Alpine Belt Research Articles

Growth‐ring variations of dwarf shrubs reflect regional climate signals in alpine environments rather than topoclimatic differences

AbstractAim Our main aim is to determine if ring‐width variations in Empetrum hermaphroditum reflect regional or local topoclimate signals in an alpine environment. In the case that topoclimate provides the dominant signal, a secondary aim is to link these to spatial distribution patterns of different vegetation types.Location The study area is situated in the middle alpine belt in the Vågåmo region, Central Norwegian Scandes. Sampling sites cover different topoclimates: ridges, north‐facing slopes and south‐facing slopes.Methods We constructed ring‐width chronologies of E. hermaphroditum for each type of microsite for the common period 1951–2004. Climate data were prepared on an hourly, daily and growing‐season time scale. Climate–growth relationships were evaluated using bivariate correlations and regression tree methods for continuous time‐series analyses. In addition, extreme growth anomalies (pointer years) were compared with the climate conditions in those years. The impact of water supply on wood anatomy was determined by correlating the conductive area (percentage of vessel per growth ring) with a running mean (sum) of 10‐day intervals for temperature and precipitation.Results This study indicates that mean summer (June–August) temperatures determine the width of the growth rings of E. hermaphroditum irrespective of topoclimate. The length of the growing season, which is the most differentiating climatic factor between microsites, does not substantially alter the anatomical ring structure. Microsite differences in mean growth rates are attributed to the higher frequency of warm days. Extremely warm days limit ring‐width development at south‐facing slopes, while plants at ridges and north‐facing slopes still benefit from higher temperatures. As a consequence, pointer years are not developed synchronously at all microsites. Vessel formation is affected by available moisture, especially in the later part of the growing season.Main conclusions Topoclimate induces slight modifications of annual growth‐ring increments of E. hermaphroditum at different microsites. In contrast to the distribution patterns of vegetation types that are determined by snow cover, growth‐ring variations are related to summer temperature conditions, and the prominent regional climate signal is still reflected at all microsites. This offers the opportunity to reconstruct climatic change in alpine regions from dwarf shrub ring‐width chronologies.

Geochronology of Neogene-Quaternary volcanism of the Geghama Highland (Lesser Caucasus, Armenia)

This work continues the systemic isotopic‐geochronological studies of Late Cenozoic volcanism in the Lesser Caucasus [1‐5] undertaken to elaborate the general regional scale of magmatic activity in this region during the Neogene‐Quaternary and to establish neovolcanic centers potentially hazardous in terms of possible catastrophic eruptions. The young magmatism in the Caucasian segment of the Alpine belt that developed in the course of collision between the Eurasian and Arabian lithospheric plates is genetically related to the activity of the mantle “hot field” [6], which determined the prevalence of basic rocks among volcanics. The most intense pulses of volcanic activity during the Neogene‐Quaternary are recorded in the Lesser Caucasus and eastern Anatolia, while young igneous rocks are distributed only in small areas of the Greater Caucasus. The Lesser Caucasus volcanic province, which extends in the arcuate manner from Ajaria to Nagornyi Karabakh and includes abundant Neogene‐Quaternary volcanics [7], is divided into six neovolcanic areas (from the northwest to southeast): Erusheti‐Arsiani, Javakheti, Aragats, Geghama, Vardenis, and Syunik. Young volcanics of the Lesser Caucasus are highly variable in terms of their chemical composition with varieties of normal and elevated alkalinity being most abundant. Our previous studies [1‐5] provided ages for Neogene‐Quaternary igneous rocks from several reference volcanic centers of the Aragats and Javakheti areas. These dates allowed us to define regional geochronological scales for young volcanism. In this work, we consider isotopic‐geochronological data obtained for Neogene‐Quaternary igneous rocks from the Geghama neovolcanic area located in the territory of the Republic

The Upper Paleozoic preflysch and overthrusting in the Türkstan-Alay ranges, southern Fergana

