Invasive American crayfish <Emphasis Type="Italic">Pacifastacus leniusculus</Emphasis> (Decapoda: Astacidae) in the Morava River (Slovakia)

The signal crayfish, Pacifastacus leniusculus (Dana, 1852), was recorded in the Slovak-Austrian stretch of the Morava (March) River in the Záhorie region in August 2006. This is the first confirmed record of a non-indigenous crayfish species of American origin in Slovakia. Most likely, signal crayfish were intentionally released to the river by Austrian fishermen, or invaded from adjacent water bodies in Austria. As this species has a substantial invasive capability and is a potential vector of the crayfish plague pathogen, it represents a threat to the native crayfish species and its spread should be monitored. Its invasion upstream to the territory of the Czech Republic is not unlikely in near future.     

Changes in lepidopteran assemblages in Temnosmrečinská dolina valley (the High Tatra Mts,Slovakia) over the last 55 years

Lepidopteran assemblages in Temnosmrečinská dolina valley (High Tatra Mts, Western Carpathians, Slovakia) were investigated. Recent data about the occurrence of lepidopteran species are compared with those which were obtained 55 years ago. Lepidoptera were monitored at seven sites comprising the subalpine to alpine zone of the valley. Fifteen of the originally recorded species were not found, however, the occurrence of six new species was recorded. In total, 61 summer lepidopteran species are known from the Temnosmrečinská dolina valley. The comparison of the recent lepidopteran assemblages shows a decline in species richness, abundance and frequency at individual monitoring sites. It seems that the changes are caused by plant community succession in the valley — overgrowth of dwarf pine, transformation of meadow communities to Calamagrostigetum and overgrowth of peat-bogs, resulting in loss of food resources for adult Lepidoptera.     

Past and current status of sturgeons in the upper and middle Danube River

Of the six species of sturgeons native to the Danube basin, five occurred in the upper and middle Danube. Among anadromous sturgeons were the large winter races of beluga, Huso huso, Russian sturgeon, Acipenser gueldenstaedtii, and stellate sturgeon, A. stellatus, which ascended the middle, and sometimes also the upper Danube, to spawn. Due to overfishing, followed by severe habitat alteration including damming and pollution, these anadromous sturgeons are critically endangered or extirpated from the upper and middle Danube. Acipenser gueldenstaedtii and A. nudiventris are represented only as resident non-migratory races with very small populations. The most abundant and widely distributed species is the sterlet, A. ruthenus, although it is presently limited to the middle Danube. Its population increased in some sections of the middle Danube during the past 15 years, presumably because of improving water quality, but this species remains at risk because of continuing habitat degradation.     

Climate sensitivity of high- and low-elevation Larix decidua MXD chronologies from the Tatra Mountains

Maximum latewood density (MXD) measurements from high-elevation/-latitude sites are an important proxy for summer temperature reconstructions. Here, we present 201 MXD series from living larch (Larix decidua Mill.) trees that were growing at around 850 and 1450 m a.s.l. in the Slovakian Tatra Mountains, together with 56 MXD series from historical timbers of the same species and region. We explore the climate signal at the high- and low-elevation sites and assess the effects of varying temperature and precipitation regimes on MXD formation. Ranging from spring temperature to summer precipitation, the elevation-specific climate sensitivity suggests that the MXD measurements from living and relict sources should not be merged for paleoclimatic studies. This finding emphasizes the challenge of attributing a predominant climate factor that controls wood formation across a wide range of historical constructions. A better understanding of the ‘true’ climate signal requires more samples during the period of overlap between the living and historical trees.     

Hieracium vierhapperi (Asteraceae) a new species to the Carpathians, with some remarks on its origin

Hieracium vierhapperi (Zahn) Szeląg, known so far only from the Alps, was discovered in the Nízke Tatry Mts in Slovakia, as a new species to the Carpathians. Diagnostic characters, illustration and distribution as well as ecology of H. vierhapperi in the Nízke Tatry Mts are given. A key to distinguish H. vierhapperi from the morphologically related species is added. The Carpathian plants are tetraploid (2n = 36) and reproduce apomictically. The origin of H. sect. Cernua R. Uechtr in the Western Carpathians is briefly discussed.     

Life History and Secondary Production of Mayflies (Ephemeroptera) Indicate Disturbance in Two Small Carpathian Streams

The life histories and the secondary production of 9 mayflies (Ephemeroptera) species were studied at two sites in a submountain stream (West Carpathians, Slovakia). The disturbed site has a deforested and converted to meadows and pastures catchment and the undisturbed one is a well‐preserved submountain stream with 60% of the catchment covered by spruce forests. Differences in the forest cover and in the thermal regime of both streams were reflected in the structural as well as the functional measures. At the undisturbed site, the total secondary production of mayfly community was more than two times higher (3568 mg DW m^–2 y^–1) than at the disturbed site (1446 mg DW m^–2 y^–1). Species could be divided according to their affinity to particular disturbance level. Ecdyonurus picteti, Rhithrogena carpatoalpina, Habrophlebia lauta and Habroleptoides confusa appeared to prefer undisturbed conditions. On the contrary, Ecdyonurus aurantiacus and Habrophlebia fusca occurred only at the disturbed site. The dominant species Baetis rhodani and Electrogena samalorum did not show any clear preference regarding the catchment disturbance. However, nymphs of Electrogena samalorum seem to be more successful at the disturbed site, where they reached bigger body sizes (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Eretes diving beetles (Coleoptera: Dytiscidae) in Central Europe – witnesses of climate change?

