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Coexistence of plant species in fragmented landscape
JANEČKOVÁ, Petra
Semi-natural grasslands are hotspots of biodiversity in the present-day landscape. The thesis focuses on various effects and processes affecting plant species coexistence at two different scales. At the local scale, the effects of management and fertilization were assessed in relation to abiotic gradients and species functional traits. At the landscape scale, the patch spatial configuration, land use and plant functional traits may influence species distribution. The diversity pattern in fragmented landscape is also modified according to availability of suitable patches and landscape heterogeneity.
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Functional diversity in ecological communities
Džamba, Roman ; Hořák, David (advisor) ; Doležal, Jiří (referee)
Functional diversity is an important component of biodiversity. Value and range of functional traits and the number and composition of functional types are crucial for the short and long term functioning of ecosystems. Functional traits of species affect their performance in ecosystems and we can classify them as continuous or discontinuous. It has been suggested many ways to choose the appropriate traits and functional differences between species in estimating functional diversity. It is necessary to consider the nature and importance of ecosystem processes and environmental factors and consider properties of employed methodological approaches. There are many ways to estimate functional diversity. Functional diversity can be expressed by the number of functional groups, functional index or functional dendrograms. In natural communities, we see a positive relationship between species and functional diversity. Species diversity doesn't seem to be an adequate surrogate for functional diversity because the loss of an equal number of species may have different effects on the ecosystem, depending on the identity of the species. Functional redundancy refers to the functional similarity in the ecological niches occupation and is a source of stability in the ecosystem functioning.
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Functional diversity in ecological communities
Džamba, Roman ; Hořák, David (advisor) ; Doležal, Jiří (referee)
Functional diversity is an important component of biodiversity. Value and range of functional traits and the number and composition of functional types are crucial for the short and long term functioning of ecosystems. Functional traits of species affect their performance in ecosystems and we can classify them as continuous or discontinuous. It has been suggested many ways to choose the appropriate traits and functional differences between species in estimating functional diversity. It is necessary to consider the nature and importance of ecosystem processes and environmental factors and consider properties of employed methodological approaches. There are many ways to estimate functional diversity. Functional diversity can be expressed by the number of functional groups, functional index or functional dendrograms. In natural communities, we see a positive relationship between species and functional diversity. Species diversity doesn't seem to be an adequate surrogate for functional diversity because the loss of an equal number of species may have different effects on the ecosystem, depending on the identity of the species. Functional redundancy refers to the functional similarity in the ecological niches occupation and is a source of stability in the ecosystem functioning.
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Land Abandonment in the Mediterranean Effects on Butterfly Communities with Respect to Life History Traits
ŠLANCAROVÁ, Jana
This thesis deals with the effects of changing land use, following landscape abandonment, on butterfly communities in the Mediterranean Basin. It consists of three case studies. The first focuses on the effects of forest encroachment on butterflies in the Southern Balkans; the second studies butterfly communities in Portuguese 'montados' and the third explores demography and life histories of three co-occurring Papilionidae butterfly species (Archon apollinus, Zerynthia polyxena and Zerynthia cerisy) in Greek Thrace. The results describe shifts in butterfly communities, detectable even at the level of individual species life history traits, with increasing forest encroachment. The preference of range-restricted Mediterranean endemics for either grasslands or open woodland formations contributes to falsifying the forested Mediterranean hypothesis, favouring a hypothesis of finely grained landscape mosaic instead. This mosaic is currently threatened by land use change and biodiversity homogenisation. Maintaining habitat and landscape heterogeneity is crucial for conserving the Mediterranean biodiversity hot-spot.
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