Comparison of historical and current temperatures in show caves (Slovenia)

Historical air temperatures at three karst caves in Slovenia have been compared to current data time series. In Postojnska Jama (PJ), the most visited show cave in Slovenia, the significant temperature difference between historical and modern measurements at the Pulpito site relates to the months April to November. Mean monthly temperatures measured at the Sepolcro site (PJ) in the modern period (2016–2019) are year round significantly higher than in the historical period (1935–1937). The temperature increase over the last 85 years in PJ is attributed to outside temperature rise and additional heat input from visitors, especially for Sepolcro site. A comparison of current (2017–2019) and historical (1956–1957) temperature data in touristically poorly visited Predjama Cave shows lower increase as in PJ and is completely related to outside cave conditions. In the case of Škocjanske Jame (Tiha Jama), air temperature has not significantly increased since the historical 1928 measurements because the monitoring site looks to be morphologically isolated from significant impacts of outside climate and visitors.

Leplat, J., François, A. & Bousta, F. (2021) Simplicillium pech-merlensis, a new fungal species isolated of the Pech-Merle show cave. Phytotaxa 521 (2): 80–94.

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Simplicillium pech-merlensis, a new fungal species isolated from the air of the Pech-Merle show cave

An original fungal strain has been recovered during an aerobiological survey in the Pech-Merle show cave (France). The use of multi-locus (ITS, LSU, SSU RPB1, RPB2 and TEF-1α) phylogenetic analysis of the strain by maximum likelihood and by Bayesian inference coupled with a morphological characterization allowed us to place it in the Simplicillium genus as Simplicillium pech-merlensis sp. nov. This new species seems morphologically close to S. calcicola and S. album, which were also first isolated from a cave habitat. This paper discusses the phylogenetic place of S. pech-merlensis and some other species in the genus Simplicillium.

Paracoccus onubensis sp. nov., a novel alphaproteobacterium isolated from the wall of a show cave

A novel facultatively anaerobic, non-motile, Gram-stain-negative, non-endospore-forming alphaproteobacterium, strain 1011MAR3C25T, was isolated from a white biofilm colonizing the walls of the Andalusian show cave Gruta de las Maravillas (Huelva, Spain). Strain 1011MAR3C25T grew at 8–42 °C (optimum, 20–30 °C), at pH 5.0–9.0 (optimum, pH 5.0–6.0) and in the presence of 0–12 % (w/v) NaCl (optimum 3–5 %). Cells were catalase- and oxidase-positive. The strain grew heterotrophically with various carbon sources and chemoautotrophically with thiosulfate under aerobic conditions. Results of phylogenetic analysis showed that strain 1011MAR3C25T was related to Paracoccus saliphilus DSM 18447T and Paracoccus alkanivorans LMG 30882T (97.90 % and 97.32 % 16S rRNA sequence identity values, respectively). The major respiratory quinone was ubiquinone Q-10 and the predominant fatty acid was C18 : 1 ω7c. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid, an unidentified glycolipid and an unidentified polar lipid. The DNA G+C content was 60.3 mol%. Based on a polyphasic taxonomic study it is proposed that strain 1011MAR3C25T (=CECT 9092T=LMG 29414T) represents a novel species of the genus Paracoccus , for which the name Paracoccus onubensis sp. nov. is proposed.

Lampenflora in a Show Cave in the Great Basin Is Distinct from Communities on Naturally Lit Rock Surfaces in Nearby Wild Caves

In show caves, artificial lighting is intended to illuminate striking cave formations for visitors. However, artificial lighting also promotes the growth of novel and diverse biofilm communities, termed lampenflora, that obtain their energy from these artificial light sources. Lampenflora, which generally consist of cyanobacteria, algae, diatoms, and bryophytes, discolor formations and introduce novel ecological interactions in cave ecosystems. The source of lampenflora community members and patterns of diversity have generally been understudied mainly due to technological limitations. In this study, we investigate whether members of lampenflora communities in an iconic show cave—Lehman Caves—in Great Basin National Park (GRBA) in the western United States also occur in nearby unlit and rarely visited caves. Using a high-throughput environmental DNA metabarcoding approach targeting three loci—the ITS2 (fungi), a fragment of the 16S (bacteria), and a fragment of 23S (photosynthetic bacteria and eukaryotes)—we characterized diversity of lampenflora communities occurring near artificial light sources in Lehman Caves and rock surfaces near the entrances of seven nearby “wild” caves. Most caves supported diverse and distinct microbial-dominated communities, with little overlap in community members among caves. The lampenflora communities in the show cave were distinct, and generally less diverse, from those occurring in nearby unlit caves. Our results suggest an unidentified source for a significant proportion of lampenflora community members in Lehman Caves, with the majority of community members not found in nearby wild caves. Whether the unique members of the lampenflora communities in Lehman Caves are related to distinct abiotic conditions, increased human visitation, or other factors remains unknown. These results provide a valuable framework for future research exploring lampenflora community assemblies in show caves, in addition to a broad perspective into the range of microbial and lampenflora community members in GRBA. By more fully characterizing these communities, we can better monitor the establishment of lampenflora and design effective strategies for their management and removal.

