory higher mean species abundance leads to lower values of SAR curve slope. Moreover, there is one prediction based on maximization of entropy principle (MaxEnt) that is able to give us particular values of SAR's slope when we provide the values of mean species abundance. There are also other approaches except for MaxEnt one that deals with mean species abundance and reached similar results. The main aim of this work was to gather all possible data about slopes of SARs and mean species abundances and find out possible relationships between these two variables. I have also included several other variables into the analyses to reveal the importance of them as predictors for the values of the slope. I performed two main groups of analyses. At first I focused on overall slopes of SAR curve (overall slope represents the slope of a line that resulted from...
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The relationship between diversity patters, spatial distribution and life-histories in African birds
Tószögyová, Anna ; Storch, David (advisor) ; Šizling, Arnošt Leoš (referee)
Species with particular traits are not randomly distributed across landscape. Habitats provide the templet on which evolution forges characteristic morphologies and life-history strategies and environmental determinants in an ecological processes represent a filter for certain species with appropriate traits. It is essential to understand how spatial differences in community composition are affected by geographical patterns in a distribution of species characteristics. I was interested in searching and determining the relationships between species traits and environmental parameters within avifauna of south Africa. I investigated the effect of which variables of environment most influenced bird assemblage composition and distribution of species traits in space. Relationships between the environmental factors and the species traits and life-history stategies were investigated using RLQ analysis, a multivariate ordination method able to relate a species trait table to an environmental table by way of a species presence/absence table. The first axis of the RLQ analysis was highly statistically significant and explained most of the variability. It was strongly positively related to increasing productivity, to atributes reflecting vegetation character and to availability of water sources. The rest of...
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Links between nest positions and intraanual dynamics of Blackcaps’ territories.
Vojtěchovská, Eva ; Šizling, Arnošt Leoš (advisor) ; Sedláček, Ondřej (referee)
This diploma theses intention is to study territory dynamics and it's relationship to parameters of territories, position of nest and reproductive success of blackcap (Sylvia atricapilla). I assumed, that parameters of territories are depended on breeding phases and on intraspecific interaction with neighbours and conversely, that position of nest is depended on the territory parameters. The research of territory dynamics was performed in a nature preserve Lipovka (14,6 ha) in breeding seasons of years 2006 and 2007. Main method of the research was mapping territories of blackcaps, based on registrations of colour-marked males (territory owners) and finding and observation of nests. On all found nests we noted their position on the locality, progress of breeding, breeding size and success and nest concealment. During two breeding seasons we catched and colour-marked 58 individuals. In 2006 we mapped 25 pairs of blackcaps, which were breeding and we found 30 nests of which 13 were successful. In 2007 22 pairs were breeding and we found 33 nests of which 14 were successful. Results have shown, that male territory parameters are influenced by passing breeding phase. So, male's territory, is greatest in before and after breeding phases, whereas the size significantly decreases through egg phase to nestling...
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