Cave Entrance Research Articles

A Schistostega pennata (Bryophyta) spore devourer in flagranti—a troglophyle mite Kunstidamaeus lengersdorfi (Acari, Oribatida: Damaeidae)

This is the first record of the intentional consumption of moss spores by an arthropod. A moss mite Kunstidamaeus lengersdorfi (Oribatida: Damaeidae) was observed in Moscow Province, Russia, as regularly visiting mature capsules of the moss Schistostega pennata (Schistostegaceae) and eating spores from the opened capsules. The spores of Schistostega are thin-walled, sticky, not dispersed by wind, and exposed at the capsule mouth for easy consumption, being very similar in this respect to the spores of the entomochorous mosses of the Splachnaceae family. Walking through Schistostega population, these mites carry a lot of its spores of their bodies. According to published data, Kunstidamaeus is mostly feeding on saprotrophic fungi and green algae. Behavioral observations as well as the gut content study show that Kunstidamaeus lengersdorfi can also feed on spores of Schistostega pennata. This is the first record of Kunstidamaeus lengersdorfi in Russia. Previously it was known in Central Europe at cave entrances. In a parallel way, Schistostega grows in Central Europe mostly in caves, while it recently explosively spread in boreal, especially spruce-dominated forests in the Central European Russia. The available data indicate that the mite range expansion had followed the expansion of its forage plant.

Human-induced Alterations of the Mycobiota in an Alpine Show Cave (Italy, SW-Alps)

Anthropogenic alterations in show caves are well documented in scientific literature. One of the main sources of perturbation derives from visitors, acting as carriers of propagules and organic matter in the cave ecosystems. Such perturbation generally results in a significant alteration of the natural subterranean microbiota. In this study, we characterize the mycobiota of the superficial alluvial sediment (0–5 cm) of the Bossea show cave (NW-Italy) over two sampling seasons, aiming to investigate whether anthropogenic rather than natural factors contribute to the colonization and proliferation of alien mycobiota in the cave environment. We placed eighteen sampling plots at different distances from the touristic pathway that crosses the cave. The distance from the touristic pathway was used as proxy to sort the sampling plots in three groups according the degree of anthropogenic disturbance (high: 0–2 m; intermediate 2–40 m; low: >100 m). Moreover, in order to elucidate the potential effect of other factors, we introduced in our analysis the distance from the subterranean river and the distance from the cave entrance. In each plot, we collected two samples of alluvial sediment, in winter and summer. Fungi were isolated from each sample and identified by means of an integrated morphological approach. We observed a rich and diversified fungal community – 63 taxa of Zygomycota and Ascomycota plus several unidentified yeasts – consisting of both native and alien species. Regression analysis points out a decrease of the abundance and the diversity of viable propagules at increasing distances from the touristic pathway rather than the cave entrance or the subterranean river. Accordingly, the exogenous organic materials passively conveyed by tourists, possibly explains the higher proliferation of alien species in the proximity of the touristic pathway. There was also a seasonal variation in the diversity and abundance of propagules, which we interpreted in light of the peculiar microclimate of the cave. In a second step, we used Indicator Species Analysis to identify the most representative species of the different levels of anthropogenic disturbance. In particular, Aspergillus spelunceus was found to be indicator of low disturbance, whereas Mucor corticola and A. asperescens were found to be indicators of intermediate and high disturbance, respectively. Key words: anthropic disturbance, alluvial sediment, alien species, airborne fungi, environmental impact.

