This study presents new insights into ecological traits of water beetles in lotic karst habitats of the Eastern Mediterranean. The aims of the study were to investigate population aspects and ...ecological traits of water beetles. Data were collected monthly during one year from a large perennial river showing current anthropogenic disturbance. Altogether 11 families, 23 genera and 31 species were identified. Elmidae were the most diverse and abundant family, and the genus Elmis predominated at all sampling sites. The distribution of water beetles along the river was influenced primarily by river bed morphology and beetle substrate preference. Water beetles were more abundant in bryophytes but more diverse in angiosperms. Ecological traits of water beetles along the watercourse were defined primarily by alkalinity and current velocity. Larval stages correlated with water depth and current velocity, while the adult stage correlated only with water depth. Our results support the potential of water beetles as indicators of water quality. This report provides the most detailed investigation so far of water beetles in the Eastern Mediterranean region, providing a basis for further detailed studies of water beetles and their ecology in freshwater habitats in southeastern Europe.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Poljes are flat closed karst depressions prone to regular flooding. The floods can be several meters high, last for months and damage significantly human infrastructures. To predict the maximum level ...reached, the polje water balance needs to be implemented. This technique encounters the difficulty that important part of the inflow and outflow flowing through many poljes is ungauged, as it is challenging to measure accurately the numerous springs and ponors activating temporarily with the rise of water level. This work aims to see whether this problem can be handled and the polje water balance reconstituted. To do so, a typical Dinaric polje is equipped with several water level stations installed over its surface and in the nearby water active caves. Combining a 1*1m digital elevation model of the polje surface with water levels and inflow records of the main two springs allowed assessing the variation of flooded volume and reconstructing the water balance. The highest total inflow values reached during the observed period were of about 140-150 m3/s, with up to a third of it being ungauged. In addition, the effect of a large estavelles group on the polje inflow and outflow could be identified, and helped to characterize the outflow, with values comprised between 65 and 75 m3/s. Finally, intense rainfall over the polje flooded surface showed to be a temporary important source of inflow. The values found by the water balance analysis have been used as input and calibration data in a numerical model reproducing the flood dynamics in the polje and its surrounding aquifer. Results validated both polje water balance and conceptual hydrogeological model. They justify the significance of combining water level measurements with a digital elevation model to monitor the floods. The method can be applied to other poljes flooding in a complex way of superposed input and output signals. Finally, the places to be equipped in priority if the polje has no measurement network or if available funding is limited are discussed.
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IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UL, UM, UPUK
Extreme heterogeneity of karst systems makes them very challenging to study. Various processes within the system affect its global response, usually measured at karst springs. Research conducted in ...caves provides a unique opportunity for in situ analysis of separate processes in karst underground. The aim of the present study was to research the water and air dynamics within a deep karst system. Air and water basic physical parameters across the Lukina jama–Trojama cave system (−1,431 m) were continuously monitored during a 1‐year period. Recorded hydrograph of the siphon lake at the bottom of the cave was used to interpret the characteristics of an unexplored phreatic/epiphreatic conduit network. Water origin in the siphon was determined based on temperature and electrical conductivity. Air temperature and humidity monitoring revealed a strong inflow of air of sub‐zero temperature into the upper portion of the cave during winter. Cave passage morphology was interpreted as the main determinant of air dynamics, which caused ice to accumulate extensively in the upper portions of the cave and caused the temperature on the top of the homothermic zone to be significantly below the mean outside temperature. Air dynamics also lowered the temperature of water flowing through the cave vadose zone and feeding the phreatic zone of the massif. The pronounced temperature difference between the phreatic zone and the top of the homothermic zone probably contributed to the thermal gradient observed in the cave, which is steeper than in ice‐free caves in the area. Our results enabled the development of a conceptual model that describes coupling between air and water dynamics in the cave system and its surroundings.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This study presents the first comprehensive investigation of population aspects and ecological traits of water beetles in oligotrophic hydrosystems with tufa formation in southeastern Europe. Diverse ...lotic habitats (springs, rivers and tufa barriers) were investigated monthly for one year in Plitvice Lakes National Park in Croatia. Elmidae were the most diverse and abundant family, followed by Scirtidae and Hydraenidae. The ecological traits of water beetles were primarily defined by nutrients and water depth. Elmis bosnica Zaitzev, 1908, about which little has been published, was found to be bryophilous and to prefer low water temperatures. Biogeographical analysis revealed the dominance of typical southeastern and Mediterranean species. Species population dynamics could be attributed to differences in flow permanence, current velocity and canopy coverage. Both current velocity and water depth significantly influenced the occurrence of larval stages, while abundance of adults correlated with water depth. Our results highlight tufa barriers as preferred habitats for species of the genus Riolus and the family Scirtidae. The results of this study, many of which are the first to be reported for water beetles, provide a basis for further investigations of these animals and their ecology in oligotrophic hydrosystems with tufa. In particular, our study demonstrates the potential of Elmidae as water quality indicators, which should be considered in future conservation and protection management efforts.
