Iskanje po repozitoriju

A+ | A- | | SLO | ENG

Povzetek: Interstitial water that occupies the pore spaces within unconsolidated sediments is a unique habitat, inhabited by surface as well as exclusively subterranean species (stygobionts). The best studied of all interstitial habitats is the hyporheic zone, an interface between surface water and groundwater (phreatic zone) environments. The Sava River in central Slovenia (i.e., at the Ljubljana alluvial plain) readily qualifies as one of the global hotspots of interstitial biodiversity, while data from other river sections are lacking. In 2015, we sampled two gravel bars on the final Slovenian section of the river (Eastern Slovenia), and collected nine samples per site using the Bou-Rouch pumping method. At »Čatež ob Savi« and »Obrežje« sites, at least 26 invertebrate species with 14 stygobionts and 25 invertebrate species with 13 stygobionts were identified, respectively. Altogether, 33 invertebrate taxa with 16 stygobionts were recorded, which increased the previously known interstitial stygobiotic richness of the Sava River in Slovenia by eight species (to 37 species). Three species of the stygobiotic amphipod genus Niphargus were recorded in Slovenia for the first time, one of which is even a new species to science. We discuss the novel results in the context of current national conservation practices.
Ključne besede: interrstitial fauna, hyporheic, stygobionts, endemic species, Bou-Rouch pumping method, Sava River, Slovenia
Objavljeno v DiRROS: 12.03.2025; Ogledov: 153; Prenosov: 131
Celotno besedilo (459,58 KB)
Gradivo ima več datotek! Več...

Povzetek: The Dinarides in the Western Balkans host a globally exceptional subterranean biodiversity, but still areas remain with little or no data on subterranean species. In this work, we present the study of subterranean fauna in the upper Neretva River catchment (Eastern Bosnia and Herzegovina), which included the first systematic exploration of the interstitial habitats in the country. During the five-day »Neretva Science Week« in the summer of 2022, we sampled six gravel bars, six springs and one cave. We gathered 268 records (taxon-locality-date) of 116 taxa, with 35 records referring to 27 terrestrial taxa. Nine terrestrial taxa were sampled in a cave, while 19 were found in aquatic samples, mostly from springs. 27 taxa were identified as obligate subterranean (troglobiotic) species, one terrestrial beetle from the cave, and 26 aquatic species, belonging to water mites, snails, and crustaceans. Eight of the aquatic troglobionts present the potential for new species to science. Of the latter, four species were distinguished based on morphology: two species of snails from the families Hydrobiidae and Moitessieriidae, one representative of Ostracoda and one Copepoda. Individuals of the aquatic troglobiotic isopods and amphipods were analysed molecularly, and based on molecular differences, two new species within the genus Proasellus and two within the genus Niphargus were proposed. Further work on all these taxa is needed for the formal descriptions of the new species to science. Despite the short study period, we have shown that the area is rich in endemic groundwater fauna. The hydroelectric power plant constructions planned in the region threaten groundwater communities by altering subterranean habitats and their connectivity. Further studies are needed to properly highlight the great diversity of the subterranean habitats of the Neretva River catchment and its wider region, and to include this knowledge in conservation strategies.
Ključne besede: troglobiont, Proasellus, Niphargus, Kerkia, Paladilhiopsis, Typhlocypris, Bryocamptus, water mites, conversation, hyporheic
Objavljeno v DiRROS: 04.03.2025; Ogledov: 147; Prenosov: 64
Celotno besedilo (1,09 MB)
Gradivo ima več datotek! Več...

Povzetek: Dams and reservoirs are a common and globally widespread anthropogenic disturbance with documented negative effects on riverine and riparian habitats. The two most well-known impacts of river damming are longitudinal fragmentation of surface running waters and a shift from lotic habitats towards habitats with lentic characteristics that affect the benthic and pelagic communities. However, there is very little empirical evidence about the effects of damming on the aquatic fauna inhabiting interstitial habitats extending in and alongside the river-bed (i.e., hyporheic zone). In this study, we investigated the patterns in the interstitial community composition upstream, downstream and within the reservoir that was formed 80 years ago, when the river was dammed for the hydropower production. We used the rare opportunity to directly access the bottom of the reservoir drained due to dam maintenance in January 2018, to compare physical, chemical and faunistic data from the reservoir area, with those from downstream and upstream reaches of the two gravel bed rivers that are flowing into the reservoir. We sampled the interstitial invertebrate communities at seven locations, using a Bou-Rouch pump at two depths (30–60 cm and 60–90 cm within the river bed) and at three sampling points within each location. At the same sampling points we measured also physical and chemical parameters (temperature, conductivity, oxygen and pH). The interstitial water from the deepest point of the drained reservoir had substantially lower oxygen concentration, lower pH, and higher conductivity than water from the other sampling localities. This was also the site where taxa richness was lowest, and only one obligate groundwater species (i.e. stygobiont) was found. Most probably, the changes in morphology of the river channel and speed of water flow due to damming, which increased sedimentation rate and clogging of interstitial habitat, resulted in such large differences in environmental conditions and invertebrate community composition. This study provides rare empirical evidence of the effects of damming on the river interstitial habitats and fauna within the reservoir area. We recommend that environmental impact assessments conducted prior dam constructions should include also assessment of the effect of river damming on the interstitial communities. These organisms are playing important role in driving important ecosystem processes, such as organic matter degradation on one hand, and on the other hand, are composed of many rare and endangered species that need to be protected.
Ključne besede: damming, interstitial habitats, subterranean fauna, invertebrate communities, stygobionts, dam, hydropower, environmental impact
Objavljeno v DiRROS: 22.11.2024; Ogledov: 322; Prenosov: 151
Celotno besedilo (1,06 MB)
Gradivo ima več datotek! Več...