Alps Of Austria Research Articles

Internal structure and depositional environment of Late Carboniferous mounds from the San Emiliano Formation, Cármenes Syncline, Cantabrian Mountains, Northern Spain

Well-exposed mounds are common in limestone of the Late Carboniferous San Emiliano Formation, Cantabrian Mountains (Northern Spain). They occur as obvious primary topographic features. Careful study of the mound intervals and surrounding strata revealed the internal structures of mounds and the factors controlling their growth. The substrate (2 – 3 m) of the mounds consists of greyish to reddish, bedded oolitic and oncolithic packstone and grainstone. Crinoids, fragments of the alga Epimastopora, and, rarely, bryozoans are present. Ooids and oncoids indicate a wave-dominated high-energy environment. Presence of quartz indicates the influence of terrigenous siliciclastic input. Mound intervals (6 – 12 m thick) are characterized by skeletal – microbial boundstone. Donezellid algae, agglutinated worm tubes, and calcisponges are the dominant fossils. Smaller foraminifers, gastropods, and brachiopods are also present. A peloidal-clotted matrix is characteristic and accounts for more than 30% of the mound volume. Intraframe pores are mainly filled by peloidal sediment and early marine cement. Intermound strata are approximately one-third as thick as time equivalent mounds. Mound fossils (algae, agglutinated worm tubes, and sponges) are uncommon. However, intermound strata are generally more diverse than the mounds, containing fusulinids, smaller foraminifers, bryozoans, gastropods, crinoids, and bioclasts. Some of these fossils have micritic envelopes. Bedded packstone and grainstone, 3 – 6 m thick, with siliciclastic debris, rugose corals, and chaetetid sponges characterize the capping facies. Coated grains and small ooids are uncommon. This facies indicates shallowing to a higher energy environment and/or a higher input of siliciclastics, inhibiting mound growth. Mounds are interpreted to have accreted in a quiet environment below wave base. This position is comparable to the depositional environment inferred for many Late Paleozoic mounds described elsewhere, e.g., from Texas and New Mexico, Canadian Archipelago, and Carnic Alps in Austria. Mound relief is explained by (1) accumulation of peloidal-clotted sediments limited to boundstone and probably related to microbial activities, (2) widespread marine cementation within this area, and (3) low export of mound fossils to intermound areas. The position of the mounds within the sequence, and their initiation, size and termination, seem to be mainly controlled by sea-level fluctuations and siliciclastic input. D 2001 Elsevier Science B.V. All rights reserved.

Mycosphaerella dearnessii, a Needle-cast Pathogen on Mountain Pine (Pinus mugo) in Italy.

The pathogen Mycosphaerella dearnessii Barr. (syn. Scirrhia acicola; anamorph Lecanosticta acicola), the causal agent of brown spot needle blight, was observed on Pinus mugo in the Botanical Garden in Gardone (Brescia), on the western side of Garda Lake in northeastern Italy. Symptoms were first noticed in the spring of 1997 by Klaus Lang (University of Freising, Germany). Two years later, all 12 of the P. mugo present in the Garden exhibited extensive necrosis, and defoliation of the crown starting from the bottom upward was more prevalent on the shaded portion of infected trees. The trees were about 50 years old and 2.0 to 2.5 m in height. Symptomatic needles were confined to the 2- and 3-year old internodes. Infected needles had several dark to purplish-brown spots surrounded by green tissue and usually had dead tips. Pycnidia and conidia of Lecanosticta acicola were observed. Conidia were 4-celled, curved, pointed at one end and blunt at the other, pale olive-brown and 20 to 30 × 3 to 4 μm. The fungus was isolated in pure culture. The pathogen causes serious losses in China, eastern United States, and central and South America, but was observed for the first time in Europe only 30 years ago. It is a major cause of needle blight on several European pine species, especially P. sylvestris, P. nigra, and P. mugo. In the last 7 years, there have been reports of the fungus in pine stands, first in France, Aquitaine, and the western Pyrenees on P. radiata (3), and more recently on P. mugo in the Alps in Austria (1), Switzerland (2), and southern Germany (4). This record of the fungus near Lake Garda poses a new serious threat especially for the pine plantations of P. nigra and P. sylvestris in the more humid locations in the Alps, Apennines, and elsewhere in the mountains of southern Europe where the climatic conditions are similar to that of central Europe. This is the first report of M. dearnessii on the southern slopes of the Alps and in Italy.

