Open Rock Research Articles

Local and global stressors as major drivers of the drastic regression of brown macroalgae forests in an oceanic island

Similar to other coastal regions worldwide, forests created by brown macroalgae have severely declined in recent decades across the Macaronesian oceanic archipelagos (northeastern Atlantic), eroding the provision of ecosystem services. However, the putative effects of natural and anthropogenic stressors (both local and global) on such declines across spatial and temporal scales remain unresolved. Our research endeavored to investigate the connection between local and global stressors and the distribution and extent of the brown macroalgae Gongolaria abies-marina in the rocky intertidal and adjacent subtidal zones of Gran Canaria over the past four decades. We also quantified the presence of populations at small scales, according to local micro-habitat topography (“open rock” versus “refuge”). Through herbarium records, we additionally analyzed the historical variation in the thallus size of the species. Finally, we experimentally assessed the thermotolerance of embryonic stages to warming. The main environmental drivers explaining the regression of G.abies-marina were the increasing number of marine heatwaves, while the number of local human impacts (quantified through the HAPI index) also accounted for further regression in the extent of marine forests. Warming experimentally reduced the survival and size of macroalgal embryos. A progressive miniaturization of the species, currently restricted to micro-habitat refuges as a survival strategy, seems likely to be the final stage in the progressive disappearance of this macroalgae from the island’s rocky shores.

To the selection of technology parameters for the use of renewable energy sources on man-made disturbed lands

Renewable energy sources (RES) have become widely used in many developed countries of the world. In the article, the use of RES is considered using the example of wind energy installations (WEI). For industrial scale volumes of electricity produced, wind energy installations of large capacities and designs are used. To choose a rational design of windmills, a classification of windmills of existing designs is provided. Known foreign types of efficient wind generators are considered. Most often, wind energy installations are used in places with a strong wind flow. Wind energy installations with a horizontal axis of rotation are usually used in these areas. For example, information is given on one of the largest wind farms in Ukraine - the Botiivskyi wind farm, which consists of 65 wind energy installations with a horizontal axis of rotation. The practice of using windmills, despite the great benefits of their use, has significant drawbacks. This problem consists in deriving large plots of land for use and having an impact on the surrounding environment. This, in turn, leads to negative consequences for the ecology of these regions. In connection with this, there was a need to use wind energy installations on land plots that have been decommissioned in the conditions of Kryvbas. These include sparsely populated regions, wastelands, and decommissioned plots of land on which the facilities of mining enterprises are located. It has been proven that the placement of WEI with a vertical axis of rotation of medium power on overburden dumps has its own characteristics. For most of the territory of Ukraine, the average wind speed is 3-5 m/s, so the use of wind turbines with a vertical axis of rotation is more appropriate. The starting speed of such wind energy installation is 0.5 m/s, and at a wind speed of 3 m/s, wind energy installations can reach their nominal power. The paper analyzes the possibility of using wind energy installations on man-made disturbed lands, namely on open rock dumps, and recommends their design features. The calculation of the wind energy potential for vertical and horizontal wind energy installations in the conditions of the city of Kryvyi Rih was made. A comparison of the use of vertical and horizontal wind energy installations was made. The effectiveness of the use of wind energy installations with a vertical axis of rotation in the conditions of Kryvbas is shown.

Influence of COVID-19 on the emergence of stone-tool use behavior in a population of common long-tailed macaques (Macaca fascicularis fascicularis) in Thailand.

