Stone Runs Research Articles

Assessing the Touristic Value of the Stone Run at Mt. Okryon in the Korean Peninsula

Assessing the Touristic Value of the Stone Run at Mt. Okryon in the Korean Peninsula

Forage plants for the northern pika (<i>Ochotona hyperborea</i> Pallas) in the Chuvansky Range System (South Chukotka)

The northern pika (Ochotona hyperborea Pallas) is a small herbivorous animal from the Ochtonidae family, widely distributed in the mountains of Northeast Asia. Despite its small size, the northern pika plays a noticeable role in the transformation of organic substances of biocenoses. An essential feature of these mammals is the procurement of plant food for the winter period. The food ration of the animals is very diverse and depends on the structure of the surrounding vegetation. It includes aerial parts of shrubs, sub‑shrubs, herbaceous plants, ferns, Equisetum species, rarely trees, bushy lichens, fungi and very rarely mosses. According to our analysis of the literature data, more than 220 species of vascular plants are included in the diet of the northern pika in Northeast Asia. During a survey of the northern spurs of the Chuvansky Range in the basin of the Ozernoe Gorlo river (Anadyr river basin), 14 species of vascular plants, 8 species of bushy lichens and 1 species of moss were identified in winter stocks of the northern pika on 2 terrain areas differing in landscape and vegetation structure. Salix pulchra, S. berberifolia subsp. tschuktschorum, Chamaenerion latifolium, Vaccinium uliginosum subsp. microphyllum, Empetrum nigrum, Ledum palustre subsp. Decumbens are of great importance as the preferred food of northern pika in this territory. In addition, the Dryopteris fragrans fern and more rarely Betula nana, are harvested quite sustainably in one of the sections of a stone scree (stone run) surrounded by a Pinus pumila community. The role of bushy lichens and mosses in the nutrition of the northern pika needs to be clarified.

Cryogenic Soils in the Chara River Valley (Transbaikalia)

The object of the study are the cryogenic soils located within the Chara valley. We attributed soils in a post-pyrogenic sparse larch forest on the terrace of the Chara River, to the type of gleyzems (Gleysols), subtypes - permafrost cryogenically ferruginized cryoturbated and permafrost cryogenically ferruginized post-pyrogenic. The field diagnostics of these two soils is ambiguous, since the soil profiles contain some morphological features that make it possible to identify them as podburs (Entic Podzols): a bright red color of the BF horizon, a sandy loam texture, containing less than 19% of clay particles (" 10 µm). Field diagnostics, together with laboratory studies, indicate that the soils in the section on the stone run at the top of the Udokan Ridge belongs to peat-lithozem (Histic Leptosols). Chemical analyses have shown that the described soils are acidic with pH ranges from 4.9 to 5.4 and relatively slightly saline, TDS ranges from 8.1 to 18.9 mg/L. The carbonate alkalinity is also relatively low: 2.4–4.8 mmol(-)/100 g of soil. The sections are strongly differentiated by the content of organic carbon. Permafrost peat-lithozem contains from 9.3 to 37.8%, permafrost cryogenically ferruginized post-pyrogenic gleyzem is much less enriched in it, the content here does not exceed 6.8%, usually being around 0.9%.

Identification, characteristics and classification of cryogenic block streams

Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle of repose of coarse sediments. They are usually formed on perennially frozen ground, but can also occur as relict landforms. There are three main active kinds forming today, viz ., Siberian and Tibetan dynamic rock streams and lag block streams. During their formation, the blocks in the active Siberian and Tibetan dynamic block streams move downslope at up to 1 m/a. They are forming today on the Tibetan Plateau and in the more arid parts of south-central Siberia, although the processes involved in the movement are different. In the case of the Tibetan type, individual blocks slide downslope over the substrate in winter on an icy coating in areas of minimal winter precipitation. The Siberian type develops in areas of 15–80 cm of winter snow cover and an MAAT (mean annual air temperature) of ?4 ℃ to ?17 ℃. The movement is due to creep of snow and ice and collapse of the blocks downslope during thawing. Lag block streams are formed by meltwater flowing over the surface of sediment consisting primarily of larger blocks with a limited amount of interstitial sediment. The erosion of the matrix is primarily in the spring in areas of higher winter precipitation on 10°–30° slopes. The blocks remain stationary, but the interstitial sediment is washed out by strong seasonal flows of meltwater or rain to form an alluvial fan. The boulders undergo weathering and become more rounded in the process. Lag block streams can also develop without the presence of permafrost in areas with cold climates or glaciers. Block streams also occur as relict deposits in older deposits under various climatic regimes that are unsuitable for their formation today. An example of relict lag block streams with subangular to subrounded blocks occurs in gullies on the forested mountainsides at Felsen in Germany, and is the original 'felsenmeer'. Similar examples occur near Vitosha Mountain in Bulgaria. The 'stone runs' in the Falkland Islands are examples of the more angular relict lag block streams. In both Tasmania and the Falkland Islands, they mask a more complex history, the underlying soils indicating periods of tropical and temperate soil formation resulting from weathering during and since the Tertiary Period. Block streams have also been reported from beneath cold-based glaciers in Sweden, and below till in Canada, and when exhumed, can continue to develop.