The Upper Paleozoic preflysch sedimentary rocks in the Turkstan-Alay ranges are combined in a common section with limestone of autochthon and synsedimentation carbonate nappes, thus forming the upper-most layers of the stratigraphic section of the latter. By their lithology, relatively small thickness, facies variability, and position at the boundary between carbonate and flysch-olistostrome sequences (in the autochthon), these rocks correspond to a certain extent to preflysch of the Urals and the Mediterranean Alpine Belt. This association of clayey, carbonate, and terrigenous rocks is strictly constrained in stratigraphy (the upper portion of the lower Moscovian substage and the lower portion of the upper Moscovian substage) and localization (the southern slopes of carbonate platforms). The formation of this rock association immediately predated the Late Paleozoic overthrusting and deposition of terrigenous flysch. In paleotectonic terms, preflysch is an indicator of the initial stage of tectonic and magmatic activation that led to the replacement of carbonate sedimentation with deposition of terrigenous and clayey sediments, coeval volcanism, and stratiform ore formation. The following sequence of events has been outlined in the Early and Middle Carboniferous: (1) thrusting of volcanic-sedimentary rocks filling troughs over the northern margins of carbonate platforms, (2) lateritic weathering and deposition of marine bauxite in the Bashkirian and early Moscovian, (3) repeated overthrusting and deposition of preflysch on southern slopes of platforms, (4) invasion of the frontal flysch trough from the south, (5) scouring of preflysch and the underlying limestone, and (6) formation of flysch-olistostrome sequences and tectonic and gravity nappes in the late Moscovian time. This interpretation takes into account the southward vergence of thrust sheets and nappes, the structure and localization of allochthonous fragments of marginal zones of carbonate platforms, and the pre-Bashkirian thrusting of volcanic and sedimentary rocks over the condensed pelagic deposits of the Shalan Group. It is suggested that bauxite and preflysch materials had the same source and were deposited in the Middle Carboniferous on the offshore carbonate shoals.

Changes in plant species richness over the last century in the eastern Swiss Alps: elevational gradient, bedrock effects and migration rates

Areas of 2,800–3,000 m a.s.l. represent the alpine-nival ecotone in the Alps. This transition zone connecting the closed swards of the alpine belt and the scattered vegetation of the nival belt may show particularly strong climate warming driven fluctuations in plant species richness compared to the nival belt. To test this hypothesis, 12 summits within this range were investigated in the canton of Grisons, Switzerland in 2004. Complete lists of vascular plant species consisting of 5–70 species were collected on each summit and the elevation of the uppermost occurrence of each species was recorded. These data were compared to historical records over 120 years in age. Within this time, vascular plant species richness increased by 11% per decade on summits in the alpine-nival ecotone. Despite this considerable change, a comparison with nival summits did not support the hypothesis that species richness increase at the alpine-nival ecotone is higher than in the nival belt. A general trend of upward migration in the range of several metres per decade could be observed. Anemochorous species were more often found to be migrating than zoochorous or autochorous species and migration was higher on calcareous than on siliceous bedrock. A comparison between the summits with the adjacent slopes in our study revealed that changes in species number could be used as an indicator for climate-induced changes—if at all—only for the narrow summit areas.

HP/LT metamorphism in the Volparone Breccia (Northern Corsica, France): evidence for involvement of the Europe/Corsica continental margin in the Alpine subdution zone