Stone tool use is a rare behavior across nonhuman primates. Here we report the first population of common long-tailed macaques (Macaca fascicularis fascicularis) who customarily used stone tools to open rock oysters (Saccostrea forskali) on a small island along the Thai Gulf in Koh Ped (KPE), eastern Thailand. We observed this population several times during the past 10 years, but no stone-tool use behavior was observed until our survey during the coronavirus disease 2019 (COVID-19) pandemic in July 2022. KPE is located in Pattaya City, a hotspot for tourism in Thailand. Tourists in this area frequently provided large amounts of food for the monkeys on KPE. During the COVID-19 curfew, however, tourists were not allowed to access the island, and monkeys began to face food scarcity. During this time, we observed stone-tool use behavior for the first time on KPE. Based on our observations, the first tool manipulation was similar to stone throwing (a known precursor of stone tool use). From our observations in March 2023, we found 17 subadult/adult animals performing the behavior, 15 of 17 were males and mostly solitary while performing the behavior. The M. f. fascicularis subspecies was confirmed by distribution, morphological characteristics, and mtDNA and SRY gene sequences. Taken together, we proposed that the stone tool use behavior in the KPE common long-tailed macaques emerged due to the COVID-19 food scarcity. Since traveling is no longer restricted many tourists have started coming back to the island, and there is a high risk for this stone tool-use behavior to disappear within this population of long-tailed macaques.

Local temperature near native vascular plants in the Argentine Islands–Kyiv Peninsula region, Antarctic Peninsula: annual variability and approximation using standard meteorological measurements

We describe the main features of LT variability that influence native vascular plants in the Antarctic and examine the relationship between the temperature regime at the micro-level and meteorological conditions at the macro-level. We used a period of over a year, during which 37 specialized mini-loggers recorded LT near vascular plants in the Argentine Islands–Kyiv Peninsula region of the Antarctic Peninsula. Rather than measuring standard air or soil temperature, these loggers detect the temperature near the ground, in the microhabitats that harbour vascular plants. On a daily scale, LT correlates with standard (2-m) air temperature, with the values higher at rock slopes than at rock terraces and ledges. A moderate correlation was found with wind and radiation parameters. Seasonality accounted for 75–93% of total LT variability, with better results on open rock terraces compared to protected areas and clefts. LT day-to-day variability during the cold season is mostly responsible for differences in R2 of the annual cycle. We estimated daily mean LT using regression dependencies from 2-m air temperature and wind speed measured at a nearby meteorological station. R2 for these statistical models varies from 0.46 to 0.68. However, they underestimate the observed LT. LT measured on rock slopes showed better modelling results with air temperature, whereas wind speed was a better predictor on rock ledges. This study contributes to our understanding of the micro-scale temperature regime that influences native vascular plants and provides a method for its rough approximation using standard meteorological parameters.

Studies on Microhabitat Diversity of Sadetin Rodaga Basaltic Rock Outcrop, Nasik District (Maharashtra), India

The present investigation was carried out to study distribution of flowering plants in various microhabitats present on Sadetin Rodaga rock outcrop/plateau from Northern Western Ghats. This plateau was Basaltic and most of area is covered with black rock with thin as well as thick layer of black soil. Floristic survey revealed the presence of 241 species belonging to69 families. All species distributed in a ten specific microhabitats (Open rock surfaces, Isolated rocks, Rock crevices, Soil covered places, Ephemeral flush vegetation, Edges of plateau, Soil rich area, Soil-filled depressions, Exposed rock surfaces, Boulders etc.). Phenology pattern of flowering plants also recorded. Voucher specimens were collected and herbariums were prepared.

Offshore wind farms affect the spatial distribution pattern of plaice Pleuronectes platessa at both the turbine and wind farm scale

Abstract We investigated how the distribution of plaice Pleuronectes platessa, a typical soft-sediment fish species, has been affected by the introduction of hard substrate [turbines and scour protection layer (SPL)] at both turbine and wind farm scale in two Belgian offshore wind farms (OWFs). Diving transects (40 m) at 11 monopiles revealed four times higher plaice abundances on the sandy patches of the SPL (average radius 16.5 m) compared to the surrounding sand. We suggest that the configuration of the SPL, i.e. an open rock field, offering increased food and shelter opportunities, with sandy patches in between, facilitating the natural burrowing behaviour of plaice, forms the basis for the increased plaice abundances at the turbine scale. At the wind farm scale, beam trawl catches in between the turbines and in reference zones revealed significantly increased plaice abundances in one OWF, which suggests that wind farms can act as refuge areas for plaice, at least under specific conditions. Differences in environmental conditions, turbine foundation type, and surrounding fishing pressure may explain the equivocal findings between both OWFs, whereas low statistical power could have hampered the detection of general refuge effects. Next to the integration of different spatial scales (turbine/wind farm) within one study, longer-term monitoring and including extra life history parameters (e.g. length and sex ratio) might enhance the detectability of potential refuge effects.

