Rock Substrate Research Articles

Comparison of Fish Catch Between an Electric Seine and Backpack Electrofishers in Shoal Habitat of the Chipola River, Florida

Abstract We conducted a gear comparison study to determine the best fish-sampling methodology in shoal habitat to assist with the development of a long-term fish community monitoring program on the Chipola River, Florida. Shoal habitat occurs throughout the southeastern United States, is shallow (< 1 m), and contains rock substrate and outcroppings, which limits boat electrofishing to the habitat margins. We compared the relative effectiveness of an electric seine and backpack electrofishers. Twenty-five randomly selected sites (4 m wide by 5 m long) per gear type were block netted and sampled across four shoals from August 28 to October 3, 2014. Habitat variables were recorded for each site. Using backpack electrofishers, 1,155 fish representing 21 species were collected. Using the electric seine, 1,036 fish representing 22 species were collected. We found no significant differences between gear types in mean total catch per site, mean species richness per site, Shannon's diversity, Simpson's dominance, Pielou's evenness, or the rate of species accumulation. Therefore, we consider the two gear types to be equally effective for block-netted sites in large river shoals. Differences in available equipment, funding, and personnel were compared and may ultimately determine which gear type is used in future studies.

Characterization of the Inkaterra rock shelter paintings exposed to tropical climate (Machupicchu, Peru)

During last decades, rock shelter paintings have been described as the most magnificent expression of the scenes of ancient daily lives culture in graphic form. In the scientific field, different analytical techniques have been used for the characterization of different pigments present in the pictographs from rock shelter paintings. Example of this are the Inkaterra rock shelter paintings, which are placed in one of the most impressive and unknown natural setting, located in the town of Aguas Calientes, belonging to the lands of the Hotel Machupicchu Pueblo, forming part of Machupicchu Archaeological Park (Peru) and are composed by many different geometric pictographs. In this work, apart from micro-Raman spectroscopy, X-ray Diffraction (XRD) and Scanning Electron Microscopy coupled to Energy Dispersive Spectrometry (SEM-EDS) have been used to ascertain the molecular and elemental composition of the rock substrate as well as of the different pigments used to create the pictographs visible on the Inkaterra rock shelter. In this sense, black, red and orange pigments were analyzed, identifying the use of carbon, hematite and beta-carotene respectively. Thus, thanks to this work it has been demonstrated that the orange color was not present in the original painting, but it is caused due to microbiological colonizations favored by the climate conditions of the area.

Methods to measure the mechanical behaviour of tree roots: A review

The presence of forests on hillslopes significantly reduces the slopes susceptibility to rainfall triggered shallow landslides. This is due largely to the reinforcement of the hillslope soil by tree roots which increase the shear strength of the soil, and in some instances, anchor the soil mantle to the underlying bedrock by deeply penetrating roots. Quantifying the reinforcing effects of tree roots within soils and the evaluation of hillslope stability using geomechanical and numerical models relies on a realistic representation of the characteristics of tree roots distribution within the hillslope and the mechanical strength of those roots. The variety of experimental methods that have been developed since the 1960s and are used to generate these root strength and rooted-soil shear-strength data are reviewed. The majority of these studies have focused on determining the tensile strength of individual roots by loading the root in a pulling device until it breaks and/or determining the shear-strength of rooted soil in comparison to non-rooted soil in a Coulomb-type shear-box test. These studies have also generally either examined mature root systems in the field or relatively young plants grown in special containers specifically designed for tensile tests or laboratory shear-box tests. A particular difficulty that most studies have encountered is fixing or securing the ends of roots in the attachment device of the testing apparatus (so called root-pullers or tensile testing machines) as the various styles of clamping employed can easily damage the root which reduces the measured strength or otherwise results in an unrealistic test result. Laboratory shear-box tests encounter a similar difficulty in that the roots are not generally fixed or constrained at the base of the shear-box; field shear-box tests tend to avoid this problem as the roots are present in their natural anchoring characteristics in the soil and rock substrate. A result universally reported in rooted soil shear-box test studies is that the peak shear-strength of rooted soil significantly exceeds the peak shear-strength of that soil in a non-rooted condition and that the rooted-soil peak strength is typically recorded at a shear-displacement distance several times that of the non-rooted soil. This result fundamentally explains the reduced susceptibility of forested hillslopes to shallow landslides. A variety of solutions developed to deal with the difficulties that root and rooted-soil tests present are outlined. A set of suggested protocols for conducting root tensile tests and field pullout tests are also presented. It is intended that the adoption of these protocols will enable more effective and direct comparisons of test results and more confident interpretation with respect to the similarities and differences between test results generated from different species and field sites.

