Only a few studies to-date have dealt with the habitat preferences of the fauna of springs. The main objective of our study was to fill this gap. The research was carried out in springs situated in the Kraków-Częstochowa Upland, Poland. The benthic fauna was collected from fine and coarse substrata using a typical hydrobiological approach. Forty-nine families or subfamilies and four higher taxa (Hydrozoa, Turbellaria, Nematoda, Hydracarina) were found in the springs studied. Invertebrates collected in springs were successfully classified into groups and, using the Analysis of Discriminant Function, were found to diverge in terms of substratum type. This prediction was 96% accurate for samples collected from fine sediments and 91% for samples collected from coarse sediments; the differences were higher in springs located in the southern part of the study area. Substratum type was found to be the main discriminatory factor with regard to the fauna density while faunal composition was related to the geographical position of springs. Our results emphasise that, even in very small habitats such as springs, all major substratum types should be considered for sampling.

Water chemistry and macroinvertebrates of four high mountain lakes (alt. 1657-1784 m) were investigated. The lakes are ultraoligotrophic with naturally slightly acidic water. In three lakes these water level changed substantially during the year while in one it remained constant. Moreover, trophic status was higher in one than in the other three. Oligochaeta and Chironomidae dominated the invertebrate fauna of all lakes. Benthic faunal composition depended mainly on ecological factors such as substrate, trophic status, and hydroperiod. It appears that anthropogenic acidification has so far not affected faunal composition. Les communautés d'invertébrés dans des lacs permanents et temporaires de haute montagne (Hauts Tatras)Mots clés : lac de haute montagne, faune benthique, chimie de l'eau, acidification, assèchement.Les paramètres chimiques de l'eau et la faune benthique de quatre lacs des Hauts Tatras (1657-1784 m) ont été étudiés. Les lacs sont ultraoligotrophes avec des eaux naturellement un peu acides. Dans trois lacs les changements de niveau de l'eau sont variables, dans un autre le niveau reste constant. De plus, l'état trophique d'un lac est plus élevé. Les espèces d'oligochètes et de Chironomidae sont les plus nombreuses parmi les invertébrés recensés dans tous les lacs étudiés. La composition de la faunebenthique dépend principalement des facteurs écologiques comme : qualité du substrat, trophie de l'eau et durée des périodes d'assèchement. Il apparaît que l'acidification causée par l'activité humaine n'affecte pas le peuplement benthique jusquà présent.

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Spatial patterns in macroinvertebrate communities and some abiotic factors were examined in three rheocrene springs and their springbrooks (Kraków-Częstochowa Upland, southern Poland). The mean discharge of particular springs ranged from 5 to 11 L s −1 , and its annual fluctuations were small. Water temperature was very stable at all sampling sites. In the eucrenon the number of benthic taxa was the smallest (9-14 determined to the family level), but the densities were the highest (approx. 14000 ind. m −2 ). The biggest changes in macroinvertebrate composition were observed in the modified hypocrenon, which is an artificial pond. The lowest number of taxa were found in a natural, short springbrook with a nondiversified bottom substrate. The density of crenophilic taxa (Drusus trifidus, Dugesia gonocephala, Elmidae) diminished along the springbrooks, while the opposite trend was observed for ubiquitous taxa (some Oligochaeta, Asellus aquaticus and Chironomidae). Even in a very short natural springbrook (30 m), Drusus trifidus, the only species of Trichoptera found in the springs discussed here, goes through the entire development cycle. The strongest influence of a big river was observed at the outflow of one of the natural springbrooks, where the highest number of riverine oligochaete species were found. The benthic fauna of the springs studied here differed from that found in other springs in this area -the absence of the typical crenophilic species Bithynella austriaca (Gastropoda) and the presence of Gianus aquedulcis (Oligochaeta) may indicate the autonomy of the spring fauna in the Mstów area, possibly resulting from the postglacial geomorphological formation of this region or differences in habitat conditions.

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