Temperature cycles beneath, and adjacent to, intertidal boulders and associated differences in biotic composition

The only previous study on the macrobiota of South African boulder shores showed this assemblage to be more diverse than on nearby rocky platforms, but the drivers of that difference remain unresolved. We recorded water and air temperatures under intertidal boulders and on adjacent exposed rocky platforms, at both the upper- and lower-shore level, at Kommetjie, South Africa, over 2-week tidal cycles, repeating this during summer and winter. The macrobiota in each location was also sampled during diurnal low tides. The most-extreme temperatures, and greatest ranges, occurred during summer on upper-shore open rock (13.9–37.7 °C, range difference of 23.8 °C), while under upper-shore boulders the maximum temperature was lower at 28.9 °C and the range spanned only 15.5 °C. In winter, maximum temperatures and ranges were lower at all locations. Maximum temperatures did not coincide with spring tides, but occurred several days later, when low tides happened during the heat of the day. Closer analysis of daily fluctuations revealed influence of weather on temperatures attained and showed that durations of elevated temperatures were much shorter in the lower shore. The upper shore exhibited low biodiversity, supporting only 9 species, with 8 found only under boulders during diurnal low tide; the lower shore was more diverse, with 11 species on open rock and 29 under boulders. Biomass and abundance were also higher under boulders at both levels, especially on the upper shore. More-benign under-boulder conditions thus facilitate more abundant and diverse biota sheltering there than occurs on adjacent exposed rocks, particularly on the upper shore.

Why Are Barnacles Common on Intertidal Rocks but Rare in Rock Pools? Effect of Water Temperature, Salinity, and Continuous Submergence on Barnacle Survival in Indian Ocean Rock Pools

Barnacles are less common in rock pools of the rocky intertidal zone than on open rock surfaces adjacent to those pools. Rock pools on the Andaman coastlines of Thailand showed diurnal variations in water temperature, salinity, pH, and dissolved oxygen level, peaking in the afternoon. Multivariate analysis showed that water temperature and salinity (not pH and dissolved oxygen) can affect barnacle abundance in rock pools. The present study tests the hypothesis that a lack of recruitment or pool environmental conditions (continuous submergence, water temperature, and salinity extremes) affect the abundance of barnacles (Chthamalus malayensis and Amphibalanus amphitrite) in rock pools. During the recruitment season, recruits were found in a number of rock pools, but at significantly lower abundances than those in adjacent open rock surfaces. In a laboratory experiment, C. malayensis and A. amphitrite that were continuously submerged had a lower survival (80%) than the controls (simulated tide conditions; >90% survivals). Under different water temperature and salinities treatments, barnacles had low survival (<50%) in the low salinity (0‰) and high temperature treatment (40°C). The present study suggests that C. malayensis and A. amphitrite can recruit into rock pools, and the interplay of continuous submergence, high water temperature and low salinity in rock pools can bring about mortality in barnacles.

FUNGI (BASIDIOMYCOTA) ON ISLANDS OF LAKE ONEGO (REPUBLIC OF KARELIA)

Records from islands in Lake Onego list 145 species of aphyllophoroid fungi, including Gloeophyllum protractum, Junghuhnia collabens, J. pseudozilingiana, Polyporus badius, Rigidoporus crocatus, and Tyromyces fissilis, which are red-listed in the Republic of Karelia (2020). Data are reported on the distribution of 4 species new for the Karelia onegensis province. Specimens of all the new records are kept in the mycological herbaria of the Karelian Research Centre (PTZ). A majority of aphyllophoroid fungi on islands in Lake Onego were found on deciduous trees (94 species), and 53 species were recorded from coniferous trees. The greatest numbers of fungal species were found on rowan (39), aspen (38), pine (32), spruce (25), willow (25), and birch (21). Locations of 18 indicator and specialized species of old-growth forests were found on the islands. The species richness of aphyllophoroid fungi on each island depended on a set of factors – tree species composition and presence of deadwood in different stages of decay, proportion of the forest cover (open rock), different types of habitats, and the degree of anthropogenic disturbance. The island size was not significant. Brief information about agaricoid fungi is also provided.