Germination and Establishment of Seedlings on a Glacier Foreland in the Central Alps, Austria

Seedling recruitment and establishment were studied on the moraines of a glacier foreland in the central Alps in Austria. Permanent plots were established on moraines that had been ice-free for 25 and 40 yr. Comparisons were made between vegetated and bare-ground plots on each moraine over three growing seasons (1996-98). On half of the plots seeds of glacier foreland species were sown and their germination rates followed. Wide annual fluctuations in seedling recruitment were noted over the 3 study years. In the numbers of seedlings no significant differences between the sites were noted. Species composition of the seedlings showed a significant correlation with the vegetation of the sites. Seedling recruitment on the vegetated plots was greater than on the bare-ground plots. Established plants and stones represented safe sites for seedling recruitment. On the older moraine established plants had a negative effect on the survival of seedlings. After two winters seedling survival rates ranged from 0 to 40%. In most cases greater numbers of seedlings were found on the seeded than on the unseeded plots. The seeding experiment showed that seeds of late successional species are able to become established on younger moraines.

Germination and Establishment of Seedlings on a Glacier Foreland in the Central Alps, Austria

Seedling recruitment and establishment were studied on the moraines of a glacier foreland in the central Alps in Austria. Permanent plots were established on moraines that had been ice-free for 25 and 40 yr. Comparisons were made between vegetated and bare-ground plots on each moraine over three growing seasons (1996–98). On half of the plots seeds of glacier foreland species were sown and their germination rates followed. Wide annual fluctuations in seedling recruitment were noted over the 3 study years. In the numbers of seedlings no significant differences between the sites were noted. Species composition of the seedlings showed a significant correlation with the vegetation of the sites. Seedling recruitment on the vegetated plots was greater than on the bare-ground plots. Established plants and stones represented safe sites for seedling recruitment. On the older moraine established plants had a negative effect on the survival of seedlings. After two winters seedling survival rates ranged from 0 to 40%. In most cases greater numbers of seedlings were found on the seeded than on the unseeded plots. The seeding experiment showed that seeds of late successional species are able to become established on younger moraines.

Climatic Significance of Light Rings in Timberline Spruce, Picea abies, Austrian Alps

A ring-width and light-ring chronology was built from timberline spruce [Picea abies (L.) Karst.] in the eastern Alps in Austria. Comparison of the chronology spanning the period from 1750 to 1997 with a long-term temperature record revealed a close relationship between September and October temperatures and light-ring occurrence. Tracheidogram analysis of radial tracheid diameter and cell-wall thickness of light rings formed in 1912 compared with a reference year confirmed the influence of temperatures of this period on light-ring formation. It is concluded that light rings in timberline spruce are pointers for abnormally low temperatures during the last part of the growing season.

Population size, density, spatial distribution and dispersal in an Austrian population of the land snail Arianta arbustorum styriaca (Gastropoda: Helicidae)

One population of the land snail Arianta arbustorum styriaca (Frauenfeld, 1868), endemic in the Northeastern Alps in Austria, was investigated with regard to population size and density, spatial distribution and movement patterns of the individuals in order to obtain basic information on their population biology. The study was carried out at a site situated about 880 m above sea level in Styria, in the Gesause mountains over two years, using the capture-recapture technique. Population density based on the JollySeber model showed variation ranging from 0.12‐4.03 individuals/m 2 over the whole study period. The recapture rate after one year was generally high (up to 85% per sampling date). In most cases individuals were aggregated. The snails showed a high site fidelity; average calculated minimum areas were 0.115 m 2 /day. The sum vector of all individual dispersal observations over the entire study period did not indicate a significant preference for any direction. Only during winter was a significant downhill displacement (possibly passive) detected.

