|
|
Factors affecting success of eradication campaigns of invasive plant species
Novotná, Tereza ; Pergl, Jan (advisor) ; Jandová, Kateřina (referee)
Increasing trade and human movements are responsible for species exchange at large scale causing several negative effects on biodiversity and human socio- economy. Introductions of new species outside their native range by humans, represents the first step in the process of biological invasions. One of the key questions related to biological invasions is how the impact of alien species can be minimized and what are the most efficient ways of management. My work is aimed to collating various information on management of invasive species in Prague, Czech Republic with special focus on identification of how many financial resources are invested to eradications, which species are being managed, and which factors affect the output of management. Several studies have identified key factors that affect the success of eradication campaigns: the spatial extent of the infestation, the reaction time, and the level of biological knowledge of the organism. Socio-economic factors, including the resources invested to eradication, are rarely available, and their effect is therefore seldom evaluated.
|
|
|
Interactions between plants and soil biota and effect of energetic crops on these interactions
Heděnec, Petr ; Frouz, Jan (advisor) ; Pergl, Jan (referee) ; Mortimer, Simon (referee)
My PhD thesis is focused on study of plant-soil interactions. Chapter 1 is focused on general introduction to the interactions between plants and soil biota in terms of relationships between soil organisms and aboveground biomass as well as root biomass. Chapter 2 is focused on food interaction of Folsomia candida and soil microscopic fungi (Penicillium chrysogenum, Penicillium expansum, Absidia glauca, and Cladosporium herbarum). Fungi were grown separately on Petri dishes or on different litter type (oak, alder and willow) separately as well. Laboratory experiments showed that food preference was more influenced by different litter types than fungal species. In chapter 3 was studied long-term production of hybrid sorrel and its effect on the composition of the soil meso and macrofauna, basal soil respiration, microbial biomass and composition of cultivable fraction of soil microscopic fungi in comparison with oilseed rape and cultural meadow. There was found that long-term production of hybrid sorrel affects the composition of soil fauna, while the microbial activity of the soil was more affected by agriculture practices, especially tillage. In chapter 4 was studied the effect of native (Salix viminialis and Phalaris arudinacea) and introduced (Reynoutria sachalinensis, Silphium perfoliatum and...
|
|
|
Study of ecosystem impact of giant hogweed (Heracleum mantegazzianum) invasion
Hladík, Marek ; Pergl, Jan (advisor) ; Hadincová, Věroslava (referee)
The present study deals with ecological impact of giant hogweed (Heracleum mantegazzianum) invasion in Slavkovský les area. Being one of the prominent invasive species with significant impact on human health it has been subjected to a wide research. In spite of that little is known about its impact on the invaded ecosystem. My research was therefore focused on analysis of the ecosystem impact, particulary 1) microclimatic measurements of temperature and soil moisture and their comparisons between invaded and noninvaded vegetation, 2) comparison of germination and survival of model plant species sowed into invaded and noninvaded plots and 3) study of the effect of H. mantegazzianum presence on model species seed production. Results have shown significant alteration of microclimate due to H. mantegazzianum invasion. Further research is needed to resolve what impact it may pose to species in invaded communities. The effect of Heracleum mantegazzianum presence on germination and survival of model species was not significant. Similarly, seed production of model plants was not significantly affected.
|
|
|
Succisa pratensis and impacts of herbivores on individual fitness
Janovský, Zdeněk ; Pergl, Jan (referee) ; Münzbergová, Zuzana (advisor)
Zdeněk Janovský Succisa pratensis and impact of herbivores on individual fitness In this master thesis I tried to examine the impact of three herbivore groups on both short- term and long-term fitness of Succisa pratensis individuals. Concretely I studied these three herbivore groups: (i) folivores; (ii) stalk grazers; and (iii) seed predators. The impact of folivores and stalk grazers was studied in a four-year study on repeatedly censused individually marked S. pratensis plants on six sites. The impact of seed predators was studied in a separate experiment. Stalk grazers and seed predators have a direct negative influence on short-term plant fitness. However, the impacts of stalk grazing were offset by affected plants by means of increased long-term flowering probability. On the other hand folivores have a long-term negative effect on plant reproductive effort despite their short-term positive influence on survival and clonal reproduction. Probable explanation of this observed phenomenon could be due to the influence of folivores on reproductive effort of the plants already in the year of their occurrence. The impact of seed predators is very variable, although higher plants suffered from higher proportion of destroyed seeds. A conceptual model of possible impacts of these three herbivore groups on...
|
|
| |
|
|
Methods of mapping and monitoring invasive (selected alien) species - monitoring
Pergl, Jan ; Dušek, J. ; Hošek, M. ; Knapp, M. ; Simon, O. ; Berchová, K. ; Bogdan, V. ; Černá, M. ; Poláková, S. ; Musil, J. ; Sádlo, Jiří ; Svobodová, J.
The project aims at problematic invasive species and their prioritization. In the methods we define several groups of aliens for monitoring. In the project are shown the rough financial costs.
|
|
|
Methods of mapping and monitoring invasive (selected alien) species - mapping
Pergl, Jan ; Dušek, J. ; Hošek, M. ; Knapp, M. ; Simon, O. ; Berchová, K. ; Bogdan, V. ; Černá, M. ; Poláková, S. ; Musil, J. ; Sádlo, Jiří ; Svobodová, J.
The project aims at problematic invasive species and their prioritization. In the methods we define several groups of aliens for mapping. In the project are shown the rough financial costs.
|
|
| |
|
| |
|
| |
guest ::