Rhododendron smokianum, a New Species from the Great Smoky Mountains

Abstract—Species delimitation in Rhododendron subsect. Caroliniana (Ericaceae) has been disputed in the past with one or three species accepted. Here we report a fourth species, R. smokianum, a narrow endemic from the Great Smoky Mountains (Tennessee/North Carolina, USA). It is characterized by short-tubed corollas and small, compact growth. We support our conclusion by phylogenetic analyses of ITS and plastid trnL-F sequence data. The new species is a specialist of open mafic rock slopes and maintains morphological and phenological differences to the related species even in cultivation.

Impact resistance of limpet shells: a study of local adaptations

Limpets are molluscs which have a conical shell that is well adapted to resist fracture by impact from projectiles such as rocks during storms. We hypothesised that the impact strength of the shell varies depending where the animal is located, reflecting the relative risk of high-energy impact. We quantified shell impact strength for the species Patella vulgata using a normalised energy. Limpets located in exposed places on open rock surfaces were found to be more than twice as strong as those living constantly underwater (7.34 MJ/m4.6 v 3.48 MJ/m4.6). This difference was discussed using a theoretical model based on the physics of projectiles moving through fluids. Limpets located in rocky crevices had an intermediate impact strength (5.43 MJ/m4.6), attributed to the reduced probability of impact in these locations. Differences in impact strength were found to be linked to two geometric parameters: apex thickness and the ratio of apex height to rim diameter. Combining the present results with data from previous work, we developed a theoretical model which was able to predict impact strength accurately as a function of rim diameter, apex height and apex thickness. These results demonstrate the considerable plasticity of form, which this species is capable of, helping to explain why it is so abundant. The findings may be valuable in the biomimetic development of lightweight impact resistant structures.

Initial Effects of Wildfire on Freshwater Turtle Nesting Habitat

ABSTRACTNatural wildfire regimes are important for ecosystem succession but can have negative ecological effects depending on fire characteristics. A portion of a granite rock barrens landscape that extends along the eastern shoreline of Georgian Bay, Lake Huron to eastern Ontario, Canada, burned in 2018 during a wildfire that affected >11,000 ha. This landscape is a biodiversity hotspot providing habitat for many species at risk where freshwater turtles nest in soil deposits in cracks and crevices in the bedrock dominated by moss (Polytrichum spp.) and lichen (Cladonia spp.) cover. To assess the initial effect of wildfire on freshwater turtle nesting habitat, we measured soil depths and estimated moss, lichen, and vascular plant cover at 2 morphology types (crevice, flat) in burned and unburned areas of the landscape. The probability that burned flat plots supported soil was near zero; the burned flat plots had 98% less soil volume compared to unburned flat plots. Although crevices were more resistant to soil loss, burned crevices still had a 15% lower probability of having soil and 35% less soil volume compared to unburned crevice plots. We estimated nest site availability by calculating the number of locations with shallow (5–10 cm), intermediate (10–20 cm), and deep (>20 cm) soils required for a small (5 cm × 5 cm) or medium (10 cm × 10 cm) nest chamber. Overall, the burned open rock barrens had 71–73% fewer sites with suitable soil depth and volume for a nest chamber of either size. Furthermore, burned plots had almost no lichen and moss cover but were dominated by bare soil, forbs, and jack pine (Pinus banksiana) seedlings. Although the loss of tree cover in previously forested areas may increase nest site availability for freshwater turtles in newly open areas, we suggest that organic soil combustion and soil erosion may require restoration activities in the post‐fire landscape to support successful nesting of at‐risk turtles. © 2020 The Wildlife Society.