Climatic Significance of Light Rings in Timberline Spruce, Picea abies, Austrian Alps

A ring-width and light-ring chronology was built from timberline spruce [Picea abies (L.) Karst.] in the eastern Alps in Austria. Comparison of the chronology spanning the period from 1750 to 1997 with a long-term temperature record revealed a close relationship between September and October temperatures and light-ring occurrence. Tracheidogram analysis of radial tracheid diameter and cell-wall thickness of light rings formed in 1912 compared with a reference year confirmed the influence of temperatures of this period on light-ring formation. It is concluded that light rings in timberline spruce are pointers for abnormally low temperatures during the last part of the growing season.

NITROGEN LEACHING FROM FOREST SOIL CORES AFTER AMENDING ORGANIC RECYCLING PRODUCTS AND FERTILIZERS

Many alpine forests are severely depleted of nutrients by extensive logging and by grazing of cattle and wildlife. Fertilization may be a remedy, but nitrate leaching may pose problems for the groundwater. However, use of slow-release fertilizers may avoid this problem, whilst improving the Ca, Mg, K, and P status of these soils. Intact soil cores (11 cm diameter, 40 cm depth) from a mixed forest and a Norway spruce stand in the Northern Calcareous Alps of Austria were used in a laboratory experiment to study the effects of adding organic fertilizers and recycling products on patterns of nitrate and ammonium release. The amended (corresponding to 300 kg N ha−1) and control cores were incubated for 29 weeks at 15°C. Soil water (retrieved 5 cm below the soil surface) and leachate were analysed for nitrate and ammonium in regular intervals. After the incubation, soil microbial biomass, basal respiration and nitrogen mineralization were determined. Some of the organic fertilizers, especially those that had undergone composting processes (compost of organic waste, compost of bark+sewage sludge, compost of sawdust+sewage sludge, Biovin®) and Biosol®, caused only minor increases of nitrate and ammonium in the soil water and leachate. Others, like uncomposted sewage sludge products (Primafert® and sewage sludge+shale), resulted in elevated (up to 150 mg nitrate-N l−1) nitrate concentrations in the soil water and in the leachate. Fertilization with N-rich fertilizers (Biosol®, Primafert®, sewage sludge+shale) resulted in significant decreases in microbial biomass and basal respiration at the end of the 6-month incubation. Microbial biomass and basal respiration were not affected by the other organic fertilizers.

The Incidence of Herbivory in High-Elevation Populations of Ranunculus glacialis: A Re-Evaluation of Stress-Tolerance in Alpine Environments

Growing conditions in the upper alpine zone are characterized by low temperature. low partial pressures of CO 2 and, in the temperate zone, a short growing period. The plants which have evolved under these conditions presumably share a number of characteristics that were ascribed to stress-tolerance, namely slow growth, extended longevity, resource limitation and low palatability to herbivores. Hence chronic biomass removals by herbivores should be a threat to plant persistence in alpine environments, as predicted by Grime's C-S-R theory. I tested this hypothesis on populations of an alpine buttercup. Ramunculus glacialis. A survey along an altitudinal transect in the Central Alps of Austria indicated that between 15 and 26% of the R. glacialis plants in each population examined exhibited signs of herbivory damage. Merely a small population, isolated by glaciers, at the highest site (3310 m a.s.l.) showed no traces of herbivory. At two sites (2600 m and 3180 m a.s.l.) twenty plants each were tagged and examined for a two-year period. Herbivory damage was considerable: on an average nearly 25% of a plant's total leaf area was removed in 1987. primarily by snow mice (Microtus nivalis). Inflorescences of 65-85% of all flowering plants were removed as well. At the lower site (2600 m. roughly 600 m above the treeline) up to 5 g dry matter and 140 mg nitrogen m -2 were consumed in one season. Despite the magnitude of these losses both reproductive investment and the number of leaves initiated per plant did not change appreciably in the subsequent year. Since populations of R. glacialis are able to support populations of herbivores at the altitudinal limits of plant growth without obvious reductions in vigor. these plants and other food species (e.g. Oxyria digyna) cannot fit the stress-tolerator scheme proposed by Grime. The widespread occurrence of herbivory at high elevations and plant traits challenge the concept of stress-tolerance as it is commonly applied to alpine environments.