Mixed effects of gating subterranean habitat on bats: A review

ABSTRACTCaves and abandoned mines, roosting environments for many bat species including subterranean obligates, are under human pressure (e.g., recreation) and pose threats to humans. Gating entrances of these subterranean features prevents human entry while protecting habitat for bats. However, bat response to these gates is not well understood and no comprehensive synthesis with species‐specific recommendations on protection measures for bat roosts exists. We reviewed literature on effects of gating subterranean habitat on bats and roost microclimate and found 22 studies and reports from North America, Australia, Europe, and Asia. Ten studies examined effects of gating on bat use, 9 described behavioral responses to gates, and 5 presented effects of gates on roost microclimate. Older gate designs (1950–1970), such as cement walls or iron doors, negatively affected bat use and roost microclimate, but responses to modern (1970s to present), bat‐compatible gate designs varied. Short‐term responses of bats to bat‐compatible gates were negative and included increases in energetically expensive flight behaviors. Although long‐term responses included a mix of population and species trends, we attribute these mixed responses in part to differences in flight agility among species. Bats with moderate to high agility (low wing loading, broad call bandwidths) adjust to gates, but species with low agility (high wing loading and narrow call bandwidths) may abandon sites after gating. Other factors including bat density in roosts and size of the cave or mine entrance also affect acceptance of gates and should be considered in gate design. Current gate designs are adequate for most species. Based on available literature, we recommend use of bat‐compatible gates with horizontal bar spacing of 14.6 cm, bar types that offer high structural rigidity in areas where vandalism is likely, and periodic monitoring of gates to ensure they remain in good condition. © 2017 The Wildlife Society.

PCO2 variations of cave air and cave water in a subtropical cave, SW China

Cave CO2 is an important part of the carbon cycle in a karst system. From 2008 to 2009 the partial pressure of CO2 (PCO2) of the cave air and cave water (cave stream and dripwater) in Xueyu Cave was studied. The PCO2 for cave air and cave water over two years showed that CO2 concentrations vary seasonally in all field sites, with higher CO2 concentrations in the wet season and lower concentrations in the dry season. These seasonal CO2 variations of cave air and cave water are attributed to seasonally variable soil CO2 production that is controlled by outside temperature fluctuations. Cave ventilation controls synchronous sharp variations of PCO2 from wet season to dry season or dry season to wet season in cave water and cave air. In the wet season, there were no obvious spatial differences of mean PCO2 in cave stream and cave air from upstream to downstream cave. Conversely, there were significant spatial differences of mean PCO2 in cave stream and cave air from upstream to downstream cave in the dry season because of cave ventilation. Mean dripwater PCO2 in D1 site where near cave entrance is much higher than that of the D2 and D3 sites where located in inner cave because D1 has a shorter flowpath from cave ceiling to soda-straw tip and lesser CO2 degassing along the flowpath. Further work in Xueyu Cave needs to clarify the quantitative relationship of CO2 cycle between cave air CO2 and cave water and focus on the influence of CO2 cycle on speleothem form.

Evidence of Holocene surface and near-surface palaeofires in karst caves and soils

Black deposits covering speleothems, cave walls and floors in Postojna Cave and Predjama Cave (SW Slovenia), and charcoal found in soil outside the Postojna Cave, were studied in order to establish their origin and age. SEM/EDS analysis of these deposits from both caves indicated that they are charred plant remains, very similar to oxidised charcoal in soil. Stable carbon isotope δ13C values of −29.41‰ (Črna Jama, P1), −26.9‰ (Predjama), and −25.1‰ (charcoal in soil) confirm their origin from biomass burning. Radiocarbon dating from Postojna Cave (Črna Jama (P1) 8394±35calyrB.P. and Pisani Rov 8235±25calyrB.P.) suggests that the oldest analysed black deposits formed in the Early Holocene (Mesolithic). The age is consistent with soil charcoal found at 1m depth in the surrounding area. Black deposits from Predjama were dated to 4095±25calyrB.P. (Eneolithic) and were caused by burning fires at the cave entrance, as supported by archaeological remains. Prehistoric (2375±20calyrB.P.) charcoal from the upper part of the soil profile (0.5 to 0.6m) and historic (1240±29calyrB.P. or 745calyrCE) black deposits from Postojna Cave (Črna Jama, P2) are related to forest fires, which are most likely human-induced. We interpret the oldest dated black deposits in Postojna Cave as traces of Early Holocene natural forest fires, since fire activity inside Črna Jama and Pisani Rov is not supported by archaeological remains. Favourable cave entrance morphology and microclimate allowed smoke to enter the cave during the winter period and deposit on speleothems. But an anthropogenic cause of forest fires cannot be excluded, since there are well-documented Mesolithic archaeological cave sites located close to the area. The study shows that black deposits on speleothems in caves are an important palaeoenvironmental record and proxy for Holocene climate.

