Acta Carsologica <p><em>Acta Carsologica</em> publishes orginial research papers and reviews, letters, essays and reports covering topics related to specific of karst areas. These comprise, but are not limited to karst geology, hydrology and geomorphology, speleology, hydrogeology, biospeleology and history of karst science.&nbsp;<em>Acta Carsologica</em> was established in 1955, now it is co-published by the Slovenian Academy of Sciences and Arts and ZRC SAZU Karst Research Institute.</p> <p>Print ISSN: 0583-6050<br>Online ISSN: 1580-2612</p> ZRC SAZU, Založba ZRC en-US Acta Carsologica 0583-6050 <p><span style="font-weight: 400;">Authors guarantee that the work is their own original creation and does not infringe any statutory or common-law copyright or any proprietary right of any third party. In case of claims by third parties, authors commit their self to defend the interests of the publisher, and shall cover any potential costs.</span></p> <p><span style="font-weight: 400;">More in: <a href="">Submission chapter</a></span></p> Development model of rock relief on thick horizontal and gently sloping rock strata exposed to rain <p>Due to various factors influencing diverse rocks, karst phenomena take unique shapes that are most often reflected in the rock relief. Through a series of different developmental factors, new factors first gradually transform the traces of old formations and over time, if they are distinct enough, they can replace them with completely new ones. In places old forms are reflected in the formation of a new rock relief only indirectly. The rock relief of karst phenomena, in this case karren, also develops under the influence of a single factor. Developmentally, rock forms, due to dissection of the surface and lasting of development, often in several layers merge into one another. A development model enables us to discover the overall development of the formation of the selected part of the rocky karst surface. The individual rock forms which have merged into the rock relief represent just one stage of development. Good knowledge of the overall development enables us to discern the development so far and predict future development. A number of development models can be discerned. One of the basic models reveals the manner of the rain-induced formation and development of horizontal and gently sloping carbonate rock strata into karren and stone forests, especially after the disintegration of the upper (thinner) rock strata and the denudation and shaping of the bottom strata. It reveals many characteristics of rock formation, from the sheet flow to the formation of rain flutes, their merging into rain channels and the development of funnel-like notches; that is, developmental transition of rock forms and rock relief in the overall development from the flat surface to its dissection into peaks.</p> Martin Knez Tadej Slabe Leon Drame Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.9308 Geodiversity of surface karst features of geographical zones <p>&nbsp;The diversity of small, medium, and large solution features of zonal karsts and high mountain karsts is described here. It was taken into consideration how diversity changes according to the distance from the Equator in case of small, medium and large features of various zonal karsts and how it varies based on the distance from altitude in case of the karren features (small features) of high mountain karsts. It can be established that the diversity of karst features decreases according to the distance from the Equator (independent of the size of the features), while in high mountains the diversity of karren features first increases with altitude and then it decreases. The decrease of the diversity of medium and large features moving away from the Equator can be explained by the decrease of dissolution in­tensity. The diversity change of karren features shows a rela­tion with the diversity of the inclination of the bearing slope. Since on tropical karsts and in the medium elevated areas of high mountains (1600-2100 m) where bare slopes with large expansion and various slope inclination occur, the diversity of karren is great. On tropical karsts, slopes with diverse inclina­tion were created by karstification and in high mountains by glacial erosion.</p> Veress Márton Szilárd Vetési-Foith Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.10082 Ice in caves and its effect on thermal inversion and permafrost in the case of the Velika ledena jama v Paradani, Smrekova draga and neighbouring dolines <p>In the Velika ledena jama v Paradani, in the karstic blowholes on the slopes of Smrekova draga and in the nearby dolines I measured and interpreted air temperatures and the effect of the summer outflow of cold air from them into the surrounding area. In winter, cold air enters the cave, radically cooling the entrance part of the cave, where for this reason there is permanent cave ice. The summertime circulation is reversed: emerging from the inner part of cave, which has an average temperature of around 4° C, is air which only when it transits through the sub-cooled entrance part is then cooled to around 1° C. This air comes to the surface and in the hollow at the cave entrance maintains a distinct thermal inversion during the warm part of the year. There is a similar air circulation and similar development of annual temperatures observed at the vents, where cave air emerges through rubble spread over cave entrances on slopes or at the bottom of dolines. The stable summer air temperatures of around 1° C in the vents where I conducted measurements indicate that underneath them there is also permafrost or sub-cooled rock and permanent ice. This is created and preserved, just like in the caves, due to the advection of cold air in winter. In Trnovski gozd, such karstic permafrost is found at an altitude of 1,100 m above sea level. The outflow of cold air from the vents in the summer, just like inside the cave, causes a distinct thermal inversion in dolines on the surface.