Effects of forest fertilization on nitrogen leaching and soil microbial properties in the Northern Calcareous Alps of Austria

Several boreal and alpine forests are depleted in nutrients due to acidification. Fertilization may be a remedy, but rapidly-soluble salts (N, P, K, Mg) may pose nitrate problems for the groundwater or decrease microbial activity. With the aim to investigate potential nitrogen leaching after fertilization we set up an experiment employing intact soil cores (11 cm diameter, 20–40 cm long) from a mixed forest and a Picea abies stand (soil type Rendsina) in the Northern Calcareous Alps of Austria. The cores were fertilized with a commercial NPK fertilizer or a methylene-urea-apatite-biotite (MuAB) fertilizer at a rate corresponding to 300 kg N ha-1 and incubated for 28 weeks together with unfertilized controls. Both soil water (retrieved 5 cm below the soil surface) and leachate were analyzed for nitrate and ammonium in regular intervals. After the incubation, soil microbial biomass and basal repiration were determined and a nitrogen mineralization assay was performed. For the control, in the soil water and leachate maximum NH4 + and NO3 - concentrations of 5 and 11 mg N L-1, respectively, were found. Compared to that, MuAB fertilizer resulted in a slow increase of NH4 + and NO3 - in the soil water (up to 11 and 35 mg N L-1 respectively) and in the leachate (4 mg NH4 +-N L-1 and 44 mg NO3 --N L-1). Highest nitrogen loads were found for the fast release NPK fertilizer, with NH4 + and NO3 - concentrations up to 170 and 270 mg N L-1, respectively, in the soil water. NH4 +-N levels in the leachate remained below 5, while NO3-N levels were up to 190 mg L-1. Fast- release NPK caused a significant decrease of microbial biomass and basal respiration. These parameters were not affected by MuAB fertilizer. The results suggest that the MuAB fertilizer may be an ecologically appropriate alternative to fast-release mineral fertilizers for improving forest soils.

A comparative study of instruments for measuring the liquid water content of snow

Different dielectric sensors for measuring the liquid water content of snow are compared and described in detail. The instruments make use of the significant difference in the dielectric properties of ice and liquid water at radio frequencies; they are operated with frequencies ranging from 1 MHz up to 1.3 GHz. Plate condensers in connection with ac bridges are used as sensors in the frequency range up to 100 MHz whereas open resonators are used in the GHz regime. Test measurements with the different sensors on homogeneous samples like dry sand and mixed and prepared snow showed the same results for the dielectric constant: the discrepancies are less than 1%. In the natural, inhomogeneous snow cover, the special properties of the different sensors appear. Snow wetness is calculated from the measured dielectric constant and the snow density using the model of Polder and van Santen. The comparative field measurements were made with Alpine snow in the Stubai Alps in Austria.

Aspects of late triassic palynology. 3. Palynology of latest triassic and earliest jurassic deposits of the northern limestone alps in Austria and southern Germany, with special reference to a palynological characterization of the Rhaetian stage in Europe

The present paper provides a palynological analysis of samples from the “Kössener Schichten”, “Schattwalder Schichten” and the ammonoid ( Psiloceras planorbe)-bearing beds of the “Fleckenmergel/Fleckenkalk” found in the vicinity of Salzburg (Austria and adjacent part of Germany). It is shown that the compositional development of latest Triassic—earliest Jurassic palynological assemblages from Alpine sequences matches the situation in the Germanic realm. A characteristic phase in this development is interpreted in terms of the Rhaetipollis germanicus Assemblage Zone. It is considered that this zone could well be regarded as a palynological characterization of the Rhaetian Stage in Europe and North America. Although palynology does not support the Rhaetian concept based on the occurrence of the species Choristoceras marshi exclusively, the traditional ammonoid-based Triassic—Jurassic boundary can be palynologically recognized.

Oceanic mafic rocks in the Eastern Alps

The Eastern Alps in Austria have been interpreted as a pile of thrust sheets resulting from the collision of two continental masses. The only remains of the ocean-floor which may once have separated these continents could be the highly deformed greenschists, metasediments and serpentinites found in the lower thrust sheets. To test this hypothesis, a total of sixty mafic rocks from the Grosglockner, Mooserboden, Fusch, Hochtor, Matrei Zone and Strobl localities have been analysed for the stable trace elements, Ti, Zr, Y, Nb and Cr, and the less stable elements K, Rb, and Sr. Visual and statistical comparison of the stable elements with known magma types reveals that five of the sample groups classify clearly as tholeiitic ocean-floor basalts, while one group, the Fusch locality, classifies as within-plate (probably ocean island) basalts. It is suggested that the tectonic units containing such rocks comprise a melange of disrupted oceanic crust, upper mantle and seamounts, pelagic sediments and continental margin sediments. The rocks may have formed in a large ocean basin, rather than a marginal basin behind an island arc.

