National Repository of Grey Literature 69 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Factors affecting farmland bird abundance in different European regions
Bystřický, Václav ; Reif, Jiří (advisor) ; Hořák, David (referee)
Farmland is a very important habitat for many open-habitat bird species. It serves as a food source as well as a breeding and wintering ground. In recent years, however, there has been evidence of population decline in some of these species. This decline is caused by various factors linked to human activities. The aim of this work is to summarise these negative factors and create a comprehensive overview of farmland bird populations status in different parts of Europe. I found that in comparison with other parts of Europe, a much more significant population decline of farmland birds occurs in western and northwestern Europe, mainly due to more intensively cultivated landscapes over the last decades. Central and Eastern European countries are less affected as they show lower intensity of land use associated with numerous small farms as well as the cultivation of spring cereals. In contrast, the abandonment of farmland may be one of the most threatening factors for the whole Mediterranean region. From the perspective of biodiversity conservation, one of the possible solutions could be a lower application of different types of pesticides, cultivation of various kinds of crops or longer- lasting stubble fields. Key words: farmland, birds, biodiversity, population decline, Europe
Habitat characteristics accounting for the attractiveness of military training areas for birds: a case study from the Hradiště military training area
Hernová, Jana ; Reif, Jiří (advisor) ; Vojta, Jaroslav (referee)
Military areas are extraordinary biodiversity-rich due to limited economic activities and a specific way of using the areas for military training. Previous research has also revealed their positive influence on bird species diversity, this applies to endangered species in particular. However, the exact biotope characteristics attracting birds are insufficiently known. In this regard, I expected an important role of heterogeneity of the environment. The aim of the thesis was therefore: (I) to find out the difference of environmental heterogeneity between a military area (MA) and the surrounding landscape, both in a forest and a non-forest sites, (II) to find out what biotope characteristics attract birds in open landscape and (III) what characteristics attract birds in forest. Fieldwork took place in a still active MA of Hradiště and neighboring controls of Bochov and Ostrov. In total, 80 study plots were surveyed for representation of individual biotopes (39 types in total) and the number of fragments of woody vegetation. Data on bird species richness were taken from the thesis of Bušek (2015), surveyed birds at identical study plots and calculated total number of bird species and the number of endangered bird species at each plot. The open landscape of MA has, compared to the surrounding cultural...
Former common pastures: Biodiversity refugia in the changing landscape of Central Europe.
Vosmíková, Alžběta ; Křenová, Zdeňka (advisor) ; Reif, Jiří (referee)
The diploma thesis evaluates the current status of former common pastures of a study area in southwestern Bohemia. The thesis aims to demonstrate the high biological value of former common pastures and determine predictors of their preservation. For this purpose, a vector layer of former common pastures containing 668 segments was created. This layer was compared with other map layers (aerial images, consolidated layer of ecosystems, Natura 2000 mapping, species database) and various field observations. A database describing a current status of former common pastures was created and 49 preserved pastures were selected, according to predetermined criteria. Comparison of data from the common pastures and the sorrounding landscape confirmed higher biological value of the pastures. They have significantly higher habitat diversity, described by frequency and composition of Natura 2000 habitats. Several ecological and descriptive parameters were tested to find predictors of pastures preservation. The results showed that signifiant predictors of the pastures preservation are ecological parameters (i.e. number of Natura 2000 habitats, number of protected species recorded in database) and also descriptive factors (i.e. size of the pastures, shape, distance from municipality). Key words: common pastures,...
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
Habitat specialization as determinant of species response to the Global Change
Rivas Salvador, Javier ; Reif, Jiří (advisor) ; Riegert, Jan (referee) ; Skorka, Piotr (referee)
Human-induced global change is altering the environmental systems as we know them. Significant evidence has been acquired that suggests these changes are triggering the sixth mass extinction. This biodiversity loss seems to not be occurring at random, but it is targeting species differently according to their niche breadth. Species with a narrow habitat niche seem to be experiencing strong population decline, especially due to the intense natural habitat transformation. Therefore, we investigated the role of habitat specialization within species ecology and its conservation implications, obtaining the following key findings:  Habitat specialists gathered in montane regions and in areas with harsh climate conditions (cold and highly seasonal) across the European continent. Furthermore, we found two specialization hotspots, one in northern Scandinavia and one in the steppe region north of Caucasus. Additionally, we found that specialists and habitat generalists merge in the same communities.  Habitat specialization predicts population declines at European pancontinental scales. It brings further support for widespread process biotic homogenization, likely caused by current human-induced land use and climate changes.  When we tested whether conservation benefits of mid-field woodlots were...
Species traits and ecological conditions linked to bird colonisation of cities
Grünwald, Jan ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Human settlements are a novel habitat type and species must respond to its ongoing expansion. For effective conservation of biodiversity, it is important to understand the mechanisms underlying these responses. This thesis focuses on urbanization in birds, from both the individual and community perspectives. The aim of this thesis is to find out if there are any "pre-adaptations" in some bird species to be successful city dwellers or if all birds can potentially exploit the urban environment when local conditions allow. According to the reviewed literature, I conclude that the urbanization in birds is not a universal pattern, but there are some specific traits shared by most of the urban birds. The successful urban species are mostly omnivorous or granivorous, they breed in trees or in cavities and, they are often ecological generalists. They are sometimes represented by non-native species occurring in the cities all over the world.
The importance of woodlots and their ecological characteristics for birds in an intensively managed agricultural landscape
Rajmonová, Lenka ; Reif, Jiří (advisor) ; Šálek, Martin (referee)
Various types of woody vegetation are a key biodiversity refugee in intensively managed agricultural landscapes. However, the role of woodlots, representing an important type of such a vegetation, remains overlooked so far. Whereas the previous studies focused on the effect of their area, shape and isolation, consequences of variation in their habitat quality for biodiversity were not assessed up to now. This thesis is thus one of the first studies focusing on woodlots as a specific habitat for birds in agricultural landscape. My goals were: (I) to find out what is the bird community composition of woodlots in a Czech landscape, (II) to find out, what are the key habitat predictors of bird species richness and abundance in woodlots, (III) to describe differences in habitat preferences among various guilds and (IV) to formulate recommendations for conservational practice. I surveyed birds in 82 woodlots in an intensively managed landscape in Central Bohemia, Czechia, and measured variables describing woodlots' habitat quality together with woodlots' area, shape, isolation and types of surrounding land-use. I recorded numerous forest and non-forest bird species (57 in total), including some endangered farmland birds. The habitat variables showing significant relationships to bird community...
Bird population changes from a historical perspective: a case study from the Czech Republic
Szarvas, Filip ; Reif, Jiří (advisor) ; Koleček, Jaroslav (referee)
Numerous studies focused on the changes in breeding bird populations in the Czech Republic exist, however, these studies are based on data from 1980s onwards. Such studies investigate the effects of environmental changes on various bird groups defined by their ecological traits. Although these studies provided important insights into bird population drivers, considering the start of 1980s as a baseline for comparisons with the current conditions is questionable since the underlying drivers most likely acted for longer time. To bridge this knowledge gap, the goal of my study is to create a comprehensive dataset covering changes in bird populations over three time periods: 1950s/60s, 1980s and recent time (2014-2018) based on the memories of ornithologists who witnessed these times. The next goal is to establish whether the decrease of some species dates from the last 40 years, or whether it predates this period. The results of my study show that certain groups of birds according to their ecological requirements disappear from the Czech landscape faster than other groups. In the groups of species classified by their environmental requirements, the most rapidly disappearing are species bonded to agricultural landscape and urban species. According to the food requirements, the fastest decreasing are...

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