Since the beginning of the 20th century human land use changed drastically in Central Europe. These changes included: homogenization of the landscape mosaic, intensification of agriculture, urbanization and land abandonment. In turn, these changes affected bird species and perhaps most significantly manifested in population decline of open habitat birds. Therefore, it is important to investigate sites, which were not affected by the changes mentioned above, such as military training areas (MTAs) - places dedicated to training of armed forces. Previous studies have shown that MTAs seem to host remarkably high bird diversity and abundant populations of bird species of conservation concern. This may be caused by two major factors. First, closure of MTAs to all human activies besides military training spared them of the landscape changes mentioned above. Second, the military training itself produces a very heterogeneous habitat mosaic that allows coexistence of many species with different ecological requirements. To my knowledge, no study compared bird assemblages between MTAs and surrounding landscape directly. At the same time, such data are crucial to assess the value of MTAs for bird conservation reliably and, as a consequence, they enable to think more deeply about mechanism generating this value....

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L’objectif de ce mémoire est de déterminer si l’unicité écologique des communautés végétales est un critère approprié pour prioriser l’allocation des efforts de conservation dans les milieux humides lacustres. Pour répondre à cette question, j’ai utilisé des données d’inventaire végétal dans deux emplacements géographiques situés dans le sud du Québec et pour trois types de milieux humides (i.e., frênaies, aulnaies, tourbières). J’ai d’abord identifié les milieux humides statistiquement uniques en calculant leur contribution locale à la diversité bêta (LCBD). J’ai ensuite mesuré le degré d’association relatif entre les valeurs d’unicité écologique et plusieurs autres critères couramment employés pour déterminer les priorités de conservation, et ce, à l’aide de corrélations de Pearson et de partitionnements hiérarchiques. Les tourbières uniques avaient une grande valeur de conservation dans les deux régions étudiées, alors que les aulnaies et frênaies uniques montraient des signes d’altération de leur composition en espèces. La composition en espèces des sites uniques devrait donc être examinée pour en déterminer la valeur de conservation, puisqu’elle pourrait être affectée par le niveau d’intégrité du paysage. La proportion d’espèces rares ainsi que la présence d’espèces spécialistes sensibles aux perturbations étaient corrélées de façon importante et congruentes avec l’unicité dans les deux régions étudiées. Au contraire, la richesse spécifique était négativement corrélée avec l’unicité, ce qui suggère la nécessité d’un compromis. Une combinaison de critères complémentaires devrait donc être utilisée en plus de l’unicité afin d’identifier l’ensemble optimal de sites à protéger dans un contexte donné. / This study aimed to determine whether plant composition uniqueness is an adequate criterion for assessing conservation priorities in lake-edge wetlands. To answer this question, I used vegetation data from two large datasets of lake-edge wetlands located in southern Québec, which encompassed three wetland types (i.e., ash-dominated swamps, alder-dominated swamps, peatlands). I first identified statistically unique wetlands by computing their local contribution to beta diversity (LCBD). I then measured the relative association between ecological uniqueness values and other criteria commonly used to assess conservation priorities using Pearson correlations and hierarchical partitioning. Unique peatlands had a high conservation value in both study regions, while ash- and alder-dominated swamps showed more signs that their species composition had been altered. The species composition of unique sites should thus be examined closely to determine its conservation value, as it could be affected by the overall integrity of the landscape. The proportion of rare species and the presence of disturbance-sensitive specialist species were appreciably correlated and congruent with uniqueness in both study regions. On the other hand, species richness was negatively correlated with uniqueness, suggesting that there was a trade-off. A combination of complementary criteria should therefore be used in conjunction with uniqueness in order to identify the optimal set of sites to protect in a given context.

Light is essential component of forest ecosystem, as limited light availability in forest-floor restricts herb and tree seedlings growth. Importance of light availability for maintaining plant species diversity and community structure wasn't sufficiently evaluated in the Czech Republic. This study focus on the ecological relevance of light availability on both landscape and local scale. Relationship of light to cover, diversity and species composition was quantified in the thesis. Dominant tree species affected light availability and its spatial variability. Light availability was along the soil reaction and slope most influential factor for large-scale species diversity. Within-site light variability affected plant diversity more than soil reaction variability. Measuring light by means of hemispherical photography seems to be an appropriate for studies like this. Light availability influnence on community compostition is weak in comparison with other environmental gradients.

Semi-natural grasslands of the eastern Moravia have big potential to host species-rich plant communities. However, changes in land-use during the second half of the last century were rapid and vast and many grasslands had been ploughed over. In the early 80s some arable lands were sown with low diversity clover-grass mixture and transferred back to grassland. Restoration of grasslands on former arable fields is a major challenge. Their colonisation by grassland species may be complicated by initial seeding productive low diversity seed mixtures. The aim of this study was to estimate differences in species composition and species diversity between ex-arable artificially seeded grasslands and fragments of grasslands with continuity over 70 years in the north part of White Carpathian Mts., SE Czech Republic and identify species traits limiting species ability to colonize the ex-arable grasslands. Target plant species (total of 137) were surveyed on 66 grasslands. Surveyed grasslands were according to continuity and type of management. Coordinates of centroids from each polygon (i. e. surveyed grassland) were used to treat the spatial correlation of the surveyed grasslands. The effect of continuity on species composition and diversity was tested after accounting for differences in the management and...

This thesis is the first of its kind that evaluates the species composition, species richness and species abundance of zooplankton in littoral samples of 90 Tatras lakes (Western and High Tatras of Slovakia and Poland) collected in September 2004 in the context of environmental parameters of lakes and spatial relationships of individual lakes. The most frequently occurring species in the Tatras lakes in 2004 were also evaluated in terms of their occurrence in the lakes a century ago (Minkiewicz 1914, 1917 and Lityński 1913, 1917), during the period of acidification (Ertl & Vranovský 1964, Ertl et al. 1965, Hrbáček et al. 1974, Stuchlík et al. 1985) and during the period of recovery of the lakes from acidification (Hořická et al. 2006, Sacherová et al. 2006). Relationships between variables were analysed using Poisson regression, cluster analysis with multinomial regression, canonical correspondence analysis, Mantel tests and multiple negative binomial regression. Using analyses, lakes were divided into four clusters (A, B, C, D). Each cluster consisted of lakes with the same environmental and spatial factors and similar species composition. Thirteen zooplankton species (Acanthocyclops vernalis, Acroperus harpae, Alona affinis, Arctodiaptomus alpinus, Ceriodaphnia quadrangula, Cyclops abyssorum...

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The life of bryophytes is closely connected with their surrounding environment. Changes in atmospheric conditions on the microscale directly affect the physiological functions of bryophytes, which in turn determine their distribution. The current development of technologies allows us to measure the microclimate affecting bryophytes directly in the field. Nevertheless, there have not been many studies published examining the response of bryophytes to in situ measured microclimate. This diploma thesis is one of the first in Europe to provide data from continuous field microclimatic measurement performed on a scale relevant to bryophytes. It deals with the influence of the microclimate on the bryophyte species richness and community composition within a single gorge in the Bohemian Switzerland National Park. For 17 months, 38 HOBO Pro v2 Onset dataloggers were recording air temperature and air humidity 10 cm above the ground. I performed detailed bryological survey on two differently sized plots (circle with a radius of 1 or 2 m) around each of the dataloggers. The microclimate is influenced by the topography and character of the vegetation, therefore I derived topographical data from a digital terrain model (resolution of 1 m), calculated the canopy openness using hemispherical photographs and...

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