It's just sand between the toes: how particle size and shape variation affect running performance and kinematics in a generalist lizard.

Animals must cope with and be able to move effectively on a variety of substrates. Substrates composed of granular media, such as sand and gravel, are extremely common in nature, and vary tremendously in particle size and shape. Despite many studies of the properties of granular media and comparisons of locomotion between granular and solid substrates, the effects of systematically manipulating these media on locomotion is poorly understood. We studied granular media ranging over four orders of magnitude in particle size, and differing in the amount of particle shape variation, to determine how these factors affected substrate physical properties and sprinting in the generalist lizard Eremias arguta We found that media with intermediate particle sizes had high bulk densities, low angles of stability and low load-bearing capacities. Rock substrates with high shape variation had higher values for all three properties than glass bead substrates with low shape variation. We found that E. arguta had the highest maximum velocities and accelerations on intermediate size particles, and higher velocities on rock than glass beads. Lizards had higher stride frequencies and lower duty factors on intermediate particle size substrates, but their stride lengths did not change with substrate. Our findings suggest that sand and gravel may represent different locomotor challenges for animals. Sand substrates provide animals with an even surface for running, but particles shift underfoot. In contrast, gravel particles are heavy, so move far less underfoot, yet provide the animal with an uneven substrate.

Differences in composition of shallow-water marine benthic communities associated with two ophiolitic rock substrata

On marine rocky shores, several physical, chemical and biological processes operate to maintain the benthic assemblages’ heterogeneity, but among the abiotic factors, the composition and texture of the rocky substrata have been only sporadically considered. However, biomineralogical studies have demonstrated an unsuspected ability of the benthic organisms to interact at different levels with rocky substrata. Therefore, the mineralogy of the substratum can affect the structure of benthic communities. To evaluate this hypothesis, the macrobenthic assemblages developed on two different ophiolitic rocks (serpentinites and metagabbros) in contact at a restricted stretch of the western Ligurian Riviera (western Mediterranean Sea), with identical environmental and climatic conditions, were analysed. Samplings were carried out at four bathymetric levels (+1m, 0m, -1m, and -3m respect to the mean sea level) and the analysis of the data evidenced differences in terms of species distribution and percent coverage. Algal communities growing on metagabbros were poorer in species richness and showed a much simpler structure when compared to the assemblages occurring on the serpentinites. The most widely distributed animal organism, the barnacle Chthamalus stellatus, was dominant on serpentinites, and virtually absent on metagabbros. Our results suggest a complex pattern of interactions between lithology and benthic organisms operating through processes of inhibition/facilitation related to the mineral properties of the substratum.

Characterization of diverse coral types using passive acoustic recorded data from the lagoon area of the Kavaratti—An atoll of the Lakshadweep archipelago

The presence of sound in marine habitats can be an indicator of biological processes. Therefore, sound monitoring of the reef system is important to develop an in-depth understanding of the biodiversity, vulnerabilities, and potential changes of ecosystems. In order to understand the diversity related to the coral types, we have computed Acoustic Complexity Index (ACI) (temporal and spectral scales) using passive acoustic recorded data from the lagoon area off the Kavaratti—an atoll of the Lakshadweep archipelago. ACI is found to be the highest in location “A” where the coral type of Acropora sp. and ample fish diversity is observed. In location “C” where massive Porites sp. and Pocillopora sp. with significant acoustic assemblages are observed, ACI was found to be comparatively lower than the location “A.” Whereas for “B,” “D,” and “E” locations, relatively low level of ACI index is obtained. The ACI is the lowest in location “B” where macroalgae with no fish species are seen. Among these three locations, “E” shows higher ACI due to the shrimp sound dominance in the rock substrate having Porite sp. coral type.