AbstractThe Alpine belt in Corsica (France) is characterized by the occurrence of stacked tectonic slices derived from the Corsica/Europe continental margin, which outcrop between two weakly or non‐metamorphic tectonic domains: the ‘autochthonous’ domain of the Hercynian basement to the west and the Balagne Nappe (ophiolitic unit belonging to the ‘Nappes supérieures’) to the east. These slices, including basement rocks (Permian granitoids and their Palaeozoic host rocks), Late Carboniferous–Permian volcano‐sedimentary deposits, coarse‐grained polymict breccias (Volparone Breccia) and Middle Eocene siliciclastic turbidite deposits, were affected by a polyphase deformation history of Alpine age, associated with a well‐developed metamorphic recrystallization. This study provides new quantitative data about the peak of metamorphism and the retrograde P–T path in the Alpine Corsica: the tectonic slices of Volparone Breccia from the Balagne region (previously regarded as unmetamorphosed) were affected by peak metamorphism characterized by the phengite + chlorite + quartz ± albite assemblage. Using the chlorite‐phengite local equilibria method, peak metamorphic P–T conditions coherent with the low‐grade blueschist facies are estimated as 0.60 ± 0.15 GPa and 325 ± 20 °C. Moreover, the retrograde P–T path, characterized by a decrease of pressure and temperature, is evidence of the first stage of the exhumation path from the peak metamorphic conditions to greenschist facies conditions (0.35 ± 0.06 GPa and 315 ± 20 °C). The occurrence of metamorphic peak at high‐pressure/low‐temperature (HP/LT) conditions is evidence of the fact that these tectonic slices, derived from the Corsica/Europe continental margin, were deformed and metamorphosed in the Alpine subduction zone during their underplating at ∼20 km of depth into the accretionary wedge and were subsequently juxtaposed against the metamorphic and non‐metamorphic oceanic units during a complex exhumation history.

Soil Acidity, Content of Carbonates, and Available Phosphorus Are the Soil Factors Best Correlated with Alpine Vegetation: Evidence from Troms, North Norway

ABSTRACTWe investigate which bedrock-derived soil nutrients are most important for the floristic composition and diversity of alpine, exposed, rocky habitats in North Norway, and whether the widely used pH parameter is a good estimate of soil chemical conditions in the middle alpine belt. Vegetation at 17 sites was recorded using the grid frequency method. Differences in the diversity of vascular plants, bryophytes, and lichens on the different substrates were compared using Shannon’s diversity index. Local soil consisted of weathered material from one of five bedrock categories: carbonate rocks, calcareous mica schist, noncalcareous mica schist, mafic rocks, and felsic rocks. Particle size, loss on ignition, pH, and levels of calcium, magnesium, potassium, phosphorus, and nitrogen were measured in soil samples. Canonical Correspondence Analysis showed that soil pH and bedrock derived phosphorus in the soil influence the floristic composition. Randomization tests further indicated that the floristic variation explained by bedrock derived phosphorus was not correlated with soil pH. Thus, the pH measure should be used with caution for the characterization of soil conditions. Vegetation growing directly in soil derived from carbonate rocks is distinct from communities on other calcareous soils. Species at such sites should be referred to as carbonate specialists rather than lime demanding.

Aseismic deformation in the Alps: GPS vs. seismic strain quantification

AbstractNeotectonics of the Western and Central Alps is characterized by ongoing widespread extension in the highest zones of the chain and transcurrent/compressive tectonics at the external limits of the belt. The overall geodetically measured deformations also indicate extension across the Western Alps. There is a good qualitative coherency between seismotectonic and geodetic approaches. Here we attempt to quantify the seismic part of the deformation. The seismic strain is compared to the deformation derived from geodesy. In sub‐areas of homogeneous seismic stress/strain, we computed the total seismic moment tensor and related strain tensor. This study provides new quantitative elements about the ongoing geodynamic processes in the alpine belt. The important discrepancies obtained between seismic strains and geodetically‐measured deformations raise the issue of aseismic deformation in the Alps, which could be related to elastic loading, creeping and/or a slower ductile‐style deformation.