Does a shift in host plants trigger speciation in the Alpine leaf beetle Oreina speciosissima (Coleoptera, Chrysomelidae)?

BackgroundWithin the Coleoptera, the largest order in the animal kingdom, the exclusively herbivorous Chrysomelidae are recognized as one of the most species rich beetle families. The evolutionary processes that have fueled radiation into the more than thirty-five thousand currently recognized leaf beetle species remain partly unresolved. The prominent role of leaf beetles in the insect world, their omnipresence across all terrestrial biomes and their economic importance as common agricultural pest organisms make this family particularly interesting for studying the mechanisms that drive diversification. Here we specifically focus on two ecotypes of the alpine leaf beetle Oreina speciosissima (Scop.), which have been shown to exhibit morphological differences in male genitalia roughly corresponding to the subspecies Oreina speciosissima sensu stricto and Oreina speciosissima troglodytes. In general the two ecotypes segregate along an elevation gradient and by host plants: Oreina speciosissima sensu stricto colonizes high forb vegetation at low altitude and Oreina speciosissima troglodytes is found in stone run vegetation at higher elevations. Both host plants and leaf beetles have a patchy geographical distribution. Through use of gene sequencing and genome fingerprinting (AFLP) we analyzed the genetic structure and habitat use of Oreina speciosissima populations from the Swiss Alps to examine whether the two ecotypes have a genetic basis. By investigating a wide range of altitudes and focusing on the structuring effect of habitat types, we aim to provide answers regarding the factors that drive adaptive radiation in this phytophagous leaf beetle.ResultsWhile little phylogenetic resolution was observed based on the sequencing of four DNA regions, the topology and clustering resulting from AFLP genotyping grouped specimens according to their habitat, mostly defined by plant associations. A few specimens with intermediate morphologies clustered with one of the two ecotypes or formed separate clusters consistent with habitat differences. These results were discussed in an ecological speciation framework.ConclusionsThe question of whether this case of ecological differentiation occurred in sympatry or allopatry remains open. Still, the observed pattern points towards ongoing divergence between the two ecotypes which is likely driven by a recent shift in host plant use.

Stone run (block stream) formation in the Falkland Islands over several cold stages, deduced from cosmogenic isotope (10Be and 26Al) surface exposure dating

AbstractCosmogenic isotope (10Be and 26Al) surface exposure dating has been applied to valley‐axis and hillslope stone runs (relict periglacial block streams) and their source outcrops in the Falkland Islands, South Atlantic. The data indicate that stone runs are considerably older landforms than previously envisaged and afford no evidence that they are a product of the Last Glacial Maximum; the samples range in apparent 10Be age from 42k to 731k yr BP, but some of these are minima. The results indicate that valley‐axis stone runs may be up to 700–800k yr old, have simple exposure histories and are composite landforms that developed over several cold stages. Analyses of some hillslope and outcrop samples also demonstrate simple exposure histories with 10Be ages from 42k to 658k yr BP. In contrast, isotopic ratios from other hillslope and outcrop samples reveal they have had a complex exposure history involving periods of burial or shielding; the samples range in 10Be age from 59k to 569k yr BP and these are regarded as minimum age estimates. Larger stone runs may be older than smaller runs and there is a possibility that stone runs older than 800k yr exist in other parts of the Falklands. The assertion that glaciation in the Falklands was restricted to the highest uplands is supported by the data, and the potential for age determination of other boulder‐strewn and bedrock landforms, using cosmogenic isotope analysis, in order to extend the geochronology of Quaternary events and processes is noted. Copyright © 2008 John Wiley & Sons, Ltd.