Geomicrobial Investigations of Colored Outer Coatings from an Ethiopian Rock Art Gallery

The open rock shelter of Yabelo in Ethiopia hosts diverse Holocene paintings of great cultural importance. The paintings are characterized by the presence of different mineral coatings, whose features have not been studied yet. Our goal was to understand whether different rock samples from the Yabelo paintings collected in close proximity may reveal coatings with different minerology and biology. Thus, elemental analyses combined with microscopic and molecular investigations were performed on two coatings, one whitish (sample 1) and one reddish (sample 2). Although both samples were dominated by heterotrophic bacteria, the two coatings showed distinct mineralogical and microbiological characteristics. Sample 1 contained higher amounts of Ca and P than sample 2, which was likely related to the presence of organic matter. Sample 1 hosted bacterial genera that are potentially involved in biomineralization processes, metal redox cycles and metal resistance. In contrast, sample 2 showed mainly pathogenic and commensal bacteria that are characteristic of animal and human microbiota, and other microorganisms that are involved in nitrogen and metal biogeochemical cycles. Overall, our results indicated that the bacterial communities were particular to the coating mineralogy, suggesting a potential role of the biological components in the crust genesis.

Capillary pressure and relative permeability estimation for low salinity waterflooding processes using pore network models

In this work, the effect of low salinity waterflooding (LSWF) on capillary pressure and relative permeability is studied at pore scale. For this purpose, a pore-scale model implemented on OpenPNM is developed to describe fluid flow, salinity transport and wettability change in a pore network. The effect is studied by considering high salinity waterflooding followed by low salinity waterflooding. The system wettability change is introduced as modifications of the local contact angle that are induced by the water salinity reduction. These modifications are evaluated by calculating the contact angle change in each pore and throat of the network, and then integrating it. From this analysis, a methodology has been developed to study the LSWF impact on capillary pressure and relative permeability. This methodology has been successfully applied to two pore network cases available in an open rock data base; one network correspond to a sandstone and the other to a carbonate sample. The methodology developed here can be seen as a tool to complement laboratory tests needed to determine the efficiency of LSWF processes.

New developments in the radiocarbon dating of mud wasp nests

Abstract This paper reports on the development of radiocarbon dating of mud wasp nests to provide age estimates for rock art and other anthropogenic modifications to the surfaces of open rock shelters. Over 150 rock shelters in the remote Kimberley region of Western Australia were visited in five field seasons. Mud wasp nest samples were collected from 108 sites. Thirty newly constructed wasp nests were collected to understand their initial composition and to determine the major sources of carbon. Charcoal-rich fractions extracted from 9 modern nests were radiocarbon dated and, whilst most were of zero age, some were found to be up to 1000 years old with the mean age being 255 years. Of the old wasp nest samples, 120 were utilised in the experiments reported here. A variety of different physical and chemical pretreatment methods were explored but small sample sizes and low carbon concentrations limit the range of techniques that can be used in practice. The radiocarbon ages measured on the 75 nest samples that contained sufficient carbon for analysis ranged from Modern to just over 20 cal ka BP. Half of these nests were older than 8 cal ka BP and 20% were older than 11 cal ka BP. Even allowing for the inherent uncertainties due to any inbuilt carbon age, the method is capable of producing useful age estimates for rock art and other features of archaeological interest, in relatively open rock shelters.

On the timing and duration of foraging inOnchidella celtica

Time-lapse photography was used to study the timing and duration of foraging activity of a population of the pulmonate gastropodOnchidella celticaon an exposed rocky shore in Cornwall, UK. The pulmonates spent most of their time in their home crevice, emerging onto open rock only during some ebb tides to forage for food and find a mate. Total duration and speed of foraging was highly variable and did not generally conform to a triphasic pattern. The number foraging was also highly variable and was not correlated significantly with the spring/neap tide cycle or weather (air temperature above 12°C, air pressure, solar radiation, precipitation, relative humidity and wind speed). There was a significant negative correlation between foraging and surf height. Although the pulmonates foraged during all hours of the day/night cycle, foraging activity tended to be highest during the afternoon and evening.