Present-day stress field and tectonic inversion in the Pannonian basin

This paper presents a latest compilation of data on the present-day stress pattern in the Pannonian basin, and its tectonic environment, the Alpine–Dinaric orogens. Extensional formation of the basin system commenced in the early Miocene, whereas its structural reactivation, in the form of gradual basin inversion, has been taking place since Pliocene to recent times. Reconstructed compression and associated horizontal contraction are mainly governed by the convergence between Adria and its buffer, the Alpine belt of orogens. The resulting contemporaneous stress field exhibits important lateral variation resulting in a complex pattern of ongoing tectonic activity. In the Friuli zone of the Southern Alps, where thrust faulting prevails, compression is orthogonal to the strike of the mountain belt. More to the southeast, intense contraction is combined with active strike–slip faulting constituting the dextral Dinaric transpressional corridor. Stresses are transferred far from Adria into the Pannonian basin, and the dominant style of deformation gradually changes from pure contraction through transpression to strike–slip faulting. The importance of late-stage inversion in the Pannonian basin is interpreted in a more general context of structural reactivation of back-arc basins where the sources of compression driving basin inversion are also identified and discussed. The state of recent stress and deformation in the Pannonian basin, particularly in its western and southern part, is governed by the complex interaction of plate boundary and intra-plate forces. The counterclockwise rotation and north-northeast-directed indentation of the Adriatic microplate appears to be of key importance as the dominant source of compression (“Adria-push”). Intra-plate stress sources, such as buoyancy forces associated with an elevated topography, and crustal as well as lithospheric inhomogeneities can also play essential, yet rather local role.

Петрофитные сообщества высокогорных известняковых массивов Западного Кавказа

The paper presents description of new syntaxa of pertrophyte associations from West Caucasus lime­stone massifs. The work is based on the author’s long-term observations between years 1998 and 2003, made in the basins of the rivers Belaya, Bolshaja Laba and Malaya Laba within the National Nature Park «Bol­shoi Tkhach» and limestone massifs of Caucasian State Natural Biosphere Reserve. Original geobotanical rele­veйs have been used for the classification. Collec­tion and material processing involved Braun-Blanqet me­thod. The size of sampling plots varied from 4 to 25 m2. The paper is based upon 120 releveés. New syntaxa names have been given in accordance with the Code of Phytosociological Nomenclature (Weber et al., 2000). Ass. Veronica minutae—Chaerophylletum humilis Onipchenko 2002 is common for upper alpine belt of the Reserve and distributed over mobile calcareous screes at 2400—2800 m alt. occupying small areas of Oshten, Fisht, Pshekha-Su and Yatygvarta mountains. Ass. Helianthemetum cani ass. nov. includes open chionophobic groupings of alpine belt, developing on windward mountain slopes and crests at 2000—2800 m alt., occurs on rocky outcrops and dry sedentary screes, and covers significant areas of Lagonaki Pla­teau, mountains Bolshoi Tkhach, Yatygvarta and Snegovalka Ridge. These open associations preferen­tially occupy slopes of «warm» (southern, southern-west, southern-east) expositions of different abruptness from almost horizontal up to 70° (in average 25°). Ass. Saxifragetum sibiricae typicum Onipchenko et Lubez­nova 2002 includes chionophytic groupings of seden­tary screes, characterized by significant snow accu­mulation in winter, forms patches of vegetation around snowbeds and glaciers of Lagonaki Plateau in the Reserve, occurs sporadically on the studied territory. Ass. Saxifragetum sibiricae arabidetosum caucasicae subass. nov. combines open communities of alpine belt at unstable damp rocky substrates and predominantly occupies abrupt slopes (20—35°) of northern—nor­thern-east exposition of damp, slightly mobile screes close to glaciers at 2000—2700 м alt. on Lagonaki Plateau in the Reserve. Ass. Saxifrago cartilagineae—Asplenietum rutae-murariae ass. nov. occurs on rocks in subalpine belt predominantly on abrupt slopes (20—90°, average 69°) of different expositions at 1400—1700 m alt. on Lagonaki Plateau in the Reserve. Ass. Valeriana saxicolae—Helianthemetum cani ass. nov. includes plant communities of limestone rocks occupying abrupt slopes (20—70°, in average 53°) of predominantly southern expositions at 2000—2700 m alt. on Lagonaki Plateau, Triu-Yatygvarta massif, mountain Bolshoi Tkhach.

