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Vulnerable benthic water bug species \kur{Aphelocheirus aestivalis }(Fabricius, 1794) (Heteroptera: Aphelocheiridae): distribution and habitat preference in the Czech-Austrian border area of the Lužnice river basin
BAUER, Martin
The occurence, ditribution, habitat preference of benthic water bug Aphelocheirus aestivalis, and structure of macroinvertebrate benthic communities were studied in the upper Lužnice River basin. A. aestivalis is distributed only in a lower part of the upper Lužnice river basin. It inhabites stony biotopes of Dračice river (= Reissbach in the Austrian side), Lužnice river downstream from Suchdol nad Lužnicí, Old part of Lužnice river, Nová řeka river, and Nežárka river. This species occurs only in the rocky and sandy bottom where current speds and dissolved oxygen are both high in the investigated area. Prefered microhabitats are represented by sand and coarse gravel, that overline the larger boulders, rocks, dead woods or rootlets of trees growing in banks and sandy places with submerged plants. Though the Lužnice river has numerous sites of character of prefered habitats and microhabitats also upstream from Suchdol nad Lužnicí, any specimens of A. aestivalis were never found upstream from this small city and in the Koštěnický potok brook (mouth of this right side tributary into Lužnice river is located dovnstream from Suchdol nad Lužnicí). The macroinvertebrate benthic communities in the sites with occurence of A. aestivalis include larvae of following species of water insects: Cloeön dipterum, Baetis vernus, Ephemera danica, Ephemerella ignita, Heptagenia sulphurea (Ephemeroptera); Isoperla cf. rivulorum, Leuctra cf. albida (Plecoptera); Hydropsyche pellucida or incognita, H. angustipennis, Limnephilus sp., Molanna angustata, Polycentropus flavomaculatus, Potamophylax sp. (Trichoptera). Dominant and most abundant insects were Hydropsyche larvae. It is possible to suppose that the larvae of Baetis, Ephemerella (Ephemeroptera) and Hydropsyche (Trichoptera) larvae are prefered prey of A. aestivalis in the investigated area. The Lužnice river is characteristic by often floods including the destructive ones. Chemical parameters of water change espec
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Odonata in the urban landscape
Fiala, Bohumil ; Černý, Martin (advisor) ; Harabiš, Filip (referee)
Urbanization is currently one of the main causes of landscape destruction, endangerment of species and homogenization of natural communities. Dragonflies are an important part of freshwater ecosystems. Due to their amphibious life cycle, they are influenced by environmental factors both in a water and on a dry land. Despite the negative impact of urbanization on the environment, the urban landscape has the potential to host a great diversity of organisms, including dragonflies and damselflies. The best way to support local diversity of Odonata is by appropriate management of freshwater habitats, including promoting diversity of aquatic, litoral and riparian vegetation, preserving the original bottom and banks of both lotic and lentic waters and improving water quality in cities. The connectivity of individual localities in the landscape and the reduction of ecological traps are also important ways to ensure the stability of urban populations. Small artificial water reservoirs and well-preserved secondary habitats have the highest conservation potential in most cities. Dragonflies can also play the role of umbrella species for the protection of freshwater communities (not only) in urban areas.
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Potravní ekologie koní v kontextu ochranářského managementu krajiny
HÁJKOVÁ, Pavlína
This thesis provides a review of knowledge available on wild and feral horse feeding ecology, habitat preferences, competition overlap with other herbivores and their impact on vegetation. In summary, horses appear valuable for management of grasslands, but less suitable for regulation of shrubs and trees, especially when they are compared to cattle and cervids, which are more able to eliminate woody plants. Together with a tabular overview of literature on feeding ecology and plant taxa eaten by horses in the Holarctic realm, an optimalized protocol is provided to facilitate proper field collection of data about the feeding ecology and behavioral repertoire in large ungulates.
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Distribution and habitat preference of the Ortolan Bunting in the Czech Republic
Zeman, Vít ; Lučan, Radek (advisor) ; Šťastný, Karel (referee)
The Ortolan Bunting (Emberiza hortulana) is a farmland bird species, whose population size has declined very sharply in recent decades, especia ll y in Western and Central European countries. The aim of our study in 2015 was to record where the last populations of this critically endangered species in the Czech Republic are located and also what habitat the species associated with. We examined nine areas (925 km2 in total). Two main areas of occurrence (surface mines in northern Bohemia and farmland landscape of Silesia) and two small isolated populations in central Bohemia were registered for this species. In contrast, observations in some traditional areas of its occurence (České středohoří in northern Bohemia, Hovorany-Čejkovice region in southe r n Moravia and Javoricko region in Silesia) were negative. Altogether, we counted 75-79 singing males. Our estimation of the size of the Czech population in 2015 is 75-100 singing males, which indicates further population decline compared to the last mapping in 2001-2003. Furthermore, habitat associat io ns were investigated at two spatial scales and we made habitat compar is o n between farmland and post-mining landscape. Our research highlights a high degree of flexibility in habitat selection of Ortolan Bunting and also positive association with high...
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