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The influences of biotic interactions on population biology of Sanguisorba officinalis
Větvičková, Anna ; Janovský, Zdeněk (advisor) ; Jičínská, Jana (referee)
Plants can interact with many different organisms on many trophic levels in their life. In this thesis I investigated how three biotic inertactions, powdery mildew infection, caused by Podosphaera ferruginea, predispersal seed predation by Dusky Large Blue (Phengaris nausithous) and Scarce Large Blue (P. teleius) and deer grazing affect life cycle and population biology of the Great Burnet (Sanguisorba officinalis L.). I also analysed their preferences of environmental conditions. Most of studied plant populations growth rates (λ) were lower than 1 and population decreased, but quite surprisingly for more populations vegetative reproduction was more important than reproduction by seeds. All intraction mentioned above affects more generative reproduction, and thus their influence on Great Burnet population dynamics is low, even with modelled maximal possible effect. Environment conditions analysis showed that powdery mildew occurs on sites with more flowering individuals, where spreading is very easy, butterflies preferred high, well noticeable flower heads grown high above other vegetation and host ant presence. For host ants' presence model locality was only significant variable.
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The status of Large Blue Phengaris teleius population on selected meadows in Broumovsko region
Hejretová, Kateřina ; Vrabec, Vladimír (advisor) ; Kamil, Kamil (referee)
I conducted a monitoring of Scarce large blue Phengaris teleius (Bergsträsser, 1779) by reverse capture of marked individuals method on 13 examined meadows in Broumov area near Ruprechtice, Hyncice and Vižňov in the period from 4th July to 5th August of 2016. I marked a total of 409 butterflies of this species. Data were evaluated with the help of software MARK 8.1 and the total number of butterflies metapopulation was estimated at 802 individuals, whereas the estimates of quantity for each area ranged from 2-269 specimen. I registered most of the individuals at the Ruprechtice 2 station.
I documented the flyovers of P. teleius individuals between stations within a Ruprechtice Hynčice area. I consider the involvement of Vižňov as realistic, but due to the local total number of butterflies, the detection of P. teleius flyover failed. I consider the hypothesis formulated in the objectives of the work: All the examined areas communicates via overflights of the butterflies and the system can be considered as a single metapopulation, as confirmed.
I consider as important a finding that there still lives a stable population of Phengaris teleius and P. nausithous butterflies in Broumov area. The numbers of these butterfiles are in hundreds to thousands of individuals, and it is important to remember that this is only the population of examined areas, not all areas of occurrence of blue butterflies in stated territories. Those numbers after the first year of observation are unknown. The layout of examined colonies is beneficial for targeted protection planning. The metapopulation model continent islands is not the case of stations examined by myself.
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Influence of meadow management on the migration behavior of selected species of butterflies
Bubová, Terezie ; Langrová, Iva (advisor) ; Farkač, Jan (referee)
Migrations are the key process and one of the basic biological features, which allow survival of endangered species in fragmented landscape. In the last decades, agriculture intensification, industry and urbanization caused that number of natural butterfly habitats has significantly decreased. The localities originally suitable for butterflies are currnetly converted to farmland or building plots. This PhD thesis aimed to find a compromise solution of meadow management, which should allow a commercial use and concurrently do not jeopardize the continued existence of endangered or threatened species. The main idea of this study was in the intentional emigration causing in the middle of flight period, which should lead into resettlement of the population to another (potentially more suitable) locality. Possibility of aimed manipulation with butterfly emigrations would be considered as a major breakthrough in their protection.
The investigated species Phengaris nausithous (Bergsträsser, 1779) and Phengaris teleius (Bergsträsser, 1779) are both considered to be flagship species for protection of European butterflies at open meadows. This study is based on research, which was carried out in 2013-2015 at 17 patch in localities Dolní Labe, Czech Republic. In above mentioned years, one selected meadow was mowed in the middle of flight season and the emigrations were then monitored using mark-release-recapture method. Results of population and migration characteristics were calculated in MARK 8.1 software. Subsequently, the effect of mowing on emigration (comparison of emigrations from the meadow before and after mowing) was evaluated using Statistica 13.
The hypotheses of this study were based on the assumption, that the loss of resources after well-timed mowing should increase the activity of adult butterflies. During the monitoring, number of emigrations was increased only in flight season 2015. Unfortunately, the statistical evaluation did not show significant effect of mowing on migrations. On the other hand, the hypothesis dealing with colonization of nearest meadows was confirmed.
Effect of intentional emigration caused by management interventions was unfortunately not proved. However, we found out, that even though the population at one mowed meadow decreased clearly, the metapopulation size at the locality remained more or less stable.
At investigated (mowed) meadow, there was observed a sharp decline of P. nausithous abundance. On the other hand, P. teleius population was only slightly reduced. It is therefore conceivable, that P. teleius are not as susceptible to innapropriate term of mowing. The results obtained in our research conclusively displayed no possible positive effect of mowing in the middle of flight season and a necessity of suitable management maintenance at localities inhabited by Phengaris butterflies.
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