Ring-Width Chronologies of the Alpine Dwarf Shrub Empetrum Hermaphroditum FROM THE NORWEGIAN MOUNTAINS

In this study, we present the first ring-width chronologies of the dwarf shrub species Empetrum hermaphroditum. For a proper synchronization of the growth rings, serial sectioning was applied in order to deal with the high intern al growth variability and the high proportion of discontinuous rings. The plants were collected from three micro-sites in the middle alpine belt of the Norwegian Scandes wh ich differed regarding solar insolation, snow accumulation and wind exposure. The constructed ringwidth chronologies cover aperiod of max. 80 years. Irrespective of microclimatic differences, the chronologies are highly correlated among each other and with temperatures during the growth period (June-August). However, ecological differences between the micro-sites are reflected by the mean annual growth increments of the plants. We compared the Empetrum chronologies with a ring-width chronology of Betula pubescens trees from the local tree line. Despite the differences in life form and local site conditions, the growth patterns are very similar, an observation which underscores the dominant influence of temperature on growthring formation. Due to the strong climatic signal recorded in the growth curves of E. hermaphroditum, this dwarf shrub provides a significant potential for climate-growth studies in arctic and alpine regions beyond the tree line.

Band-e-Amir Lakes and Dragon Valley (Bamiyan): myths and seismicity in Afghanistan

Abstract Located SW of the Hindu Kush range, the Band-e-Amir lakes and other continental bioherms around Bamiyan are famous for their ordering into terraces and their great variety of colours. Numerous legends, the earliest likely dating to the establishment of the Zoroastrian religion, refer to the topography, ecology, and colours of the lakes and seismic activity of the area. The lakes have been formed by the chemical and biologically-induced build-up of semicircular or successive linear travertine dams. The discovery of a highly truncated karstic network located at an elevation of around 4000 m. along the base of Maastrichtian carbonate cliffs surrounding the lakes, may explain the presence of this carbonate sedimentation which has fluctuated with time and was responsible for legendary floods. Localized at the eastern end of the Herat strike-slip fault, the timing and duration of the build-ups and lakes are under the influence of intense seismic activity, partially due to the seismic activity of the nearby Hindu Kush, in relation to the northern drift of the Afghan Gondwanian block towards the Eurasiatic plate. These bioherms and lakes occur in an area of high risk; a zone of floods, freezing temperatures, earthquakes and rock avalanches caused by the high altitude and location in the Himalayan alpine belt. These natural features have affected local populations beginning with the movement into the area of more or less sedentary people, apparently coming from the Bactrian province. Such a fragile biological and sedimentological environment should be maintained by organized governmental assistance, with a primary goal of protecting the local inhabitants, but also preserving this exceptional environment for others to enjoy.

Zircon age and Nd–Hf isotopic composition of the Yunnan Tethyan belt, southwestern China