Quaternary depositional facies in cave entrances and their relation to landscape evolution: The example of Cuvieri Cave, eastern Brazil

The correct determination of sedimentation processes in caves is often complicated by the unique characteristics of cave environments and their relationship to surface soil. A study at Cuvieri Cave has allowed new insights into the dynamics and evolution of these types of sedimentary facies and their relation to the nearby landscape. The cave is located in the Lagoa Santa Karst, eastern Brazil, and contains fossiliferous deposits of Pleistocene–Holocene age at the base of three vertical pits near the cave entrance. Facies analysis was applied to sediments to understand sedimentation process, and sediments were described according to their morphology, grain-size, micromorphology, chemical composition, paleontological content and age. Results indicate that all deposits present a soil-like aspect and although they record several depositional conditions, sedimentary structures and textures are similar among different facies. As such, facies were defined by a combination of matrix color, degree of cementation and sedimentological characteristics. Additionally, abundance of fauna remains, their taxonomic composition (extant vs extinct), completeness, and degree of individuals' articulation was evaluated. Differences between facies were produced by two main factors: (i) change in source area and transport route (from the epikarst to doline colluviation and back to epikarst) and (ii) change in type of sediment cover injected, from doline fed soils, followed by talus debris and finally soils from modern epikarst. The change in both factors is related to the landscape evolution, mainly with the development and progressive enlargement and deepening of the nearby doline. Additionally, the change in the type of sediment cover injected could also be related to climatic evolution. The complex evolution of Cuvieri Cave sediments occurred over at least the last 300kyr and is marked by periods in which entrance opening allowed the incorporation of vertebrate (both extinct and extant) remains into the sediment. Detailed multidisciplinary field and laboratory analyses are essential in unraveling the long history of sedimentation in caves, providing a framework in which multiple events of sediment input and erosion can be correctly interpreted and related to the evolution of the landscape.

Diversity and pattern of nest preference of bat species at bat-dwelling caves in Gombong Karst, Central Java, Indonesia

Wijayanti F, Maryanto I. 2017 Diversity and pattern of nest preference of bat species at bat-dwelling caves in Gombong Karst, Central Java, Indonesia Biodiversitas 18: 864-874. A study on the diversity of bat species, their community structure and pattern of roosting preference, has been conducted in twelve caves in Gombong Karst, Central Java. Bats were caught at the roosting place during the day. Length, width, and height of cave passage were measured, as well as a number of entrances and cave’s ventilation were also calculated. In addition, microclimate parameters were measured under the bat roosts. Data were analyzed by ANOVA, Redundancy analysis (RDA) and canonical correspondence analysis (CCA). Fifteen species (eleven species of insectivorous bats and four species of fruit bats) were recorded. The result also shows that the length, height, and width of the cave passage influenced the community structure of bats. While the other physical factors, i.e. sound intensity, distance from the cave entrance, temperature, humidity, and light intensity influence the bat nesting preference. Furthermore, there were five groups of bats which have a specific pattern of roosting preference.

Quantifying meso‐mammal cave use in central Texas

Knowledge of meso‐mammal cave use is essential for natural resource managers, particularly in the management of endangered cave invertebrates. Scat left by meso‐mammals represents significant nutrient inputs into the oligotrophic cave environment which can disrupt the invertebrate species composition and ecology. Since little is known about what constitutes typical timing or frequency of meso‐mammal visitation, current management practices are largely speculative. Central Texas caves were historically associated with raccoons Procyon lotor, but with the loss of large predators and encroachment of woody vegetation, the now naturalized North American porcupine Erethizon dorsatum has become an established part of the local ecosystems whose effect on cave biology remains unknown. Our objective with this study was to quantify meso‐mammal cave use according to seasons, time of day, weather conditions, as well ecological and physical cave characteristics. We monitored 30 caves by placing trail cameras at cave entrances for one year on Joint Base San Antonio‐Camp Bullis military base just north of San Antonio, Texas. North American porcupines, raccoons, and Virginia opossums Didelphis virginiana were the three most commonly photographed meso‐mammals (>87%). All meso‐mammal groups showed significantly different cave use according to season, weather, and cave characteristics. Data suggested most meso‐mammals were using caves for denning while raccoons and Virginia opossums also were feeding on resident invertebrate and rodent populations. In particular, Virginia opossum and raccoon, both potential predators of endangered species, showed greater use of caves containing endangered species. The results from our study represent an initial step in understanding meso‐mammal cave use in central Texas.