</p> Andrej Mihevc Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.10495 Evaluating carbonate dissolution and precipitation in a short time-frame using SEM: techniques and preliminary results from Postojna Cave, Slovenia <p>Carbonate dissolution and precipitation are important geological processes whose rates often require quantification. In natural settings, these processes may be taking place at a slow rate, and thus, it may not be easily visible which of these processes is occurring. Alternatively, if the effects of precipitation/dissolution are visible, it may not be clear if they are still underway or an artefact of past conditions. Moreover, these two opposing processes may flip states depending on the environmental conditions, such as, on a seasonal basis. Here, we present the technical details and preliminary results of a method using carbonate tablets and Scanning Electron Microscopy (SEM) to evaluate which process (carbonate dissolution or precipitation) is occurring, using as an example, a cave environment. Our method involves making tablets by encasing blocks of carbonate rock into resin and polishing these to form a completely flat and smooth “zero surface”. These tablets are observed under SEM in exactly the same points both before and after exposure to the field environment, using a system of marking lines at specific locations on the resin. Our results show significant differences in the before and after images of the tablet surface after just six weeks in the cave. Furthermore, the use of the insoluble resin zero surface permits a comparison of the starting height with the new dissolved/precipitated surface that can be used to quantitatively estimate the rate of dissolution/precipitation happening at a field location in a relatively short time-frame (weeks/months). This method could be used in numerous natural and industrial settings to identify these processes that can be caused purely geochemically, but also through microbialmediation and physical weathering.</p> Vanessa Johnston Adrijan Košir Andrea Martín Pérez Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.9788 Impact of visits on the microclimates of caves, Experimental evidence from Škocjan Caves <p>Tourism activities in caves can result in changes in the microclimates of caves. The natural microclimate in closed caves is constant due to the balance between cave air and cave walls, while in open caves exchanges with outside air influence the microclimate. Visits to caves, especially in closed smaller caves, can thus endanger the natural balance if the microclimate does not return to natural conditions quickly enough.<br>Continuous monitoring of the temperature and concentration of carbon dioxide in Škocjan Caves enables the assessment of the impact of visits. For this purpose, we used data measured in the relatively closed Silent Cave, at the locations named Calvary (Kalvarija), Tent (Šotor), and Passage (Prehod) in 2016, and in the wide open Murmuring Cave, at the locations named Bridge (Most) and Rimstone Pools (Ponvice), in 2013. The outdoor air temperature, as measured at the Škocjan meteorological station on the surface plateau, was considered in both cases.&nbsp;Along the tourist part of Škocjan Caves, the most closed part of the cave in Silent Cave is the location at Calvary, when the entrance doors through an artificially dug tunnel are closed. During the visits, the microclimate is subjected to draughts through open doors and to anthropogenic emissions. The data suggest that the influence of draughts predominates over direct anthropogenic emissions. In winter or on cold days air flows upwards and through the tunnel out of the cave, whereas in summer or on warm days it flows downwards. In such cases, the CO<sub>2</sub> concentration decreases markedly due to the downwards chimney effect as the concentration in the outside air is much lower than in the cave. The data show that the temperature overnight and towards morning always returns to its natural value even in this</p> <p>rather small location in the cave. The changes in CO2 concentration persist for a longer period, until the time of the first visit the next morning, when it is again perturbed by a new visit. The data on time courses support the theoretically estimated characteristic of the exponential decline of disturbances backward towards natural conditions, depending on the size of a cave and on the efficiency of exchanges with its walls. For tem­perature, this characteristic time tT is about three to six hours at the Calvary site. The return of CO<sub>2</sub> to natural conditions tCO2 is longer and its estimate less reliable than the one for temperature. In the wide-open and large Murmuring Cave, the impact of visits is negligible throughout the year. In this part of the cave we can observe the influence of external daily and annual changes, the amplitudes of which get smaller, and their phase lags bigger, deeper in the cave.</p> Vanja Debevec Jože Rakovec Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.7397 Potential influence of a planned landfill on a high karst plateau in Southwestern Montenegro to nearby karstic springs <p>The potential threat of a landfill projected on a high karst plateau in southwest Montenegro is investigated with respect to the subjacent nearby springs. The locality is called Duboki do. As the springs are used for drinking water supply this investigation is urgently needed. For the springs exist two hypotheses concerning their catchment area: I) from the high karst plateau, or II) from a topographically lower area. The stable H- and O-isotope ratios of water samples from the springs are compared with precipitation isotope data, to reveal the catchment area of the springs. The isotope results indicate that the catchment area of the springs is at higher altitude fitting to, and in good agreement with, winter precipitation from the high karst plateau of the planned land-fill locality.