Generation of shock lamellae and melting in rocks by lightning‐induced shock waves and electrical heating

AbstractThe very rapid energy release from impact events, such as those resulting from lightning strikes or meteorites, can drive a variety of physical and chemical processes which alter rocks and result in the formation of natural glasses (i.e., fulgurites and tektites). Fulgurite is the vitrified soil, sand, or rock resulting from lightning strikes. A thunderbolt is associated with air temperatures of up to 105 K, which can heat rocks to >2000 K within tens of microseconds. The rapid fusing and subsequent quenching of the surface of the rock leaves a distinctive, thin, garbled coating composed of a glassy to fine‐grained porous material. Previous studies on rock fulgurites found planar deformation features in quartz crystals within the target rock substrate, evidence of strong shock waves during fulgurite formation. In this paper, we simulated the shock pressure and temperature caused by an idealized lightning impact on rocks and compared the model results with observations on rock fulgurites from the literature. Our model results indicate that a lightning strike can cause >7 GPa pressure on the rock surface, generate a layer of fulgurite (of radius ∼9 cm), and leave a burned region (of radius ∼11 cm). The fulgurites found on rock surfaces share many features with sand fulgurites, but their spatial distribution is completely different, as sand fulgurites are hollow tube structures. Our study on rock fulgurites provides an indirect constraint on the energy of a lightning event and also demonstrates that the presence of shock features in rocks cannot be taken as unequivocal evidence for impact events.

Crater stratigraphy and the post-eruptive evolution of Foulden Maar, southern New Zealand

ABSTRACTFoulden Maar, Waipiata Volcanic Field, New Zealand is a partly eroded maar–diatreme formed by phreatomagmatic eruptions c. 23 Ma. Its post-eruptive evolution is reconstructed by combining outcrop, drillcore and physical core rock properties with pollen data. Facies associations in a 190 m thick composite section of the central crater sediments record four depositional stages: (1) immediate post-eruptive deposition of collapsed crater wall and tephra ring material by subaqueous gravity flows; (2) re-deposition of tephra by hyperconcentrated to turbulent gravity flows in a steep-sided lake; (3) seasonally mediated background sedimentation with recurring gravity flows in a meromictic lake; and (4) diminishing turbidity currents under decreasing relief and biogenic sedimentation over c. 130 ka. Clasts in the basal crater fill represent accidental lithic clasts of primary ejecta and indicate eruption into a mixed hard-soft rock substrate. Foulden Maar represents a ‘classical’ lacustrine maar crater sequence and confirms generally similar post-eruptive processes and sedimentation patterns in enclosed, lacustrine maar basins.

Microscale and nanoscale strain mapping techniques applied to creep of rocks

Abstract. Usually several deformation mechanisms interact to accommodate plastic deformation. Quantifying the contribution of each to the total strain is necessary to bridge the gaps from observations of microstructures, to geomechanical descriptions, to extrapolating from laboratory data to field observations. Here, we describe the experimental and computational techniques involved in microscale strain mapping (MSSM), which allows strain produced during high-pressure, high-temperature deformation experiments to be tracked with high resolution. MSSM relies on the analysis of the relative displacement of initially regularly spaced markers after deformation. We present two lithography techniques used to pattern rock substrates at different scales: photolithography and electron-beam lithography. Further, we discuss the challenges of applying the MSSM technique to samples used in high-temperature and high-pressure experiments. We applied the MSSM technique to a study of strain partitioning during creep of Carrara marble and grain boundary sliding in San Carlos olivine, synthetic forsterite, and Solnhofen limestone at a confining pressure, Pc, of 300 MPa and homologous temperatures, T∕Tm, of 0.3 to 0.6. The MSSM technique works very well up to temperatures of 700 °C. The experimental developments described here show promising results for higher-temperature applications.