The Baoshan block of the Tethyan Yunnan, southwestern China, is considered as northern part of the Sibumasu microcontinent. Basement of this block that comprises presumably greenschist-facies Neoproterozoic metamorphic rocks is covered by Paleozoic to Mesozoic low-grade metamorphic sedimentary rocks. This study presents zircon ages and Nd–Hf isotopic composition of granites generated from crustal reworking to reveal geochemical feature of the underlying basement. Dating results obtained using the single zircon U–Pb isotopic dilution method show that granites exposed in the study area formed in early Paleozoic (about 470 Ma; Pingdajie granite) and in late Yanshanian (about 78–61 Ma, Late Cretaceous to Early Tertiary; Huataolin granite). The early Paleozoic granite contains Archean to Mesoproterozoic inherited zircons and the late Yanshanian granite contains late Proterozoic to early Paleozoic zircon cores. Both granites have similar geochemical and Nd–Hf isotopic charateristics, indicating similar magma sources. They have whole-rock T DM(Nd) values of around 2,000 Ma and zircon T DM(Hf) values clustering around 1,900–1,800 and 1,600–1,400 Ma. The Nd–Hf isotopic data imply Paleoproterozoic to Mesoproterozoic crustal material as the major components of the underlying basement, being consistent with a derivation from Archean and Paleoproterozoic terrains of India or NW Australia. Both granites formed in two different tectonic events similarly originated from intra-crustal reworking. Temporally, the late Yanshanian magmatism is probably related to the closure of the Neotethys ocean. The early Paleozoic magmatism traced in the Baoshan block indicates a comparable history of the basements during early Paleozoic between the SE Asia and the western Tethyan belt, such as the basement outcrops in the Alpine belt and probably in the European Variscides that are considered as continental blocks drifting from Gondwana prior to or simultaneously with those of the SE Asia.

Annual pollen accumulation rate (PAR) at the boreal and alpine forest-line of north-western Norway, with special emphasis on Pinus sylvestris and Betula pubescens

Pollen monitoring at the north-western fringe of the European boreal forest by means of modified Tauber traps, was carried out during the years 1996–2004 along a coast-inland gradient, including two altitudinal transects inland. The relationship between annual pollen deposition and local flora and vegetation was investigated. Pinus sylvestris stands in the open coastal lowland and mixed birch-pine forest inland are reflected by a mean pollen accumulation rate (PAR) of 200–400 grains cm−2 yr−1, and dense pine-dominated forest inland by ≥2000 grains cm−2 yr−1. The deposition of Betula pubescens-type pollen in the coastal birch woodland is 80–350 grains cm−2 yr−1. During the same time interval, the sub-alpine birch forest inland has a PAR of 240–720 grains cm−2 yr−1. This figure increases to c. 2000 when the two high-productive years 1998 and 1999 are included in the mean. The alpine forest-line ecotone is reflected in the pollen deposition by a decrease in Betula pubescens-type, meadow and heath herbs, and an increase in Salix and alpine herbs with altitude. This floristic change starts in the upper part of the sub-alpine belt and continues gradually into the open alpine belts. The presence of phytophagous insects in the pollen traps is found to influence the pollen record by overrepresentation of insect-dispersed herb taxa, but does not obscure the recognition of local vegetation types. PAR and percentages show the same main trends along the geographical gradients.

The Curinga-Girifalco fault zone (northern Serre, Calabria) and its significance within the Alpine tectonic evolution of the western Mediterranean