</p> Micha Horacek Milan Radulovic Dejan Jancic Stefan Wyhlidal Golub Culafic Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.7711 Vulnerability mapping of karst springs and its application for the delineation of protection zones (Mecsek Karst, Hungary) <p>Over the past decade or two, vulnerability mapping become a useful tool to determine the sensitivity of karst aquifers and allows the analysis of karstic aquifers affected by human activities. The Tettye Catchment, one of the eight catchments of the Mecsek Karst aquifer (SW Hungary), supplies drinking water for Pécs, the fifth most populous city in Hungary. However, due to its partly urbanized character and heterogeneous karstic features, this catchment is highly sensitive to anthropogenic impacts. In this study we aimed to generate resource vulnerability maps and risk maps to assess the role of physical and anthropogenic factors on groundwater vulnerability in the Mecsek Karst. Two formerly validated methods were used, the COP (Concentration, Overlaying layers and Precipitation) and SA (Slovene Approach) methods. The resource vulnerability maps, validated by former tracer tests, were combined with the hazard map obtained from the COST action 620 and EU Water Directive to generate risk maps. Tracer-based transit times were commonly less than 20 days in the majority of the areas of extreme vulnerability. During the current study, a new protocol has been elaborated for the delineation of the protection zones of karstic aquifers. Comparing the two methods, the SA performed better in terms of intrinsic vulnerability mapping, as it had a higher spatial resolution and was more detailed than the COP map and had a more sophisticated vulnerability indexing. In addition, high spatial correlation was revealed between the transit time maps and the SA map. Reassessed risk zonation, with appropriate legal consequences, likely minimizes undesired human activities within the zone of protection, hence maintaining water quality that complies with the protection acts</p> Éva Farics Amadé Halász Szabolcs Czigány Ervin Pirkhoffer Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.8583 Gregarines (Apicomplexa: Eugregarinorida) parasitizing the cave cricket Troglophilus (Orthoptera: Raphidophoridae) in the Slovenian karst <p>The cave crickets <em>Troglophilus neglectus </em>Krauss, 1879 and <em>T. cavicola </em>(Kollar, 1833) originating from caves in Slovenia were surveyed for gregarines. Two gregarine species were identified. <em>Gregarina troglophili </em>(Golemansky &amp; Lipa, 1991) occurred in both cave cricket species, <em>T. cavicola </em>being reported a new host species. Besides, a new species, <em>Gregarina bernardae </em>sp. n., in­fecting <em>T. neglectus</em>, was identified and described. The two spe­cies often infest the same <em>T. neglectus </em>individuals, but can be well distinguished upon the shape and morphometric indexes of both solitary gregarines and associations. The deutomerite in solitary gamonts of <em>G. troglophili </em>is orbicular to broadly el­liptoid, while in <em>G. bernardae </em>sp. n. it is oblong to dolioform. In associations, the primite deutomerite in <em>G. troglophili </em>is orbicu­lar to broadly elliptoid, while in <em>G. bernardae </em>sp. n. it is shal­lowly oblong to oblong. In contrast to broadly obovoid to finely obdeltoid satellite deutomerite in <em>G. troglophili</em>, it is narrowly dolioform or dolioform to narrowly obdeltoid in <em>G. bernardae </em>sp. n. Both species are new to the faunal list of Slovenia, and to the list of cave-dwelling species in the country. We direct the attention to the parasite diversity of cave-dwelling animals – a promising, but understudied topic that might considerably contribute to the diversity of the subterranean fauna.</p> Dušan Devetak Tone Novak Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.9305 Comparation study of soil genetic diversity of bacteria and fungi in different vegetation successions in a karst of Guizhou province, China <p>To study the soil genetic diversity of bacteria and fungi in different vegetation successions (grassland, shrubbery, primary forest and secondary forest) from the karst area, the Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) technology was applied. The results showed that: (1) the diversity of bacterial communities and the fungal communities in karst area were higher than non karst area in each vegetation succession. Compared with the survey from bacterial (the Shannon index was 2.97 in primary forest, 2.91 in secondary forest, 3.18 in shrubbery, 3.14 in grassland and 2.68 in non karst), fungal diversity between karst areas (the Shannon index was 3.56 in primary forest, 3.78 in secondary forest, 3.73 in shrubbery and 3.70 in grassland) and non karst areas (the Shannon index was 3.08) was more evident, which may be related to the alterations of the composition of plant community and the source of carbon in soil with the vegetation succession of karst ecosystem; (2) The comparation of bacterial diversity index and the richness comprehensively evaluated as follows: shrubbery &gt; grassland &gt; primary forest &gt; nsecondary forest. The diversity index and the richness of fungal communities was as follows: secondary forest &gt; shrubbery &gt; grassland &gt; primary forest. The results suggest that the fungal communities have been greatly changed via vegetation successions, but the diversity index and the richness of the bacterial communities have not been seriously affected. The results provide scientific basis for understanding karst surface ecosystem, which contributes to the future aim of protecting the karst from desertification.</p> Yidong Mi Hongda Fang Tao Peng Min Zhou Xinru Li Fanfan Wang Haiyan Chen Hailei Su Yuanrong Zhu Yuan Wei Lin Xi Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.7684 First letter from E. A. Martel to Jovan Cvijić: the beginning of mutual collaboration <p>The Archive of the Serbian Academy of Science and Art in Belgrade includes four letters, a picture postcard and a plain postcard sent by Édouard-Alfred&nbsp; Martel to Jovan Cvijić. This correspondence covers the period from 1895 to 1925.</p> Jasminko Mulaomerović Jasmina Osmanković Copyright (c) 2021 ZRC-SAZU 2021-12-15 2021-12-15 50 2-3 10.3986/ac.v50i2-3.10451