Geology of Bulgaria: a Review

Bulgaria is in southeastern Europe between reasonably well-described areas of predominantly Alpine crustal deformation on the north and northwest (Carpathians in Romania, Hungary, and Czechoslovakia; Alps in Austria), on the east (Pontides and Taurides in Turkey), and on the west and south (Dinaric Alps in Yugoslavia; Pindos Mountains in Greece) but has not been well described in easily available literature. There are three major east-west trending morphotectonic units. The low-relief Moesian platform of northern Bulgaria and southern Romania owes its heritage to Hercynian deformation. It is mantled by flat-lying, shelf-type Mesozoic and Tertiary sedimentary (mostly carbonate) rocks. Along its southern boundary a foredeep developed during Jurassic-Cretaceous time in which thick flysch-like sediments accumulated. There is small oil and gas production. The Lom basin, North Bulgarian swell, and Varna trough are other major structural elements within the platform. The Rhodope massif of southern Bulgaria and northern Greece is a rugged mountainous terrain of Precambrian and early Paleozoic crystalline rocks. It is a fragment of a once much larger crustal block that began to break up in the Paleozoic and which has experienced uplift of 2,000 m in the Pliocene-Pleistocene. Between the Rhodope and Moesian crustal blocks the narrow (10-20 km) Balkan Mountains (Stara Planina zone) consist of tightly folded and metamorphosed Paleozoic sedimentary rocks that have been deformed recurrently during the Hercynian and Alpine orogenies, culminating in 3 to 4 km of vertical uplift since the Miocene. The sub-Balkan fault bounds the south side of the Balkans and is at many places a spectacular scarp. The Balkanide zone has been compressively molded between the large, relatively stable Rhodope massif and Moesian platform. Locally, north-moving gravitational glide masses lie on the platform but there has been minimal crustal shortening. A fourth morphotectonic unit, the Kraishtide zone, trends northwest through western Bulgaria and into adjacent Yugoslavia. This rugged area, 15-60 km wide, is a megashear zone within which both right-lateral strike-slip and vertical movements have been common since the Paleozoic. It parallels the better known Vardar zone of Yugoslavia. In addition to the long-lived, deep-seated faults that parallel the trend--and which are the boundary for some--of these four crustal units, a northeast-southwest fault system (Tvarditsa and Etropole), further breaks the Bulgarian crust into a giant block mosaic. Predominantly vertical movement along the major faults alternately has elevated or depressed individual blocks of the mosaic and has influenced profoundly the location and the character of sedimentation, igneous activity, occurrence of mineral deposits, and erosion.