The pattern of the tectonic joints and the development of the Vlychada karst show cave in Diros, Peloponnesus, Greece

<p>The most characteristic feature of carbonate rocks is that they are prone to dissolution due to the meteoric water circulation which is enriched in CO<sub>2</sub>. One of the factors influencing this phenomenon is the existence of discontinuities within the mass of carbonate rocks. The Diros Vlychada show cave, on the peninsula of Mani in Peloponnese, Greece, has developed in marbles that belong to the Plattenkalk geotectonic unit. Most of the cave is flooded with water and its level changes depending on the external weather conditions and variations in sea level. The deformation of the marbles is represented by tectonic structures formed during the Lower Miocene metamorphism and their subsequent exhumation. The final uplift stage took place during the Pliocene-Quaternary and is still active. Five joints systems were distinguished:</p><p>A NW-SE joint system which is subdivided into a subsystem with low-angle dips, mainly towards to the NW, related to the main foliation of the marbles and a second subsystem characterized by stretching joints of the same strike (elongated joints), which have high-angle dips, also towards the NW. The latter system intersects the former but is confined between marble bedding and does not extend to more than three beds (the bedding is defined by the first subsystem).</p><p>A NW-SE striking joint system characterized by stretching joints with high-angle dips, which intersects diagonally the two previous. This system extends between more than three marble beds.</p><p>Two systems show E-W and N-S strike with the first one much better expressed. Those joints have developed diagonally to the previous ones. These are mainly shear joints that intersect the first system and are propagated within many marble beds.</p><p>The chambers of the cave have been developed along NW-SE and E-W directions. The first one is identified with the joint system that has been developed transversely to the strike of the marble foliation and the second in parallel with the main system of the shear joints. It is interesting that the bays forming the coastline of the Mani peninsula, have developed in an E-W direction, which coincides with both one of the growth directions of the cave and one of the joints systems, which correspond to shear joints developed during the folding of the marbles. Stalactites and stalagmites grow in a NE-SW direction that is identical to the elongated joints which form the system that is parallel to the foliation strike. Groundwater flow along these branches may be slower as these branches appear to be restricted between marble bedding.</p>

Show cave websites in Serbia: Evaluation and potential improvements

Show caves and speleotourism can have a major impact on the tourism industry as well as the local and regional economic development. Promotion is a crucial aspect of generating plans and strategies for tourist caves. In the case of speleotourism, promotion needs to be professional, attractive and continuous because caves are often considered to be dangerous and inaccessible places. The main goal of this paper is to determine the quality of official show cave websites in Serbia. The assessment included the application of modified Website evaluation model. Website design techniques were also assessed, including the performance and the degree of optimization for search engines SEO. The results show extreme deficiencies and weaknesses regarding the level of internet promotion of Serbian show (tourist) caves. These results are of great importance for cave management teams and tourist organizations because they point out the negative factors of cave promotion in Serbia that need to be revised.

The study of amphipods in rimstone pools of Akiyoshi-do Cave, Japan

Akiyoshi-do Cave is the largest show cave in Japan and has been recognised as a hotspot of cave animals due to their diversity in species. Human-induced alterations in the cave environment have been a significant concern catching the attention of tourists and managers. Previous studies indicated water quality alteration induced by tourism could affect the population densities of amphipods. However, no study went further than qualitative observation in terms of human impacts. This study targets two amphipods living in Akiyoshi-do Cave, Pseudocrangonyx akatsukai and Gammarus nipponensis and measures water characteristics in which they live. Results show that the population densities of the amphipods have decreased compared to the 1970s. Their living habitat has changed, probably induced by tourism.