Stone runs in the Falkland Islands: Periglacial or tropical?

“Stone runs” is the Falklands vernacular term for openwork boulder accumulations, which include extensive blockstreams like the famous Darwin “stone-river” and associated features such as stone stripes. Since the early 20th century, they have been interpreted as the product of a suite of periglacial processes, including frost-wedging, gelifluction, frost heave, frost-sorting and snowmelt runoff. Following a literature review, the results of recent field investigations of the valley-floor blockstreams of East Falkland are presented. Access to the internal structure of these forms provides evidence for the existence of a three-fold profile, with clear vertical size gradation presenting striking similarities with an inverted weathering profile. Micromorphological analyses, SEM, XRD, thin sections and grain-size analyses lead to the hypothesis of an alternative model of stone run formation. It is suggested that the material forming the stone run profile lato sensu (including the superficial pavement) is not of periglacial origin, but derives directly from the stripping and accumulation downslope of a regolith, possibly Tertiary in age and formed under subtropical or temperate conditions. The valley-floor stone runs should, therefore, be considered as complex polygenetic landforms that may have formed according to a six-stage scenario, including in situ chemical weathering, regolith stripping by mass movements, soil formation, further regolith stripping, downslope accumulation and matrix washing-out (all phases possibly achieved by the Early Quaternary). Periglacial reworking of the stone run material would have operated at a “final” stage, i.e. during Quaternary cold stages, with boulder bioweathering and limonite-staining operating during the temperate intervals including the present one. The suggested antiquity of the Falklands blockstreams is in accordance with Caine's pioneer interpretation of Tasmania blockfields and with recent analyses and cosmogenic datings of blockfields from Scandinavia and North America.

The Influence of Acidic Runoff Episodes on Slimy Sculpin Reproduction in Stone Run

Abstract Much research has been devoted to the effects of acidic runoff episodes on populations of brook trout Salvelinus fontinalis. Less is known about slimy sculpin Cottus cognatus and why their numbers have declined in acidified streams. Adult tolerance of low pH and aluminum (Al) toxicity is similar in these two species. Slimy sculpin spawn in the spring, when high stream flows elevate concentrations of toxic Al and decrease stream pH in acid-sensitive watersheds. We hypothesized that acidic episodes in spring were a source of stress for slimy sculpin and hindered their reproduction. We tested this hypothesis by examining the mortality, behavior, whole-body sodium concentrations, and spawning among slimy sculpin exposed to ambient conditions during the spring spawning period in two Pennsylvania streams, Stone Run (an episodically acidified stream that formerly contained slimy sculpin) and Benner Run (a stream with slimy sculpin that does not experience severe acidic episodes). Our hypothesis was supp...

Episodic flow–duration analysis: a method of assessing toxic exposure of brook trout (Salvelinus fontinalis) to episodic increases in aluminum

Episodic flow–duration curves were developed that summarize stream flow data by considering the duration of sustained flows at or above specified levels. These curves and relationships between dissolved aluminum concentrations and stream flow were combined for five Appalachian (Pennsylvania) streams to determine the frequency of occurrence of acutely toxic aluminum conditions for brook trout (Salvelinus fontinalis). Concentrations of total dissolved aluminum (AlTD) increased with stream flow in all streams, but reached a plateau or decreased during extreme high flows in some streams. AlTDwas dominated by inorganic monomeric species in all streams except Benner Run and Baldwin Creek. Episodic AlTDconcentrations and durations were compared with a toxicity curve developed using caged wild and hatchery-reared brook trout. Results predicted that lethal episodes occurred on Linn, Stone, and Roberts runs, but not on Benner Run and Baldwin Creek. With the exception of Stone Run, brook trout populations were largest in streams without predicted lethal episodes (Benner Run and Baldwin Creek) and were smallest in streams with predicted lethal episodes (Linn and Roberts runs). This analysis could be adapted for prediction of toxic conditions in streams for other pollutants where toxicity varies with both concentration and duration of exposure.