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The capability of a non-native species to withstand adverse weather is indicative of its establishment in a novel area. An unusually cold winter of 2016/2017 that occurred in the West Carpathians of Slovakia and other regions within Europe provided an opportunity to indirectly assess survival of the invasive ambrosia beetle Xylosandrus germanus (Coleoptera: Curculionidae, Scolytinae). We compared trap captures of this species in the year preceding and succeeding the respective cold winter. Ethanol-baited traps were deployed in 24 oak dominated forest stands within the southern and central area from April to August 2016, and again from April to August 2017 to encompass the seasonal flight activity of X. germanus and to get acquainted with temporal changes in the abundance of this species in these two distant areas. Dispersing X. germanus were recorded in all surveyed stands before and after the aforementioned cold winter. Their total seasonal trap captures were lower in the southern area following low winter temperatures, but remained similar in the central area. Our results suggest that X. germanus can withstand adverse winter weather in oak dominated forests of the West Carpathians within altitudes of 171 and 450 m asl. It is likely that minimum winter temperatures will not reduce the establishment or further spread of this successful invader in forests in Central Europe.

Understanding of habitat favourability has wide relevance to the invasion biology of alien species. We studied the seasonal dynamics of the alien ladybird Harmonia axyridis (Coleoptera: Coccinellidae) in monoculture Scots pine forest stands in south-west Slovakia, Central Europe, from April 2013 to March 2015. Adult H. axyridis were collected monthly across seven randomly selected pine stands of different ages and canopy closure, from the lower branches of pine trees, and larvae were recorded qualitatively. Adults were recorded all year round, most abundantly in November and least abundantly in February. The relationship between the abundance of H. axyridis and selected forest stand characteristics was modelled using the negative binomial Generalized Additive Model with penalized spline component in month (seasonality) effect, year, canopy closure and age effects and the random effect of forest stand (sample area effect). The abundance of H. axyridis was significantly influenced by the age of stand and seasonality (with month granularity) for both closed and open canopy stands, whereas the effects of canopy closure and sample area were not significant. The bimodal pattern of seasonal dynamics of H. axyridis on Scots pine was common for closed and open canopy stands, with two peaks reflecting the cyclic movement of the species from and to overwintering sites. Harmonia axyridis utilized certain pine stands preferably for foraging during the growing season and certain stands for refuge during winter. The ladybirds were found in highest numbers in the 15 year old closed canopy stand (overwintering site). The occurrence of both adults and larvae in most stands indicated a suitability of Scots pine forest for ladybird breeding. The model of year-round dynamics of H. axyridis has been presented for the first time within the invaded range of the ladybird in Europe.

The article presents a recent update of a comprehensive dataset of long‐term series of precipitation data from instrumental observations in the Greater Alpine Region (GAR), that is, the region of Europe including the Alpine mountain range and their nearer surroundings (4°–19° E in longitude and 43°–49° N in latitude). A comparison to different national homogenized datasets is also presented. Results show that in the national homogenized datasets more breaks have been detected due to higher station density. They also demonstrate the necessity of constant exchange with data providers. The resulting trends in all datasets are mainly weak and only a minority of them is statistically significant. In most cases the similarity of statistical index numbers are promising, with, for example, small RMSE between the presented new HISTALP homogenization and the time series of the national homogenized datasets. Nevertheless, for some stations higher differences occur and break signals are not what would be expected due to possible causes in the station history. The differences between the national and the HISTALP new homogenization—due to, for example, different methods used, different points in time when the homogenization took place, different options of data handling (combination of station data, gap filling routines, ...) and different reference stations—illustrate the inherent uncertainty unavoidably associated to homogenization and point out the need of careful communication and use of the data. On the other hand, the results highlight the advantage of consistently homogenized datasets, versus the risks associated with mixing results from different homogenizations. [ABSTRACT FROM AUTHOR]

The presented study shows using of bivariate and multivariate statistical analyses in mountain area of the Krivánska Fatra Mountains affected by debris flows. Three generations of data were studied in order to assess the debris flows in the area, from these two main periods of debris flows were taken into the analysis: the debris flows from 1950s to 1970s and catastrophic debris flows from July 2014. Various input data were used in the statistical analyses: elevation, slope angle, plan curvature, topographic wetness index, flow accumulation, lithology, and land cover. Two main evaluations were made: first using the older debris flow data and second using debris flow data from the both periods. Receiver operating characteristic analysis was performed in order to assess the reliability of the models with the area under curve more than 95 % for both evaluations and more than 85 % for the first evaluation checked by both periods of debris flows in case of multivariate analysis, respectively almost 83 % and 80 % in case of bivariate analysis. The comparison with existing avalanche tracks was performed as well and shows satisfactory results. The tracks of debris flows from July 2014 show the extraordinariness of the event in comparison with older debris flows. Experimental assessment of natural hazard was performed using the map of difference between the two susceptibility maps in order to find out the areas of possible high magnitude low frequency events. [ABSTRACT FROM AUTHOR]