Numerical Modelling of Steep Slopes in Open Rock Quarries

ABSTRACT The key question regarding steep rock slopes along rock quarries is their stability because a rock slope failure can have critical results. In this study, the aim is to investigate the areas with potential risk for jointed karstic limestones in a rock quarry. First, to determine rock mass properties, scan-line surveys were performed, and the major orientations of discontinuities were analyzed using stereographic projection. Then, the physico-mechanical properties of the slope-forming rock were determined in the laboratory, and geomechanical properties of the rock mass were determined using an empirical failure criterion. Finally, the quarry slope stability was assessed in accordance with numerical modelling. According to the results obtained, the numerical modelling of steep rock slopes can be efficiently evaluated by using finite element method. Beside this, the presence of joints intersecting the main discontinuity sets, the filling materials of discontinuities resulting from weathering of limestone and surface deposits, surcharge load due to mine waste dumped on the slopes and excavation blasting during construction of quarry area play a key role when modelling the steep rock slopes by using finite element method.

The effect of compression load and rock bridge geometry on the shear mechanism of weak plane

Rock bridges in rock masses would increase the bearing capacity of Non-persistent discontinuities. In this paper the effect of ratio of rock bridge surface to joint surface, rock bridge shape and normal load on failure behaviour of intermittent rock joint were investigated. A total of 42 various models with dimensions of 15 cm × 15 cm × 15 cm of plaster specimens were fabricated simulating the open joints possessing rock bridge. The introduced rock bridges have various continuities in shear surface. The area of the rock bridge was 45 cm2 and 90 cm2 out of the total fixed area of 225 cm2 respectively. The fabricated specimens were subjected to shear tests under normal loads of 0.5 MPa, 2 MPa and 4 MPa in order to investigate the shear mechanism of rock bridge. The results indicated that the failure pattern and the failure mechanism were affected by two parameters; i.e., the ratio of joint surface to rock bridge surface and normal load. So that increasing in joint area in front of the rock bridge changes the shear failure mode to tensile failure mode. Also the tensile failure change to shear failure by increasing the normal load.

Recovery of Low Permeability Reservoirs Considering Well Shut-Ins and Surfactant Additivities

To investigate the mechanism whereby well shut-ins and surfactant additivities can increase hydrocarbon output after hydraulic fracturing, in this paper, we simulated well shut-ins with one end open (OEO) rock samples and performed a serious of imbibition experiments with different surfactant additivities based on contact angle (CA) and interfacial tension (IFT) measurements. Scanning electron microscope (SEM) and nuclear magnetic resonance (NMR) methods were also been adopted in the detection before and after shut-ins. The results demonstrated that cationic surfactants result in better improving oil recovery (IOR) performance due to their high wettability alteration ability on vertical fracture faces, while different kinds of surfactants have a similar ability in lowering IFT. As for shut-ins duration, the NMR transverse relaxation time (T2) spectrum move towards the left side, indicating that aqueous phases migrate to smaller pores spaces and deeper distances. Aqueous migration during the shut-ins period can remove near-fracture trapped water, while surfactant additivities can accelerate and enhance this process, and these two points are the most direct reasons for the observed hydrocarbon output increases.

Petroglyphs from Northeast China: New Sites and Interpretations

This article is based on the results of fi eld studies in Northeast China (Dongbei) in 2012–2014. We describe 18 petroglyphic sites, most of which were hitherto unknown or little known to Russian, European, or Chinese scholars. All petroglyphs are located on open rock surfaces, vertical or horizontal. Two techniques were used—painting and carving. The most common paint was ocher of different shades: from tawny or maroon to bright orange; in rare cases, black paint was used. The distribution areas of the two techniques largely coincide with those of ethno-cultural groups occupying various parts of the region: paintings were distributed mostly in areas of mountain taiga whereas most carvings were found in the mountain steppe. Figurative images and abstract signs are discussed in detail. Most figurative images are either anthropomorphic or zoomorphic. Abstract signs include dots, circles, crosses and other geometric figures. Petroglyphs of Dongbei show numerous parallels with those of Mongolia, Trans-Baikal, Korea, and the Amur region.