Use of Wind Fetch and Shoreline Relief to Predict Nearshore Substrate Composition in a North Temperate Lake

AbstractSpawning habitat assessments often focus on substrate composition, but few studies have predicted shoal substrates by using environmental factors. We developed a model for predicting shoal substrates in Belle Lake, Minnesota, using wind fetch and shoreline relief characteristics. Percent composition of four substrate classes (silt, sand, gravel, and rock), water depth estimated at 1 m from shore (shoal slope), effective wind fetch measured using a GIS model, and riparian bank height derived from LIDAR imaging were determined at 50 transects. Classification and regression tree (CART) analysis grouped substrates into categories, and general additive modeling described the effects of three predictor variables on the percent composition of substrate classes. The CART analysis correctly grouped 39 of 50 transects into four categories, and misclassifications primarily resulted from the movement of sand. Effective fetch most influenced silt (low fetch) and rock (high fetch) substrate classes, shoal slope was predictive of rock, and riparian height was useful in distinguishing sand from gravel. These results demonstrate the utility of a single empirical model for determining shoal substrate composition. Fisheries managers can use this technique to determine potential fish spawning locations and identify potential areas for habitat restoration or protection projects.Received December 5, 2016; accepted May 5, 2017 Published online July 19, 2017

Variation in subsurface thermal characteristics of microrefuges used by range core and peripheral populations of the American pika (Ochotona princeps).

Microrefuges provide microclimates decoupled from inhospitable regional climate regimes that enable range‐peripheral populations to persist and are important to cold‐adapted species in an era of accelerated climate change. However, identifying and describing the thermal characteristics of microrefuge habitats is challenging, particularly for mobile organisms in cryptic, patchy habitats. We examined variation in subsurface thermal conditions of microrefuge habitats among different rock substrate types used by the American pika (Ochotona princeps), a climate‐sensitive, rock‐dwelling Lagomorph. We compared subsurface temperatures in talus and lava substrates in pika survey sites in two US national park units; one park study area on the range periphery and the other in the range core. We deployed paired sensors to examine within‐site temperature variation. We hypothesized that subsurface temperatures within occupied sites and structurally complex substrates would be cooler in summer and warmer in winter than unoccupied and less complex sites. Although within‐site variability was high, with correlations between paired sensors as low as 47%, we found compelling evidence that pikas occupy microrefuge habitats where subsurface conditions provide more thermal stability than in unoccupied microhabitats. The percentage of days in which microhabitat temperatures were between −2.5 and 25.5°C was significantly higher in occupied sites. Interestingly, thermal conditions were substantially more stable (p < .05) in the lava substrate type identified to be preferentially used by pikas (pahoehoe vs. a'a) in a previous study. Our study and others suggest that thermal stability appears to be the defining characteristic of subsurface microrefuges used by American pikas and is a likely explanation for enigmatic population persistence at the range periphery. Our study exemplifies an integrated approach for studying complex microhabitat conditions, paired with site use surveys and contextualized with information about gene flow provided by complementary studies.

Icariin promotes proliferation and osteogenic differentiation of rat adipose-derived stem cells by activating the RhoA-TAZ signaling pathway.

Icariin, the main active flavonoid glucoside isolated from Herba epimedii, has been demonstrated to be a potential alternative therapy to prevent postmenopausal osteoporosis. Icariin has also been shown to regulate the proliferation and osteogenic differentiation of rat bone marrow stromal cells (rBMSCs). However, the detailed molecular mechanism of icariin has remained largely unknown. Besides, no investigation has focused on the relevance of icariin in the regulation of rat adipose-derived stem cells (rASCs) proliferation and osteogenic differentiation. In the present study, we detected that icariin promotes proliferation and osteogenic differentiation of rASCs in a concentration range from 10-8M to 10-6M, with 10-7M to be the optimal concentration. We found that 10-7M icariin significantly increased active RhoA protein expression and ROCK substrate molecule p-MYPT1 expression in rASCs. C3 (the RhoA inhibitor) treatment abrogated the increased proliferation and osteogenic differentiation of rASCs induced by icariin. Interestingly, we also found that C3 abrogated the activation of TAZ induced by icariin. Depletion of TAZ by siRNA transfection significantly blocked icariin promoted proliferation and osteogenic differentiation of rASCs. However, icariin induced active RhoA protein expression was not affected by TAZ specific siRNA transfection, suggesting that RhoA lies upstream of TAZ. Taken together, our data indicate that icariin promotes proliferation and osteogenic differentiation of rASCs by activating the RhoA-TAZ signaling pathway.