This study presents the first comprehensive investigation of water beetles in oligotrophic hydrosystems with tufa formation in southeastern Europe. Biological and ecological traits of so far poorly studied species are revealed.The results provide a basis for future investigations, and demonstrate the potential of Elmidae as water quality indicators in this region.
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Glaciokarst depressions are major glacigenic depocenters in the Dinaric mountain karst areas and often store important information about the timing and nature of glacial processes and paraglacial ...sediment reworking. This study focuses on Praprotna draga, which is one of the largest glaciokarst depressions in the Snežnik Mountain (Dinaric karst), with an area of ~3.4 km2 and a maximum depth of 140 m. The western slopes of the depression are characterized by undulated moraine morphology and alluvial fans are filling its entire floor. We present the results on the thickness, origin and age of the sediment infill using a complementary geomorphological, sedimentological, geophysical and dating approach. Distribution of moraines point to two glacial advances that were associated with two main alluvial fan aggradation phases recognized using the electrical resistivity tomography measurements. The youngest alluvial deposits were sampled for cosmogenic 36Cl analysis using amalgamated carbonate pebbles. The depth profile of 36Cl concentrations suggests an age of 12.3 ± 1.7 ka when assuming a likely denudation rate of 20 mm ka−1. Since the existence of the Younger Dryas glaciers in the study area is climatically difficult to explain, we tentatively propose that the youngest alluvial deposition in Praprotna draga took place after the glacier retreat during the paraglacial period. Our findings suggest that the time window of paraglacial adjustment in the Snežnik Mountain was brief and likely conditioned by quick recolonization with vegetation and inefficient surface runoff on deglaciated karst terrain.
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•The topmost ~2 m of alluvial deposits (AD2) was dated to 12.3 ± 1.7 ka.•Dated alluvial deposits are most likely of paraglacial origin.•Time window of paraglacial response to the last deglaciation in Snežnik was short.•Brief paraglacial response a result of karst drainage and quick vegetation change
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Tragovi vidljivosti koji reprezentiraju potpovršinski kontekst, kao što su tragovi u tlu (soil marks) i usjevima (crop marks), uobičajena su pojava kojom se detektiraju arheološki lokaliteti ...primjenom metode daljinskih istraživanja – zračne arheologije kroz medij kose zračne fotografije. Različite rasprave i općenito primjena metode zračne arheologije, većinom je ograničena na područja kontinentalne klime koja sadrže obilje kultivirane zemlje i tla. Arheološki lokaliteti u krškom su krajoliku primjenom metoda daljinskih istraživanja vidljivi većinom kao površinske strukture, a ne kao potpovršinski arheološki kontekst koji je reprezentiran ili posredovan tragovima u usjevima ili u tlu. U ovom radu se predstavljaju rezultati zračnog snimanja koje je obuhvatilo planinu Velebit i dio sjevernodalmatinske zaravani i obrovačke zaravni u Hrvatskoj. U tu svrhu provedena je analiza snimljenih kosih zračnih fotografija u svrhu sistematizacije indikatora vidljivosti arheoloških lokaliteta u krajoliku dinarskog krša. Indikatori vidljivosti koji omogućuju otkrivanje arheoloških lokaliteta su međuovisni o krškom reljefu, submediteranskoj klimi i vegetaciji šikara. Utvrđeno je da su arheološki lokaliteti primjenom metode zračne arheologije vidljivi kroz indikatore kao što su sjena, tekstura, boja i vegetacija. Definirani indikatori u krškom kulturnom krajoliku kojima su detektirani arheološki lokaliteti rijetko se pojavljuju samostalno. Arheološki lokaliteti su većinom vidljivi kroz kombinacije više pojedinačnih indikatora.
