The expansion of urban areas is one of the most significant anthropogenic impacts on the natural landscape. Due to their sensitivity to stressors in both aquatic and terrestrial habitats, dragonflies and damselflies (the Odonata) may provide insights into the effects of urbanisation on biodiversity. However, while knowledge about the impacts of urbanisation on odonates is growing, there has not been a comprehensive review of this body of literature until now. This is the first systematic literature review conducted to evaluate both the quantity and topics of research conducted on odonates in urban ecosystems. From this research, 79 peer-reviewed papers were identified, the vast majority (89.87%) of which related to studies of changing patterns of biodiversity in urban odonate communities. From the papers regarding biodiversity changes, 31 were performed in an urban-rural gradient and 21 of these reported lower diversity towards built up city cores. Twelve of the cases of biodiversity loss were directly related to the concentrations of pollutants in the water. Other studies found higher concentrations of pollutants in odonates from built-up catchments and suggested that odonates such as Aeshna juncea and Platycnemis pennipes may be candidate indicators for particular contaminants. We conclude by identifying current research needs, which include the need for more studies regarding behavioural ecology and life-history traits in response to urbanisation, and a need to investigate the mechanisms behind diversity trends beyond pollution., Giovanna Villalobos-Jiménez, Alison M. Dunn, Christopher Hassall., and Obsahuje bibliografii
The evaluation of resident fi sh communities is an important component of the ecological status assessment in aquatic habitats. Despite signifi cant water quality improvement in the Czech Republic in the last decade, several important pollution sources in the Elbe River basin remain. The aim of the study was to evaluate fish community in a chronically polluted part of the channelized lowland Elbe River and its potential indicative capability. The effluent from both industrial and municipal sewage treatment plant exhibited low pH, high conductivity and wide set of organic compounds (PAH, PCB, DDT etc.). Ecological characteristics of fi sh communities were obtained by boat electro fishing at selected sites in four inter-weir sections in July 2005 and 2006. Relatively high fish species richness (24 species) was observed in both seasons. Generalists (bleak, roach, chub) form the majority of the fish community in all four sections. There was no significant difference in fish species richness or density among study sections (river segments between weirs) even with a high level of measured organic compounds at the pollution inlet. Signifi cant differences in fish species richness and density were registered among individual sites within study sections. Sites downstream the weirs had signifi cantly higher species richness and density than the other two sites in the middle and upstream weirs. Fish community does not display any indicative remarks concerning water pollution, or in the case of mid-size river, sampling strategy was not effi cient to recognize it. Channelization and regulation of the study stretch of the Elbe River seems to be the most important determinant of fi sh community structure.
As urbanisation is set to continue, understanding the impact on wildlife becomes increasingly important if we are to be able to conserve biodiversity. As an excellent group of bioindicators, invertebrates can allow us to understand some of the forces in urban areas which impact upon biodiversity and wildlife populations. This paper discusses some of the trends in the abundance, diversity and richness of invertebrates related to urbanisation and the specific urban environmental and traffic factors which may be at play., Elizabeth L. Jones, Simon R. Leather., and Obsahuje seznam literatury
Epifytické lišejníky jakožto citlivé bioindikátory rychle reagují na změny v životním prostředí, zvláště na znečištění ovzduší. V období kyselých dešťů došlo v ČR k zásadní proměně epifytických společenstev. Existují však místa, která byla ovlivněna jen v menší míře a doposud zde přežívají vzácné druhy. Takové lokality můžeme považovat za novodobá refugia., Epiphytic lichens as sensitive bioindicators reflect changes in the environment (e.g. air pollution) very quickly. Acid rains occurring in the second half of the 20th century have considerably affected the epiphytic biota of the Czech Republic. However, there are several places, which have been less influenced and where rare lichens still survive. We consider such places to serve as recent refugia., and Jiří Malíček, Lada Syrovátková.
The gills of 63 specimens of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from three localities of the Mediterranean (Sardinian, Tyrrhenian and Levantine Seas) were examined for metazoan parasites. The parasite fauna of T. thynnus from the Sea of Sardinia included 11 species: five didymozoid trematodes, three capsalid and one hexostomid monogeneans, and one caligid and one pseudocycnid copepods. Four didymozoids were found in fish from the Levantine Sea and only one didymozoid was recorded in fish from the Tyrrhenian Sea. Dividing the hosts into four size-groups (small, medium-sized, large and extra large), the pairwise comparison of prevalence and mean abundance of the new and literary data) showed differences according to host size. The differences in the composition of the parasitic faunas and in the prevalence of parasites, observed between the small tunas from the Tyrrhenian Sea and the medium-sized tunas from the Adriatic Sea, Levantine Sea and the North-East (NE) Atlantic Ocean, indicated that these groups form discrete units. The parasite fauna of the large tunas from the Sea of Sardinia is the richest among the bluefin tuna populations of the Mediterranean and the NE Atlantic, due to the presence of species not found elsewhere in bluefin tunas, such as Caligus coryphaenae Steenstrup et Lütken, 1861, Capsala magronum (Ishii, 1936) and C. paucispinosa (Mamaev, 1968). This fact and the prevalence of some parasites of this group (lower than those of medium-sized fish from the NE Atlantic and higher than the small and medium-sized tunas from the Mediterranean) suggest that the large-sized tuna group in the western Mediterranean is formed by Mediterranean resident tunas (poorly infected), and by tunas migrating from the Atlantic Ocean (heavily infected).
Článek pojednává o poněkud nenápadné hmyzí skupině našich vod - potápnících (Coleoptera: Dytiscidae). V ČR žije přes 130 druhů potápníků. Jsou důležitou součástí společenstev jako predátoři a mohou sloužit i k bioindikaci kvality vody. Řada druhů je ohrožena rozsáhlými změnami v krajině v posledních 50 letech, např. narovnáváním řek či eutrofizací rybníků a mokřadů., The article deals with somewhat inconspicuous aquatic insects in our waters - diving beetles (Coleoptera: Dytiscidae). More than 130 species are present in the Czech Republic. They are an important part of aquatic communities as predators and may also serve as water quality biondicators. Many species have been threatened by large-scale changes in the landscape over the last 50 years, including regulation and damming of rivers and eutrophication of ponds and wetlands., and Vojtěch Kolář, David Boukal.