Strategic and rare elements in Cretaceous-Cenozoic cobalt-rich ferromanganese crusts from seamounts in the Canary Island Seamount Province (northeastern tropical Atlantic)

Thick ferromanganese (Fe-Mn) crusts from four Cretaceous seamounts (The Paps, Tropic, Echo and Drago) at the southern Canary Island Seamount Province (CISP) in the northeastern tropical Atlantic were recovered along the flanks and summits from 1700 to 3000m water depths. CISP is composed of >100 seamounts and submarine hills, is likely the oldest hotspot track in the Atlantic Ocean, and is the most long-lived of known hotspots globally. The Fe-Mn crusts grow on basalt-sedimentary rock substrates below the northeastern tropical Atlantic core of the oxygen minimum zone (OMZ) with a maximum thickness of 250mm at a water depth of 2400m. The mineralogical and chemical composition of these Fe-Mn crusts indicate a hydrogenetic origin. The main Mn minerals are vernadite with minor interlayered todorokite and asbolane-buserite. Fe oxides are essentially ferroxyhyte and goethite. The Fe-Mn crusts show high average contents in Fe (23.5wt%), Mn (16.1wt%), and trace elements like Co (4700μg/g), Ni (2800μg/g), V (2400μg/g) and Pb (1600μg/g). Rare earth elements plus yttrium (REY) averages 2800μg/g with high proportions of Ce (1600μg/g). Total platinum group elements (PGEs) average 230ng/g, with average Pt of 182ng/g. Two main types of growth layers form the crusts: 1) a dense laminae of oxides with high contents in Mn, Co and Ni associated with vernadite and Cu, Ni, and Zn associated with todorokite; 2) botryoidal layers with high contents in Fe, Ti, V and REY associated with goethite. The Fe-Mn crusts from the CISP region show higher contents in Fe, V, Pb and REY but lower Mn, Co, Ni and PGEs contents than Pacific or Indian ocean seamount crusts. The oldest maximum age of initiation of crust growth was at 76Ma (Campanian, Late Cretaceous). Using a combination of high resolution Co-chronometer and geochemical data along an Electron Probe Micro Analysis (EPMA) transect, four stages in morphology, chemical contents and growth rates can be differentiated in the the Cenozoic crusts since 28Ma, which we interpret as due to changes in the ventilation of the North Atlantic OMZ and to the increase of Saharian dust inputs. An earliest growth period, characterized by similar contents of Fe and Mn in the interval 27.8–24.45Ma (late Oligocene-early Miocene) reflects slow precipitation related to a thick OMZ. An intermediate laminated zone with higher contents of Fe, Si and P, high growth rates reaching 4.5mm/Ma, and precipitation of Fe-Mn oxides during the interval 24.5–16Ma is related to periods of ventilation of the OMZ by intrusion of deep upwelling currents. Significant increase in Fe contents at ca. 16Ma correlates with the onset of incursions of Northern Component Waters into the North Atlantic. Finally, since 12Ma, the very low growth rates (<0.5mm/Ma) of the crust are related to a thick North Atlantic OMZ, an increase in Sahara dust input and a stable thermohaline circulation.

A Unique Collection of Palaeolithic Painted Portable Art: Characterization of Red and Yellow Pigments from the Parpalló Cave (Spain).