The Biospeleological Station (BS) in Postojna Cave, with a volume of 36,000 m3, has served as an underground biological laboratory since 1931, receiving 100,000 visitors annually. Historical cave ...micro-climate monitoring was performed in 1933 and 1963, and continuous monitoring of cave air temperature and carbon dioxide concentration at hourly intervals started in 2015. Micro-climatic data collected between 2015 and 2024 has helped us to understand the relationship between natural underground environment and anthropogenic impact, thereby aiding expert recommendations to cave managers for the mitigation of anthropogenic micro-climatic effects. Results strongly support the policy that, during summer, when outdoor temperatures are higher than in the cave, solid metal doors connecting the BS with the rest of the cave (Stara Jama) should be kept open. Such a simple mitigation act helps to decrease anthropogenically increased air temperature and carbon dioxide concentrations, thereby maintaining suitable micro-climatic conditions for the exhibition of cave animals. Closure during the COVID-19 pandemic (2020–2021) resulted in the lowest temperatures recorded. BS visitation increases air temperature by 1 °C, highlighting the need for management strategies to maintain suitable conditions for cave fauna exhibition.
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Clastic sediments deposited at the bottom of the vertical, nearly 1000 m deep Njemica Cave (Biokovo Mountain, Croatia) were analysed. Owing to the vertical morphology of the cave, the occurrences of ...clastic sediments are sparse. Small, up to decimetre-thick, undisturbed sediment accumulations situated near the siphon lake revealed interesting palaeontological and mineralogical data. These data are used as a useful proxy for discussing depositional processes, the provenance of the sediments and paleo-habitats of the subterranean fauna.
The sub-recent assemblages of ostracods were discovered within the sediment, and they were shown to be correlative to the known endemic species in the wider Dinaric Karst area (Pseudocypridopsis sywulai and Phreatocandona cf. motasi). The well-preserved sediment archive indicates the allogenic origin of the sediment and defines it as an allochthonous infiltrate of the Quaternary. The detritus originates from Pleistocene–Holocene deposits in the surrounding area, whose composition was influenced by volcanic activity in the wide Adriatic region. Sedimentation occurred in a calm aquatic environment by settling from suspension. Therefore the sediments are defined as slackwater deposits.
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The purpose of this study was to identify the influence of karst landscape on the sustainable development of the Bela krajina region, southeast Slovenia. In order to better understand the influence ...of karst landscape on sustainable development we used three approaches: (1) the Karst Disturbance Index, (2) a quantitative analysis by using sustainable development indicators and (3) a qualitative analysis using structured interviews. The Karst Disturbance Index classified the degree of disturbance in Bela krajina as low. According to sustainable development indicators we found differences in the structure related to economy, population and environment within the region. And, according to the qualitative analysis, the negative impacts of the karst landscape on sustainable development are mainly associated with hampered agriculture and the positive with tourism; thus, karst landscape cannot only be seen as a limiting factor, since it also has development potential. Regional development in karst areas should therefore be adapted to their specificities and take into account their vulnerability.
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