Palynology of surface sediments from caves in the Zagros Mountains (Kurdish Iraq): Patterns and processes

Cave palynology has been widely used to reconstruct past vegetation in areas where other conventional sources of pollen are scarce. However, the mechanisms involved in pollen transport, deposition and accumulation in caves are still poorly understood, mostly because of the number of interplaying factors that affect these processes. In this paper we explore some of these factors further by assessing differences in pollen assemblages in transects of surface samples from six caves in the Zagros Mountains of Kurdish Iraq. Simple sac-like caves show a clear pattern in pollen distribution with anemophilous taxa declining from the highest percentages near the front of the cave to lower percentages at the rear of the cave and entomophilous taxa showing the opposite trend. There is a tendency for this pattern to be most marked in caves which are narrow in relation to their length. It is less clear at Shanidar Cave, most probably because of the geometry of the cave but also because of the disturbance and mixing of the superficial sediments caused by the large numbers of people visiting the cave. Only one of the sampled caves shows a different pattern, which is likely to reflect its geomorphological complexity and, consequently, its air circulation. Other factors, such as the presence of a cave entrance flora, are considered but here they seem to have little influence on the pollen assemblages, contrary to that found in temperate-zone caves.

High endemism at cave entrances: a case study of spiders of the genus Uthina.

Endemism, which is typically high on islands and in caves, has rarely been studied in the cave entrance ecotone. We investigated the endemism of the spider genus Uthina at cave entrances. Totally 212 spiders were sampled from 46 localities, from Seychelles across Southeast Asia to Fiji. They mostly occur at cave entrances but occasionally appear at various epigean environments. Phylogenetic analysis of DNA sequence data from COI and 28S genes suggested that Uthina was grouped into 13 well-supported clades. We used three methods, the Bayesian Poisson Tree Processes (bPTP) model, the Bayesian Phylogenetics and Phylogeography (BPP) method, and the general mixed Yule coalescent (GMYC) model, to investigate species boundaries. Both bPTP and BPP identified the 13 clades as 13 separate species, while GMYC identified 19 species. Furthermore, our results revealed high endemism at cave entrances. Of the 13 provisional species, twelve (one known and eleven new) are endemic to one or a cluster of caves, and all of them occurred only at cave entrances except for one population of one species. The only widely distributed species, U. luzonica, mostly occurred in epigean environments while three populations were found at cave entrances. Additionally, eleven new species of the genus are described.

Distribution of meiofaunal abundances in a marine cave complex with secondary openings and freshwater filtrations

Submerged sea caves are priority areas for conservation according to the Habitat Directive 92/43/CEE because of their unique biodiversity. A limited number of publications exist about communities living on sediments inside caves, mostly focused on the macrofaunal fraction (>0.5-mm body size). Meiofaunal communities (0.062–0.5-mm body size) have been largely neglected in ecological studies about communities inhabiting sea caves. In the present study, we analysed meiofaunal communities from Los Cerebros cave, a shallow marine cave (3–8 m in depth, 80 m long), with secondary openings in the inner parts and freshwater infiltrations. Sediment samples were taken by scuba divers using cylinders (cores), with known inner diameter. Sampling stations were sampled from the different sections of the cave (entrance, twilight zone, dark zone and jameos). Five surveys were carried out, from June 2003 to February 2005. Nematodes, copepods, and polychaetes dominated overwhelmingly the meiofaunal composition, with the remaining taxonomic groups being scarce. Generalized linear models showed that the high spatial and temporal variability observed among on the abundance of major meiofaunal groups inside the cave was better explained by the surveys, the section of the caves and the presence of freshwater. Higher abundances are observed near the entrance and in the station with regular freshwater input. Nematodes and polychaetes were clearly dominated by species extensively recorded in shallow subtidal sandy sediments on the study area.

