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Prediction of invasive marbled crayfish (Procambarus fallax f. virginalis) global spread
Nováková, Pavla ; Patoka, Jiří (advisor) ; Antonín, Antonín (referee)
Biological invasions are currently a global problem. They often cause a loss of biodiversity and severely disrupt the balance of entire ecosystems. One of the most dangerous among the many species of crayfish known to be invasive is the marbled crayfish or Marmorkrebs (Procambarus fallax f. virginalis Martin et al., 2010).
The marbled crayfish is a major ornamental crayfish species. It is a known vector of infectious crayfish plague, which is lethal for crayfish species of non-North American origin. Marbled crayfish is also very tolerant to different water temperatures. The most important feature making it an especially dangerous invasive species, is the way of its reproduction. Marbled crayfish reproduces via apomictic parthenogenesis. Therefore, only females are able to reproduce and males of this taxon has not been recorded. This crayfish is characterised by a very quick maturation and extremely rapid growth.
Even though some established populations of this taxon in the wild have already been recorded, and probability of the establishment in selected regions was evaluated, no predictions for expansion on a global scale have been conducted.
The program CLIMATCH was used in this thesis to match the climate conditions between the source area (distribution of established populations of marbled crayfish in the wild) and target areas (all continents excluding Antarctica) based on temperatures during the coldest and warmest quarters of the year.
The results showed that marbled crayfish can probably survive and reproduce in even colder regions of the temperate zone. The presented findings additionally indicate that temperate zones contain slightly higher potentially suitable regions than in the case of tropics. There are temperature conditions most suitable for the survival and reproduction of the marbled crayfish within Europe in comparison of the rest of the world; and the least favourable temperature conditions are within Australia.
The marbled crayfish introduction and ability to survive and reproduce in the wild is a potential threat to native biota and entire ecosystems on all continents assessed. Therefore, it is strongly recommended that the breeding of and the pet trade with this crayfish should be regulated by policymakers and wildlife managers by improvement of legislative restrictions (such as in the EU) and intensive future education of general public. It is obvious that the monitoring of invasive crayfish species might be continuous. Nevertheless, the most important step is to make producers and hobbyists aware of the risks related with marbled crayfish.
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Growth and environmental effects of Grand fir cultivation in conditions of the Czech republic
Fulín, Martin ; Podrázský, Vilém (advisor) ; Antonín, Antonín (referee)
Grand fir (Abies grandis /Douglas ex D. Don/ Lindl.) is a species with potential benefits for the implementation of many functions in forest management: namely the function of production, soil improvement, stabilization and landscaping. It was introduced to the Czech Republic, as well as to other European countries, since the first half of the 19th century, mainly by aristocratic families. First plantings were performed in the parks, but gradually also in the forest stands. Another wave of interest in this tree species was associated with the decline of the domestic silver fir (Abies alba Mill.). It was to some extent substitute, for this period comes the greatest number of plantations in the country. The aim of this thesis is, therefore, monitoring of growth and production of the grand fir, but also the evaluation of the effects on the basic characteristics of the soil chemistry, nutrient dynamics and possible degradation effect on forest lands. Research areas were mainly located in the University Forest Enterprise Kostelec nad Černými lesy, but also in other places such as Hrubá Skála at Turnov, forests owned by Kinský at Žďár nad Sázavou and Kynšperk nad Ohří. Monitoring was carried out on already established and monitored middle-aged permanent plots (35 to 55 years), which were assessed at mensurational parameters (position, height, diameter at breast height, ratio of the green crown), in further the quantity and quality of forest floor and upper mineral soil components was studied. This work also contains the measurements of the provenance plot of Forestry and Game Management Research Institute. The results show that the grand fir is a productive tree species that exceeds the stock of domestic conifer tree species and its intensive growth is comparable with Douglas fir. From the perspective of provenance trials is crucial the correct choice of provenance, which achieves better yields and quality of wood. Best provenances come from the island Vancouver and the coast of Washington state. At the soil analysis reaching grand fir better values in comparison with Norway spruce and got it closer to the values of broad-leaved tree species. Thus it can be said that grand fir represents important soil-improving and stabilization tree species.
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Environmental risk assessment of ornamental aquaculture
Patoka, Jiří ; Kalous, Lukáš (advisor) ; Antonín, Antonín (referee)
The ornamental aquaculture comprises both outdoor and indoor keeping of aquatic animals and plants for ornamental purpose which is a very popular hobby with many followers worldwide. It is also commercially profitable for specialized producers and vendors. Associated environmental risks include particularly introduction of non-native species, biological invasions and intensive field capture of exploited and marketed species. Since subsequent regulation, mitigation and eradication of naturalised alien species is very difficult and ineffective in many cases, the most important above all is to prevent new introductions. This trend is accented with a short delay in European legislature. The European Union (EU) currently initiates formation of list of the most invasive alien species. Although invasive potential of certain ornamental species such as red-eared slider (Trachemys scripta elegans) is well known, the vast majority of traded species has never been tested and analysed from this point of view. Publications attached to this thesis are focused on monitoring and survey of market with ornamental animals, such as fishes and crayfishes, with special emphasis on list of advertised species, size classes, prices, origin and availability on market. With use of predictive models the probability of naturalisation and potential invasiveness of mentioned ornamental species were estimated. These information are supported by analysis of hobbyist behaviour. Results in present thesis highlight known environmental risks associated with ornamental aquaculture and also show detailed information about overlooked risks from the Czech Republic's as well as from EU perspective. Therefore this thesis should to help formation of aforementioned list of the undesirable species.
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Agroforestry Systems in Czech Republic
Zelba, Ondřej ; Lojka, Bohdan (advisor) ; Antonín, Antonín (referee)
Temperate agroforestry has been described and categorized several times and there are numerous definitions in use. Even though several agroforestry practices have been traditionally used in Czech Republic, any inventory of farms or plots where agroforestry is currently practiced is still missing. This study aimed to find a practical and relatively easy method to identify agroforestry systems on farmland. Firstly, several European surveys such as Land Use and Cover Area Frame Survey (LUCAS) and Corine Land Cover (CLC) were examined to evaluate their applicability in inventory of agroforestry, and several methods of identifying trees in agricultural land blocks were reviewed. The thesis tried out a method that uses Corine Land Cover data in ArcGIS software to identify out patches of land that fall into the annual crops with permanent crops category. It then found agricultural land blocks with trees in those polygons. In the last part of the study, farmers owning plots in the agroforestry field blocks were located in the land registry and a questionnaire was sent out to them regarding the origin, function, and use of the trees in the agricultural blocks to collect information about the land-use systems. In total 3,071 hectares of field blocks were identified to fit the agroforestry conditions, mostly in the South Moravia region. Most of the found areas are in proximity of towns Velké Pavlovice, Louka u Ostrohu, Strážnice na Moravě, Moravský Žižkov, and Šakvice. The areas found there have many small plots that are each owned by a different owner, which creates a very heterogenous landscape. The area is well known for its fruit orchards and the questionnaire answers confirm that the area is indeed suitable for trees like apricots and cherries. The answers have also shown that the agricultural production directly neighboring with the trees used to be much more varied in the past. The thesis also reviewed legislative options for the support of agroforestry and suggested an improved ruleset to determine if a land-use system should be supported by subsidies for agroforestry systems.
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