Recognition of Deep-Water Limestone Sequences, Austrian Alps: ABSTRACT

Jurassic fine-grained limestone and radiolarian chert in the northern Limestone Alps of Austria contain evidence of bathyal to abyssal depositional sites. Evidence for a deep-water origin of the Alpine Jurassic sequence has been noted by a succession of European geologists including Fuchs (1887), Steinmann (1925), and Trumpy (1960), and has strongly influenced the European view of geosynclinal sedimentation. The major lines of evidence for deep-water deposition of this Jurassic section are: 1. Fauna and rock composition: The fauna consists predominantly of planktonic and nektonic forms such as ammonites, radiolaria, and calpionellids. Electron microscopy reveals that much of the fine-grained limestone consists of nannoplankton. End_Page 464------------------------------ 2. Very slow sediment accumulation rates: This is apparent in several ways: occurrence of manganese nodules and crusts on bedding planes; very thin but complete stratigraphic sections representing long time intervals; and cosmic spherule abundances in the rocks. Average sediment accumulation rates on the order of 0.1 to 2.0 cm./103 years are suggested by rough calculations; however, it is evident that the actual rates changed considerably within the time intervals considered. 3. Solution effect: Solution of all or nearly all calcium carbonate minerals produced the radiolarian chert as an insoluble residue; this is believed to be analogous with certain areas of the present deep-sea floor below the depth of complete CaCO3 dissolution. In other parts of the Jurassic section, aragonitic skeletal parts (ammonite shells) were dissolved; calcitic parts (ammonite aptychi) are well preserved. The latter situation is believed to be analogous with certain present deep-sea areas where dissolution of aragonitic pteropods occurs at shallower depths than calcite dissolution. 4. Subsidence rates: This can be fairly well established for the Triassic Period in the Austrian Alps because the total thickness of the shallow-water Triassic deposits (reefs, evaporites, etc.) is indicative of total subsidence. If projected unchanged into the Jurassic Period, this rate establishes at least minimum depths during the Jurassic and indicates that subsidence rates greatly exceeded sedimentation rates. Other evidence suggests that the subsidence rate actually increased during Jurassic time, at least in the beginning. Together these criteria suggest maximum water depths of 4,500-5,500 meters in the northern Limestone Alps during Jurassic time. End_of_Article - Last_Page 465------------

Conodont Zonation of Upper Devonian in Central Europe: ABSTRACT

Conodont investigations in the German standard End_Page 641------------------------------ Upper Devonian sections resulted in establishing a conodont zonation. Altogether 26 conodont zones and subzones have been recognized. The conodont succession was obtained mainly from known ammonoid zones beginning with the uppermost Middle Devonian cephalopod zone of Maenioceras terebratum and extending through the entire Upper Devonian into the Wocklumeria Stage. To determine the regional constancy of conodont succession, more than 100 Upper Devonian sections from Germany were studied. The same Upper Devonian conodont succession, recognized in much of Europe, as detailed investigations have subsequently proved. These zones have been found in eastern Germany, Carnic Alps in Austria, Montagne Noire and northern Massif Central in France, Pyrenees and Cantabria in Spain, and Moravia and Bulgaria in southeastern Europe. In addition, in the Belgian Upper Devonian, where the sediments were laid down in a different environment, similar zonal associations and successions coincide with others. Results of studies in the Upper Devonian outside of Europe (mid-western and northern Africa) support the opinion that conodont succession in the Upper Devonian is the same as that in Europe. Presently known deviations are caused by peculiarities within the local geological sequences (breaks in sedimentation, slow deposition, reworking, redeposition, etc.). A recent study of the ammonoid-bearing Upper Devonian sequence of northwestern Australia carried out by Glenister and Klapper indicates that the European conodont zonation also can be applied effectively in this region. Conodonts can be used to zone the Upper Devonian in greater detail than the standard cephalopod succession. Recent studies reveal that boundaries between some ammonoid stages are inexactly defined or that there are gaps in the ammonoid succession. By means of conodonts such gaps may be bridged with the result that the best and most complete biostratigraphic subdivision of the Upper Devonian at present is based on conodonts. End_of_Article - Last_Page 642------------

Die relikt-schwarzföhrenwälder des alpenostrandes

The Illyrian black pine occurring mainly in Yugoslavia has a disjunct area on the east side of the Alps in Austria. Within the “isolated sub-Illyrian colony” along the Thermenlinie (thermal spring line) south of Vienna, it prefers the altitude of the montane beech zone between 250 m–1250 m. Its ecological requirements with regard to soil dryness are met by dolomitized substrata, those for air humidity by a natural occurrence in the montane zone, on west-facing slopes in general, and on the upper parts of slopes; in this it shows a fundamental ecological difference from Quercus pubescens, which, though also Illyrian, requires dry air. In its distribution optimum along the east side of the Alps, the black pine forms closed wood communities (Seslerio-Pinetum and Chamaebuxo-Pinion), extending into the dealpine zone. In the (upper and lower) marginal zones of its occurrence it joins other communities, which phenomenon is facilitated by the fact that its top does not obstruct the passage of light. The major disjunctions of the Tertiary species are doubtless of preglacial origin, the minor disjunctions within the Illyrian subspecies may date from more recent (interglacial or postglacial) times.