In this work we analyze the pigments used in the decoration of red and yellow motifs present in the portable art of the Parpalló Cave (Gandía, Spain), one of the most important Palaeolithic sites in the Spanish Mediterranean region. Energy dispersive X-ray fluorescence spectrometry (EDXRF) and spectrophotometry in the visible region (CIEL*a*b*color coordinates and spectral reflectance curves) were used to perform in situ fast analyses of the red and yellow motifs with portable equipment and to characterize their elemental composition and their colorimetric perception, respectively. According to the elemental composition, the intensity of the fluorescence iron signals in red and yellow motifs are higher than average values in the rock substrates. As expected, red motifs possess high values of the chromatic coordinate a* and yellow motifs possess high values of b*. This characterization was complemented with FT-IR analyses of microsamples detached from the red and yellow colored zones of a small set of plaquettes. Our results show that the artists used red and yellow pigments in the decoration likely derived from natural iron oxides as hematite and goethite.

Niche Filtering of Bacteria in Soil and Rock Habitats of the Colorado Plateau Desert, Utah, USA

A common feature of microbial colonization in deserts is biological soil crusts (BSCs), and these comprise a complex community dominated by Cyanobacteria. Rock substrates, particularly sandstone, are also colonized by microbial communities. These are separated by bare sandy soil that also supports microbial colonization. Here we report a high-throughput sequencing study of BSC and cryptoendolith plus adjacent bare soil communities in the Colorado Plateau Desert, Utah, USA. Bare soils supported a community with low levels of recoverable DNA and high evenness, whilst BSC yielded relatively high recoverable DNA, and reduced evenness compared to bare soil due to specialized crust taxa. The cryptoendolithic community displayed the greatest evenness but the lowest diversity, reflecting the highly specialized nature of these communities. A strong substrate-dependent pattern of community assembly was observed, and in particular cyanobacterial taxa were distinct. Soils were virtually devoid of photoautotrophic signatures, BSC was dominated by a closely related group of Microcoleus/Phormidium taxa, whilst cryptoendolithic colonization in sandstone supported almost exclusively a single genus, Chroococcidiopsis. We interpret this as strong evidence for niche filtering of taxa in communities. Local inter-niche recruitment of photoautotrophs may therefore be limited and so communities likely depend significantly on cyanobacterial recruitment from distant sources of similar substrate. We discuss the implication of this finding in terms of conservation and management of desert microbiota.

Complementary influences of co-occurring physical ecosystem engineers on species richness: insights from a Patagonian rocky shore

Structural modification of the environment by physical ecosystem engineers often allows for the occurrence of species that are not able to establish in unengineered habitats, thus leading to increased species richness at the landscape-level (i.e., areas encompassing engineered and unengineered habitats). Unlike previous studies that focused on the contribution of a single engineering species to landscape-level species richness, this study evaluates whether co-occurring engineers—i.e., intertidal mussels (primarily Perumytilus purpuratus) and rock boring bivalves (Lithophaga patagonica)—contribute to landscape-level species richness in a similar or complementary way. Our results show that both mussel and L. patagonica patches harbor a substantial number of invertebrate species in addition to those occurring in the unenegineered rock substrate. However, the distinctive habitat patches created by each engineer add exclusive subsets of species to the study area, which implies that mussel and L. patagonica patches contribute complementarily to overall species richness in our intertidal landscape. Here we postulate that complementary engineering effects on landscape-level species richness will occur when the engineered patches structurally differ from each other and, thus, vary in their relative ability to modulate two or more abiotic conditions and/or resources that prevent species establishment in the unengineered state. In spite of its inherently small spatial scale (500 m), our study highlights the potential for complementary engineering impacts at the larger scales that are usually implied in biodiversity conservation and management (tens to hundreds of kilometers) and outlines a simple conceptual basis and approach to address them.

A simple theoretical approach to the thermal expansion mechanism of salt weathering

The traditional plate theory in solid mechanics is used to estimate the thermal stress caused by a superficial salt layer on a rock substrate. This preliminary investigation theoretically demonstrates that the thermal expansion of superficial salt layers is difficult to result in rock breakdown during the process of salt weathering.

