National Repository of Grey Literature 12 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Community structure of caterpillar parasitoids from tropical rain forest
LIBRA, Martin
The aim of this dissertation is to investigate the community structure of parasitoids and their interactions with their hosts - caterpillars in the rainforest of Papua New Guinea, focusing on beta diversity and altitudinal trends. We show that parasitoid beta diversity is higher than the beta diversity of their hosts, which was also projected in their interactions. The altitude plays important role in the diversity of parasitoids, where we show that Ichneumonidae are more diverse at high elevation than at low elevation, which was not observed for other large insect families. Further, we performed a manipulative experiment, exposing live caterpillars in different elevations of tropical rainforest. Caterpillars faced similar mortality from parasitoids between elevations, but higher mortality from predation at low elevation. In the last chapter, we point out how important is correct species identification because wrong identification can misinterpret observed interactions.
Changes in ladybird communities along an altitudinal gradient
Matušová, Martina ; Kindlmann, Pavel (advisor) ; Martínková, Zdenka (referee)
Ladybugs are often used in biological control, because of their predatory way of life and potential ability to control many insect pests. So far, a number of studies was performed on this family, on their hunting strategies, other life history strategies, population dynamics, dependence of their distribution in time and space on the abundance of prey etc. However, the temporal changes in species composition and relative or absolute abundance of ladybugs were not yet examined along an altitudinal gradient. This is why I have focused my work on these dependencies. I tested the following hypothesis: overwintering sites in Coccinellidae are usually located at lower altitudes, where the individuals eventually attack their prey on the earliest budding trees; as season goes on, ladybugs follow the trends in environmental conditions and food and move to higher located sites; at the end of the season, ladybugs return back to their overwintering sites. In the research area in the Beskydy Mountains, 12 experimental sites were selected, evenly spaced along an elevational gradient of 350-482 m above sea level at each location. During the season, 12 measurements at two-week intervals were performed, each containing 2x300 sweeps. A total of 3064 of ladybug individuals were collected, belonging to 11 species. The...
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...
Geographical distribution of Piciforms' abundaces in Smrčina area, Šumava National Park
Souček, Michal ; Hořák, David (advisor) ; Riegert, Jan (referee)
The geographical distribution of Piciforms' is one of the factors indicating the state of the forest. These forest birds are bioindicators of climax forest communities. In Šumava National Park, some of the Piciforms' are flag species' and thanks to that, various historical data about them exist. The goal of my study was to evaluate data from 2006-2018 monitoring and add my own monitoring data from years 2019 and 2020. This data consists of location of individual birds living in the region called Smrčina, the southernmost point of the National Park. The goal of this thesis was to determine which factors influence the distribution. The method chosen for the monitoring was so called "point count method", used from the beginning of April till the end of June. For the statistical analysis, the R software was used. And for the visualization of geographical distribution, I used qGis. The result of my thesis is that from 10 Piciform species living in the Czech Republic, 8 live in the studied region. The abundance of Black Woodpecker and Great-Spotted Woodpecker from year 2006 and Three-Toed Woodpecker from year 2009 is stable. (Great- Spotted Woodpecker with 1,6, Black Woodpecker with 0,5 and Three-Toed Woodpecker with 0,8 pairs on one hectare.) The most rare species White-Backed Woodpecker was spotted...
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
Breeding and singing activity of rainforest birds along an elevational gradient in tropical Africa
Zenklová, Tereza ; Sedláček, Ondřej (advisor) ; Riegert, Jan (referee)
Tropical areas are usually expected to be a stable environment when compared to the temperate zone. This is true especially for the temperature and the day length which ensure relatively stable food supply. As a consequence, tropical birds, especially rainforest species, are thought to breed all year round. But even in the tropics, breeding can be synchronized with some fluctuating environmental conditions such as rainfall and differences in food supply and breeding and singing activity may occur seasonally in tropical rainforest as well. But the data for testing these assumptions are still scarce. In the first part of my thesis, I focused on the seasonality in breeding activity in various feeding guilds of birds inhabiting tropical rainforest on Mount Cameroon in three different elevations - lowland, submontane and montane forest. The second part focuses on the seasonality in singing activity at both population and species level. I also compared singing activity with the data on breeding activity. The extent of breeding activity differed between feeding guilds and I showed preferences of different guilds to different seasons for breeding. Most of the groups, especially insectivorous birds, bred in the beginning of the dry season, except of species searching for invertebrates on the ground. These...