A New Chronology for Rhafas, Northeast Morocco, Spanning the North African Middle Stone Age through to the Neolithic.

Archaeological sites in northern Africa provide a rich record of increasing importance for the origins of modern human behaviour and for understanding human dispersal out of Africa. However, the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb), and their relationship to local environmental conditions, remain poorly understood. The cave of Rhafas (northeast Morocco) provides valuable chronological information about cultural changes in the Maghreb during the Palaeolithic due to its long stratified archaeological sequence comprising Middle Stone Age (MSA), Later Stone Age (LSA) and Neolithic occupation layers. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz grains to the cave deposits of Rhafas, as well as to a recently excavated section on the terrace in front of the cave entrance. We hereby provide a revised chronostratigraphy for the archaeological sequence at the site. We combine these results with geological and sedimentological multi-proxy investigations to gain insights into site formation processes and the palaeoenvironmental record of the region. The older sedimentological units at Rhafas were deposited between 135 ka and 57 ka (MIS 6 –MIS 3) and are associated with the MSA technocomplex. Tanged pieces start to occur in the archaeological layers around 109 ka, which is consistent with previously published chronological data from the Maghreb. A well indurated duricrust indicates favourable climatic conditions for the pedogenic cementation by carbonates of sediment layers at the site after 57 ka. Overlying deposits attributed to the LSA technocomplex yield ages of ~21 ka and ~15 ka, corresponding to the last glacial period, and fall well within the previously established occupation phase in the Maghreb. The last occupation phase at Rhafas took place during the Neolithic and is dated to ~7.8 ka.

Consumption of atmospheric methane in a limestone cave in Indiana, USA

Recent observations suggest that karst landscapes may be an unaccounted sink for atmospheric CH4, but questions remain about the processes contributing to sub-atmospheric CH4 mole fractions in caves. The CH4 dynamics associated with karst environments were studied over 18months at 6 locations in Buckner Cave, Southern Indiana by measuring the mole fractions and stable isotopic composition of CH4 and carbon dioxide (CO2). CO2 mole fractions were used to infer seasonal changes in airflow. Samples were obtained on a monthly basis. CH4 mole fractions ranged from 1.9±0.1ppm near the cave entrance to 0.1±0.1ppm in the more remote parts of the cave. The carbon and hydrogen stable isotopic compositions of CH4 in the cave ranged from −58.7 to +7 ‰ (VPDB) and −170 to +10 ‰ (VSMOW), respectively. The isotopic data suggest that the CH4 dynamics of Buckner Cave can be described by a seasonally variable mixing system in which atmospheric CH4 enters primarily through the main entrance and is subsequently consumed by methanotrophs. Additionally, at least two smaller CH4 sources are evident when air has been stagnant. The results suggest that subterranean karst cavities are an important sink for atmospheric CH4.

Painting Altamira Cave? Shell tools for ochre-processing in the Upper Palaeolithic in northern Iberia

Much of our knowledge of the symbolic world of Upper Palaeolithic hunter-gatherers is based on the study of the graphic representations found in Western European caves. However, to date, few studies have been conducted on rock art apart from chronological and stylistic characterisation. Altamira Cave (northern Iberia) is characterised by an outstanding rock art ensemble, whose representations cover practically the whole Upper Palaeolithic. The site is equally important for the rich Upper Palaeolithic deposits in the cave entrance, which contain large shell assemblages. Traditionally, the presence of shells in hunter-fisher-gatherer settlements has been interpreted as part of the diet and/or the symbolic world (through the creation of ornaments) of these groups, regardless of their possible use as an instrument. In this paper we utilise use-wear methodology, chemical analysis and analytical experimentation to verify the initial hypothesis that shells in the archaeological deposits of Altamira were used to obtain the ochre powder utilised to produce the magnificent and diverse rock art ensemble in the cave. The results provide new information on the process of obtaining pigments for the realisation of paintings and confirm that the use of shells to obtain ochre was a systematic activity throughout the whole study period. Finally, our conclusions support the explanatory model that highlights the role played by marine resources for Upper Palaeolithic human populations.