A selective medium for recovery and enumeration of endolithic bacteria

The study of lithic microbial communities, inhabiting rock substrates has been gathering momentum due to a growing attention of their wide importance as model systems in ecological studies and for their community structure. It is generally accepted that the success of cultivation-based technique is primarily based on suitable culture medium for isolation. The media available for enumeration and recovery of endolithic bacteria are mainly specific to particular type of rock which may not be suitable to isolate endolithic bacterial community from diverse lithobiontic niches. In this study, a new unoptimized medium was formulated, designated LM10 (unoptimized) for enumeration and recovery of endolithic bacteria by addition and/or omission of media components to the basal medium R2G, which was selected after experimental evaluation of five different existing media. The endolithic bacterial count in LM10 medium (unoptimized) was significantly higher than the R2G medium (t=−12.57, p<0.0001). The culture and nutritional parameters associated with unoptimized LM10 medium were optimized using statistical approach to maximize the recovery and enumeration of endolithic bacteria. The first phase of the study comprised of a Plackett-Burman (PB) design experiment conducted to screen thirteen medium components and two culture parameters as variables with effect on bacterial enumeration and recovery. Out of these, Yeast extract, Casein hydrolysate, Glucose, Starch and Sodium thiosulphate were found to be significantly affecting the bacterial count (p<0.05) based on PB design. On keeping rest of the media components and culture conditions at fixed value as per the PB design analyses (p>0.05 and coefficients), further optimization was carried out for significant factors using Box-Behnken design (BBD) of response surface methodology (RSM). Optimized media components obtained by BBD were Yeast extract, Casein hydrolysate, Glucose and Starch in 0.05g/l each and Sodium thiosulphate in 0.047g/l concentrations. The composition of optimized LM10 medium formulated (per litre) is 0.05g Yeast extract, 0.05g Casein hydrolysate, 0.05g Glucose, 0.05g Starch, 0.01g K2HPO4, 0.02g Sodium pyruvate, 0.2g MgSO4, 0.001g FeSO4·7H2O, 0.285g NH4Cl, 0.039g CaCl2·2H2O, 0.047g Na2S2O3·5H2O, 0.002g NaHCO3 and 11g Gellan gum (pH=7.4). Validation of optimized LM10 medium using nine different rock samples from Meghalaya clearly indicated that optimized LM10 medium was better suited for higher recovery and enumeration of endolithic bacteria under both aerobic and anaerobic conditions.

Contribution to the lichen biota of the Stawy Milickie nature reserve and its adjacent area (Lower Silesia, southwestern Poland)

The paper presents the results of lichenological investigations conducted in the eastern part of the Stawy Milickie nature reserve and its buffer zone (Barycz Valley, southwestern Poland). The study area is a famous waterfowl refuge, consisting of several fishpond complexes, together with adjacent forests, meadows, and villages. In total 72 lichen taxa were recorded, growing on bark and branches of trees and shrubs, stumps, wood, soil, and anthropogenic rock substrates (mortar, concrete, bricks, etc.). Six species, namely &lt;em&gt;Evernia prunastri&lt;/em&gt;, &lt;em&gt;Flavoparmelia caperata&lt;/em&gt;, &lt;em&gt;Hypogymnia tubulosa&lt;/em&gt;, &lt;em&gt;Parmelina tiliacea&lt;/em&gt;, &lt;em&gt;Physconia distorta&lt;/em&gt;, and &lt;em&gt;Pleurosticta acetabulum&lt;/em&gt;, are threatened in Poland. As represented by single young thalli, they indicate the recent improvement of environmental conditions. The lichen biota of the study area is typical for the lowland regions of western and southwestern Poland.

The generation and mineral associations of rock assemblages at mud volcanoes: Southeastern Siberia

We consider the main features in the formation of rock assemblages in the southern Siberian Mesozoic–Cenozoic mud volcanism area that the present writers identified. The related mineral associations and mechanism of generation were found. We identified fluid dynamic regimes of mud volcanoes with different mechanisms of mineral generation, viz., root (chamber) structures of fluid generation, as well as the channels for the transmission of the fluid–rock substratum and of hydrothermal fluids.