Vplyv výškového gradientu na spoločenstvá bĺch drobných cicavcov

The monograph deals with the analysis of the impact of changes in altitude on the flea assemblages of small mammals along an elevational gradient in Slovakia. This type of research is urgently needed, as the composition of communities is rapidly changing because of global climate change. Comparison of different gradients in a variety of biogeographical regions also helps to understand biodiversity mechanisms. The thesis seeks to determine whether altitude influences this taxonomic group of organisms in the conditions found in Slovakia. Should the effect be confirmed, one objective would then be to determine the pattern of flea diversity changes. Data from 1976-93, 1998 and 2001 were analysed by us, consisting of more than 65,000 fleas from 31 species. The host sample consisted of nine species of small mammals: Apodemus agrarius, A. flavicollis, A. sylvaticus, Clethrionomys glareolus, M. agrestis, M. arvalis, M. subterraneus, Sorex araneus and S. minutus. The altitudinal gradient ranging 1,600 meters from lowland to subalpine zones was analyzed.
Both the altitudinal gradient and factors that change with rising elevation have a significant impact on the attributes of flea communities that small burrowing mammals host. The main lesson that has been learned is to generally formulate the change in these attributes under conditions in Slovakia, which for this group of organisms is a unimodal pattern of diversity with a mid-elevation peak. It is considered to be the most frequently occurring diversity change trend throughout the world, contributing toward an increase in knowledge about global biodiversity samples. Comparing the most manifold gradients in various climates, bio-geographies and among mountain ranges of varying sizes and conditions helps in obtaining an understanding of biodiversity mechanisms, especially at a global level, and to analyze potential impacts from climate change. This type of research is necessary because organism communities are going to be affected by climate change and their responses to these changing conditions are themselves rapidly changing. Global climate change generally caused by rising air temperature and declining precipitation may be influencing the sampled diversity of organisms along environmental gradients. There is a greater probability that even parasitic taxa will not avoid the changes, altering the spatial distribution of the pathogens they transmit.

A major impact of changing altitude and related factors on flea communities assembling on small burrowing mammals in Slovakia has been confirmed by us. To a significant degree, altitude affects the parasite-host-environment relationship and this has been reflected in the host index preference of specific fleas, such as A. arvicolae, A. rossica, as well as opportunistic flea species like H. talpae). An analysis of diversity and species richness among a selected nine small burrowing mammalian species found altitude to have a significant impact. In Slovakia, these community attributes have been changing, as noticed in a unimodal pattern whose curves peak at mid-elevations of approximately 700-900 meters.
Understanding biodiversity patterns among organisms is critical and, of course, the same goes for parasitic organisms. Parasites are likewise part of communities, play a major role in regulating the population of their hosts and are considered an important group of organisms in the study of diversity. Even though small burrowing animals host flea communities, the fleas rarely infest humans because they do not share the same habitats and the pathogens the fleas spread are not transmissible to humans. Nevertheless, we consider it essential to monitor it. Since we are working with historical data not primarily designed for adaption to an analysis of elevational gradients, it is recommended, as part of further research into the issue, to add to the collection of data factors directly related to changes in altitude, such as temperature, relative humidity, precipitation and vegetation cover, in order to obtain a more detailed analysis of how individual factors influence both communities of this parasitic group and their hosts.