Faunal remains from an archaic period cave in the Southeastern United States

Ancient Native American use of caves in the Eastern Woodlands occurred throughout the entire span of regional prehistory; however, the ways that these natural features were used varied considerably over time. To date only 25 cave sites containing deposits dated to the Archaic period (ca. 10,000–3000B.P.) are recorded in the state of Tennessee, representing just 0.4% of the total known Archaic sites. In 2014 the authors conducted a salvage operation, bucket auger survey, and limited testing at the site of Black Cat Cave (40RD299) in Rutherford County, Tennessee to assess looting damage and assist in the installation of a security gate across the cave entrance. These investigations identified Black Cat Cave as the site of significant mortuary activity during the Middle Archaic (ca. 6460–6360B.P.), and resulted in the recovery of rare Archaic faunal data from a cave setting. Analysis of faunal materials from the site allows us to add important new information to our understanding of ancient Native American landscape use in the Eastern Woodlands during the mid-Holocene.

Step back! Niche dynamics in cave-dwelling predators

The geometry of the Hutchinson’s hypervolume derives from multiple selective pressures defined, on one hand, by the physiological tolerance of the species, and on the other, by intra- and interspecific competition. The quantification of these evolutionary forces is essential for the understanding of the coexistence of predators in light of competitive exclusion dynamics. We address this topic by investigating the ecological niche of two medium-sized troglophile spiders (Meta menardi and Pimoa graphitica). Over one year, we surveyed several populations in four subterranean sites in the Western Italian Alps, monitoring monthly their spatial and temporal dynamics and the associated physical and ecological variables. We assessed competition between the two species by means of multi regression techniques and by evaluating the intersection between their multidimensional hypervolumes. We detected a remarkable overlap between the microclimatic and trophic niche of M. menardi and P. graphitica, however, the former —being larger in size— resulted the best competitor in proximity of the cave entrance, causing the latter to readjust its spatial niche towards the inner part, where prey availability is scarcer (“step back effect”). In parallel to the slight variations in the subterranean microclimatic condition, the niche of the two species was also found to be seasonal dependent, varying over the year. With this work, we aim at providing new insights about the relationships among predators, demonstrating that energy-poor environments such as caves maintain the potential for diversification of predators via niche differentiation and serve as useful models for theoretical ecological studies.

Biophysical Survey of the Hinatuan Enchanted River Underwater Cave System (HERUCS) and its Connecting River, Surigao del Sur, Southern Philippines

A rapid survey inside the Hinatuan Enchanted River Underwater Cave System (HERUCS) and its connecting river was done to gather baseline data on the biophysical aspects of the cave and river ecosystem. It involved collection of water samples, sediments and macrofauna. Water samples were analyzed for the following parameters, namely: nitrates, phosphates, turbidity, BOD, pH, alkalinity, conductivity and total coliform. Sediment samples were analyzed for total organic matter and grain size. A listing of macrofauna found within the length of the established sampling station was also collected, photo-documented and identified. Water from inside the cave have a pH range of 7.35– 7.39, a BOD of 1.67– 4.00 mg/L, a 16 ppt salinity (at cave entrance), and, nitrate and phosphate values of 0.32 –0.44 mg/L and 0.10–0.52 mg/L, respectively. The mean total coliform count of the water sample from the upstream sampling site was 1,700 MPN/100ml. There were 5 organisms belonging to 4 families recorded from inside the cave while 43 organisms belonging to 9 families were collected from its connecting river. Majority of the macrofauna samples collected were marine to brackish-water species and can be considered accidentals. Although there were no stygobites caught, the possibility of finding new species is high considering the depth of the cave and its many unexplored chambers. Further explorations are highly recommended with the use of mixed gas (i.e., Nitrox) for longer bottom time and more thorough sampling.

