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On the Nothernmost and Southernmost Limits of European Land Snail Spatial Ranges
Křepelová, Lucie ; Juřičková, Lucie (advisor) ; Horsák, Michal (referee)
The aim of this work was to evaluate the limits of ranges of European land snail species along the north-south gradient. To work out the document it was necessary to prepare the set of digitalized maps, that enabled to create the database of ranges of the individual land snails species. Based on obtained data I tried to identify places where the northern and southern borders of species ranges are the most frequent. The landsnails' ranges are affected not only by particular life requirements of the individual species (potential limits), but also by other conditions, especially climatic, geographical and historical (truncated limits). In this work I focused on their differentiation. Above mentioned process also enabled me to track the north- south changes in species richness of the landsnails taking into consideration the truncated and potential limits. The most important natural barriers constraining that numerous of species cannot naturally widespread from the south to the north are the Scandinavian Mountains, the Alpes and the Carpathians and suprisingly also southern borders of german and polish lowlands. On the other hand, spreading of the species form the north to the south is limited only by the Alpes. I also tried to distinguish the group of species whose ranges are not influenced by these...
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Phenology of mangroves
Hradečný, Jakub ; Koubek, Tomáš (advisor) ; Sklenář, Petr (referee)
The mangroves are a globally important ecosystem with an important value for many organisms, humans included. Many of the organisms are addicted to leaf production, as a part of their diet. These foliovorous organisms are directly affected by mangrove phenology, which presents differences on the global scale. It seems possible that the phenology is influenced mainly by annual temperature oscillations and its changes mark the start and the end of phenological periods. The phenology of mangroves can be influenced by another climatic factor too, as for instance rainfall or salinity. In the latitudes of 20ř, the phenological phases show unimodal mode with the long duration of phenology periods, usually longer than one year. Closer to the equator, the phenology of the plants becomes to change into a bimodal mode, with more than one peak of phenological event per year. In the area of the equator, the phenology of the plants changes into a multimodal mode, without differences during the whole year. This ideal model can be changed by local climatic extremes changing the mangrove phenology into a different mode.
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Distribution of herbivorous fish is frozen by low temperature
VEJŘÍKOVÁ, Ivana
The number of herbivores in populations of ectothermic vertebrates decreases with increasing latitude. At higher latitudes, fish consuming plant matter are exclusively omnivorous. We assess whether omnivorous fish readily shift to herbivory or whether animal prey is typically preferred. We address temperature as the key factor causing their absence at higher latitudes and discuss the potential poleward dispersion caused by climate changes. A controlled experiment illustrates that rudd (Scardinius erythrophthalmus) readily utilize plant matter at water temperatures above 20 °C and avoid its consumption below 20 °C. Field data support these results, showing that plant matter dominates rudd diets during the summer and is absent during the spring. Utilizing cellulose requires the enzyme cellulase, which is produced by microorganisms growing at temperatures of 15-42 °C. Water temperatures at higher latitudes do not reach 15 °C year-round; at our latitude of 50°N~150 days/year. Hence, the species richness of omnivorous fish decreases dramatically above 55° latitude. Our results provide support for the hypothesis that strict herbivorous specialists have developed only in the tropics. Temperatures below 15 °C, even for a short time period, inactivate cellulase and cause diet limitations for omnivorous fish. However, we may expect increases in herbivory at higher latitudes caused by climate change.
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Geographic variability in the size of maternity colonies of cave bats
Oppelová, Tereza ; Lučan, Radek (advisor) ; Andreas, Michal (referee)
Main goal of this thesis was to compare geographical variability of sizes of colonies in the relationship with the type of roost of 6 models of originally cave bats species: Greater mouse-eared bat (Myotis myotis), Geoffroy's bat (Myotis emarginatus), Common bent-wing bat (Miniopterus schreibersii), Greater horseshoe bat (Rhinolophus ferrumequinum), Lesser horseshoe bat (Rhinolophus hipposideros) a Mediterranean horseshoe bat (Rhinolophus euryale). The selected data set was also analyzed the possible influence of the composition of land cover in roosts around the variability of the size of the colonies. Based on compilation of literature and active communication with regional bat-monitoring coordinators, entries about size of colonies from 2 603 locations in 24 countries of Europe were collected. 1 952 entries were from roosts in buildings and 651 from caves. Based on statistical analysis, conclusive influence of type of roost on size of colonies by M. schreibersii, M. myotis a R. hipposideros was discovered. While in M. schreibersii and M. myotis are human colonies in smaller buildings, in R. hipposideros by contrast, they are larger. Simultaneously, north-west gradient in geographical distribution of maternal bat- colonies in dependence on type of roost (caves vs. buildings): in southern areas...
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On the Nothernmost and Southernmost Limits of European Land Snail Spatial Ranges
Křepelová, Lucie ; Juřičková, Lucie (advisor) ; Horsák, Michal (referee)
The aim of this work was to evaluate the limits of ranges of European land snail species along the north-south gradient. To work out the document it was necessary to prepare the set of digitalized maps, that enabled to create the database of ranges of the individual land snails species. Based on obtained data I tried to identify places where the northern and southern borders of species ranges are the most frequent. The landsnails' ranges are affected not only by particular life requirements of the individual species (potential limits), but also by other conditions, especially climatic, geographical and historical (truncated limits). In this work I focused on their differentiation. Above mentioned process also enabled me to track the north- south changes in species richness of the landsnails taking into consideration the truncated and potential limits. The most important natural barriers constraining that numerous of species cannot naturally widespread from the south to the north are the Scandinavian Mountains, the Alpes and the Carpathians and suprisingly also southern borders of german and polish lowlands. On the other hand, spreading of the species form the north to the south is limited only by the Alpes. I also tried to distinguish the group of species whose ranges are not influenced by these...
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