Records of the predaceous diving beetles of the genus Eretes Laporte, 1833 (Coleoptera: Dytiscidae) in Central Europe are summarised. While old records from the beginning of the twentieth century from the Czech Republic, Hungary, and Romania belong to Eretes griseus (Fabricius, 1781), a species which has not been recaptured in Central Europe for nearly the last hundred years, recently collected specimens from Hungary and Slovakia belong to E. sticticus (Linnaeus, 1767) and represent its first records in these countries as well as in Central Europe. The first specimens were collected at light during hot summer nights and may document a recent spreading of the species from the Mediterranean. In addition, the occurrence of E. sticticus is formally confirmed in Bulgaria, Croatia, Greece, Israel, Libya, South European Territory of Russia, and Tunisia.     

Influence of seasonal variation on bioassessment of streams using macroinvertebrates

The EU Water Framework Directive requires assessment of the ecological quality of running waters using macroinvertebrates. One of the problems of obtaining representative samples of organisms from streams is the choice of sampling date, as the scores obtained from macroinvertebrate indices vary naturally between seasons, confounding the detection of anthropogenic environmental change. We investigated this problem in a 4th order calcareous stream in the western Carpathian Mountains of central Europe, the Stupavsky potok brook. We divided our 100 m study site into two stretches and took two replicate samples every other month alternately from each stretch for a period of 1 year, sampling in the months of February, April, June, August, October and December. Multivariate analysis of the macroinvertebrate communities (PCA) clearly separated the samples into three groups: (1) April samples (2) June and August samples (3) October, December and February samples. Metric scores were classified into two groups those that were stable with respect to sampling month, and those that varied. Of the metrics whose values increase with amount of allochthonous organic material (ALPHA_MESO, hyporhithral, littoral, PASF, GSI new, DSI, CSI), the highest scores occurred in February, April, October and December, while for metrics whose values decrease with content of organic material (DSII, DIS, GFI D05, PORI, RETI, hypocrenal, metarhithral, RP, AKA, LITHAL, SHRED, HAI) the highest values occurred in February, April, June and December. We conclude that sampling twice a year, in early spring and late autumn, is appropriate for this type of metarhithral mountain stream. Sampling in summer is less reliable due to strong seasonal influences on many of the metrics examined while sampling in winter is inappropriate for logistical reasons. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

Perapion connexum (Schilsky, 1902) (Coleoptera, Apionidae) in Central Europe, a case of plant expansion chase

Perapion connexum (Schilsky) is recorded for the first time from Hungary and Kyrgyzstan, and new distribution data from Ukraine and Russia are provided. Preliminary placements of this weevil in faunal checklists for Poland and Slovakia are here documented with detailed data. Its occurrence in Austria based on older evidence, is discussed. The neophytic and invasive in Central Europe sorrel Rumex confertus Willd. is confirmed to be its unique host plant in Poland. Morphology of the newcoming weevil is described and illustrated, and the key to all Central European species of Perapion is presented.     

Testing a relict distributional pattern of fen plant and terrestrial snail species at the Holocene scale: a null model approach

Aim The term relict refers to a formerly widespread species currently occurring in refugia that provide a persistent combination of specific ecological conditions. In peatlands, direct palaeoecological evidence of relict status exists for some plant species and, in the case of calcareous sediments, for some snail species. We tested whether some species are significantly linked to old calcareous fens at the millennial scale independent of the effect of recent fen area. We focused on three organism groups – vascular plants, bryophytes and land snails – that differ in the degree of preservation of their remains in calcareous fen sediments and in their dispersal ability. Location Western Carpathians (Slovakia and the Czech Republic). Methods The sample sites comprised 47 well‐preserved calcareous fens, from which we compiled complete recent species lists, measured the area and analysed radiocarbon‐dated samples from the deepest sediment and from the beginning of complete deforestation, as indicated by plant and snail fossils. Using the species co‐occurrences in large data sets, we identified calcareous fen specialists and compared their recent distribution patterns against a null model that controlled for the effect of fen area. Results Two land snail species, eleven vascular plant species and no bryophyte species have statistically significant affinities with old fens, independent of the effect of recent fen area. For one bryophyte and one snail, the effects of age and area are not distinguishable. Main conclusions The results for land snails, being abundantly preserved and easily determinable in calcareous fen deposits, are in full accordance with the direct macrofossil evidence. This suggests that our approach indirectly revealed a relict distribution of the species. Identification of species that are significantly linked to ancient localities at the millennial scale has great potential in palaeoecology for the detection of stands with old sediments, and in nature conservation as a tool for the identification of long‐term‐persisting rare species that infrequently colonize young sites and thus deserve priority in the protection of their habitats. From a theoretical perspective, limited dispersal from old to new localities of the same habitat can contribute to spatial effects in biotic assemblages, even at relatively fine scales.