Distribution and a comparative analysis of the aquatic invertebrate fauna in caves of the western Caucasus

The freshwater fauna of nine caves in central Abkhazia, western Caucasus, revealed 35 species of stygo bionts, including 15 new species to be described elsewhere. The number of species per station increased from the depth towards the entrance in caves Golova Otapa and Abrskila, becoming the highest in the epigean part. In both caves, two abundance peaks of aquatic invertebrates were registered: one in the entrance area, associated with the development of amphibiotic insect larvae, the other in the depths due to the high numbers of stygobionts. In Cave New Athos, the highest species richness and abundance were observed in large lakes. In caves Golova Otapa and Abrskila, two faunistic complexes with complementary distributions were found, the first due to amphibiotic insects in the cave entrance area, the second one composed of stygobionts in the deep areas. The impact of anthropogenic factors on aquatic cave communities was also noted. The stygobiotic faunas of all caves studied were clearly divided into three groups, following the number of river valleys in which they were situated. The stygobiont faunas of the caves located within one river valley appeared to be 50% similar. In contrast, the fauna composition of the stygobionts from caves situated in different valleys shared not more than 12% species in common. Stygobiotic shrimps and gas tropod mollusks show profound local endemism. Stygobiotic Amphipoda penetrating the ground waters revealed wide distributions between cave systems within a single karst massif.

High-resolution Variations of Oxygen and Hydrogen Isotopes of Precipitation and Feedback from Cave Water: An Example of Jiguan Cave, Henan

The stable isotopes of atmospheric precipitation that affect the isotopes of speleothem and cave water are controlled by a variety of factors, such as temperature, rainfall amount, altitude, vapor source and others. Knowledge in the factors causing rainfall stable isotopes change is one of the keys to understanding the cave water stable isotopes change of monsoon-sensitive area in the north-south China intersection. The samples collected from 4 ground water sites in Jiguan Cave and the instantaneous heavy rain during Aug.4^th-6^th, 2015 were analyzed, and combined with the precipitation oxygen and hydrogen isotopes data for samples from almost 6 years (2009-2015) collected in Jiguan Cave of Luanchuan County in Henan Province, leading to the following findings:① The precipitation was divided into 2 stages with different vapor sources (high-altitude water vapor from the South China Sea and inland areas from near the ground to evaporate moisture) that could be recorded in the δ¹⁸O of single rainfall by HYSPLIT model. ② The evaporation of stage 2 masked the temperature effect to some extent, which also decreased the slope and intercept of LMWL and <i>d</i>-excess of precipitation. ③ The δ¹⁸O values feature of cave drip water in Jiguan Cave during this rainfall was mainly a response to the summer monsoon precipitation from sea source vapor. The cave drip water of Jiguan Cave responded to the heavy rain very quickly, and the time was ~3 h. The δ¹⁸O of drip became heavier when dripping rate increased and then decreased slowly. The same pattern could be found in underground river with slight delay, and the pool near the cave entrance reflected the difference of precipitation δ¹⁸O in two stages.

Linking spatial scale dependence of land-use descriptors and invertebrate cave community composition

Patterns of biodiversity respond to habitat disturbances and different land-uses. Those patterns possibly vary according to the spatial scale under analysis. Although other studies have shown such responses for different systems, no study has ever demonstrated spatial-scale influences in subterranean terrestrial communities. Therefore, the objective of this paper was to analyze how land use and cave physical structure could influence the terrestrial cave invertebrate species composition. We also determined the influence of different spatial scale on the structure of invertebrate cave composition. We collected environmental data at local scale (e.g. cave size, substrate and environmental stability). For spatial scale we determined land uses at three different landscape scales; we gathered these data into circular areas of different sizes (50, 100 and 250 meters) with centroids in the cave entrances. We finally performed three Distance Based Linear Modeling analyses to test for differences among the predictability of environmental variables when comparing different spatial scales. The best explanatory variable for cave invertebrate similarities was the percentage of covering of the external environment by limestone outcrops. We confirm the scale-dependence hypothesis through the different patterns showed among distinct buffer areas. Models become more precise when larger scales were analyzed to explain cave invertebrate composition. This suggests that larger scales capture important environmental features that explain the cave fauna similarities more precisely. Additionally, we found a strong influence of limestone outcrops at all landscape scale structuring cave communities.