Changes in ladybird communities along an altitudinal gradient
Matušová, Martina ; Kindlmann, Pavel (advisor) ; Martínková, Zdenka (referee)
Ladybugs are often used in biological control, because of their predatory way of life and potential ability to control many insect pests. So far, a number of studies was performed on this family, on their hunting strategies, other life history strategies, population dynamics, dependence of their distribution in time and space on the abundance of prey etc. However, the temporal changes in species composition and relative or absolute abundance of ladybugs were not yet examined along an altitudinal gradient. This is why I have focused my work on these dependencies. I tested the following hypothesis: overwintering sites in Coccinellidae are usually located at lower altitudes, where the individuals eventually attack their prey on the earliest budding trees; as season goes on, ladybugs follow the trends in environmental conditions and food and move to higher located sites; at the end of the season, ladybugs return back to their overwintering sites. In the research area in the Beskydy Mountains, 12 experimental sites were selected, evenly spaced along an elevational gradient of 350-482 m above sea level at each location. During the season, 12 measurements at two-week intervals were performed, each containing 2x300 sweeps. A total of 3064 of ladybug individuals were collected, belonging to 11 species. The...
The changes of species composition of soil phototropic microorganisms on the altitude gradient in E Ladakh
Janatková, Kateřina ; Němcová, Yvonne (advisor) ; Hrouzek, Pavel (referee)
Abundance and diversity of microbial phototrophic communities (cyanobacteria and eukaryotic microalgae) were investigated at two localities in main mountain ranges of Ladakh (Tibetan Plateau and Eastern Karakoram), India. Samples were collected along a two representative altitudinal gradients at each locality (E Karkoram 4620 - 5100 m asl., Tibetan Plateau 5346 - 5833 m asl.) in alpine and subnival zones in the vicinity of cushion plant Thylacospermum caespitosum (Caryophyllaceae). At each altitude 6 soil samples were taken from below cushion and 6 samples from outside the cushion. The epifluorescent microscopy and DGGE-method were used to determine diversity and biomass of phototrophs in the studied soils. Physico-chemical analyses (pH, texture, organic matter, nitrogen, ammonia and phosphorus content, concentration of chlorophylls and carotenoids) were also performed on the samples. The effect of altitude, mountain ranges and T. caespitosum on the composition and biomass of phototrophs and physico-chemical parameters of soil was tested by multivariate redundancy analysis and variance partitioning procedure. This study shows that the semiarid and arid soil of high elevation in Ladakh Mts. is suitable place for the development of microbial phototrophic communities and is important part of the ecosystem. The...
Population structure and dispersal of butterflies in tropical rain forests of Papua New Guinea
VLAŠÁNEK, Petr
The thesis describes the community composition, population structure and dispersal in a lowland rainforest community, extended to changes in butterfly composition along an altitudinal gradient. It tests the feasibility of mark-release-recapture studies in the understories of lowland primary forests, describes dispersal in relation to host plants and compares dispersal and demographic parameters with temperate species. Focusing on primary as well as secondary sites the thesis analyzes species richness and similarity between sites along an altitudinal gradient. It also tests ecological correlates for endemism in New Guinea butterflies, particularly their geographic and altitudinal range, as well as their optimum altitude.
Dendrochronology of representative autochtonnous tree species on environmental and temporal gradients
ČEJKOVÁ, Alžběta
This thesis is focused on application methods of dendrochronology on various ecological and historical aspects of forest communities, human management practices, and historical utilization of wood. Studies revealed growth responses of trees in various type of forest vegetation represented by spruce forest, alder carr and alluvial forests and involved autochthonous tree species with all morphological types of wood. These works demonstrated necessity of dynamic evolving of the regional chronologies for the Czech Republic.

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