Abstract Hercynian basement rocks and Mesozoic ophiolites of the Calabria-Peloritani terrane drifted in the present position during the opening of western Mediterranean basins (namely Liguro-Provencal and Tyrrhenian basins) since the Oligocene. Basement rocks were partly involved by Alpine (late Cretaceous—Eocene) deformation and metamorphism before the onset of the drifting process. Even though the kinematics of the Alpine deformation in Calabria has been already defined, restoration of structural and kinematic data to the original position and orientation before the opening of the western Mediterranean has never been performed. In this work we present new structural and petrological data on a major tectonic contact of Alpine age exposed in central Calabria (Serre Massif). Structural and kinematic data are then restored at the original orientation in the early Oligocene time, to allow a correct tectonic interpretation. In the Serre Massif the Hercynian basement is sliced into three nappes emplaced during the Alpine orogeny. The upper nappe is formed by a nearly continuous section of the Hercynian crust, consisting of medium- to high-grade metamorphic rocks in the lower portion. The intermediate nappe mainly consists of orthogneisses, whereas the lower nappe is chiefly composed of phyllites. The contacts between the Alpine nappes are outlined by well developed mylonitic and cataclastic rocks. The Curinga-Girifalco Line is a well exposed shear zone that overprints mainly metapelitic rocks of the upper nappe and granitoid orthogneisses of the intermediate nappe. Mylonites of the intermediate nappe typically show overgrowths on garnet and hornblende with grossular-rich and tschermakitic composition, respectively. The Alpine mineral assemblage indicates that deformation took place in epidote-amphibolite facies at pressures ranging from 0.75 to 0.9 GPa. In the investigated area mylonites strike roughly WNW–ESE, with shallow dips towards SSW. Kinematic indicators in mylonites are mostly consistent with a top-to-the-SE shear sense in the present geographic coordinates. The mylonitic belt is affected by later extensional faults outlined by South-dipping cataclasite horizons. Published geochronological data indicate that mylonites and cataclasites developed in Eocene and early Miocene times, respectively. Considering rotational parameters coming from paleomagnetic studies and large-scale palinspastic reconstructions, the shear sense of the Curinga-Girifalco Line has been restored to the early Oligocene position and orientation. Through restoration a top-to-the-S shear sense is obtained. This result is in striking agreement with the convergence direction between Africa and W-Europe/Iberia during Eocene, computed from the North Atlantic magnetic anomalies. Our geodynamic reconstruction, combined with structural and petrological evidence, allows to relate the Curinga-Girifalco mylonites to a thrust related to the southeastern front of the double-verging Alpine chain. The adopted method could be used also for other exotic terranes, such as the Kabylie or the Corsica-Sardinia, to better constrain geometry and evolution of the southern Alpine belt.

Patterns of plant traits in Pyrenean alpine vegetation

Here we studied the adaptation of plant communities to environment in the alpine belt of the Catalan Pyrenees through comparative analysis of plant traits. The starting point consisted of about 800 phytocoenological relevés from the Banc de Dades de Biodiversitat de Catalunya, which corresponded to 47 communities (associations and subassociations) and included 683 taxa. Eleven attributes were examined in each community. Some of these traits are directly referred to the community level (averages of cover, species richness or diversity of life forms) and others to species level, but expressed as the relative cover in the communities (percentages of life forms, succulence, evergreeness, woodiness, lateral spread ability, dissemination type). Alpine landscape is mainly made up of hemicryptophytes, of which graminoids dominate in terms of cover and non-graminoids in species number. Strong persistence via plurennial stocks or dense turfs, entire above-ground renewal over winter, lateral spreading over short distances and generalistic diaspore dissemination complete the main attributes of the High Pyrenees and most alpine floras. Nevertheless, considerable percentages of particular plant types (like therophytes, various kinds of chamaephytes, succulents, evergreens and berry-producers) give a highly diversified alpine belt. On the basis of the attributes, we performed a fuzzy multivariate classification of plant communities, which gave seven main vegetation groups, and five subgroups in the largest category (pastures). Most of the groups coincided with high-level syntaxa (classes, orders) and corresponded to the main habitats of the alpine belt, defined in terms of topography and related soil and microclimate descriptors. With respect to the spectrum of attributes of the whole alpine flora, the most differentiated groups of communities corresponded to several main habitats, all of which associated with stress conditions (scarcity of soil, unfertile or waterlogged substrata). These plant communities tend to be species-poor and show relatively high percentages of particular types. Groups less differentiated from the global spectrum included mainly richer communities with more shared dominances, and correspond to more balanced environments.

UPPER CRETACEOUS PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY OF THE BEY DAGLARI AUTOCHTHON IN THE KORKUTELI AREA, WESTERN TAURIDES, TURKEY

The Upper Cretaceous sequence of the Korkuteli area (Western Taurides) comprises two formations. The Bey Daglari Formation lies at the base and can be divided into two parts. A 600-m-thick neritic lower part is capped with thin, massive, hemipelagic limestones. The Akdag Formation disconformably overlies different stratigraphic levels of the Bey Daglari Formation along a prominent erosional surface and consists of thin-bedded, cherty, pelagic, clayey limestones. Paleogene marls form the base of the Tertiary sequence and disconformably overlie different stratigraphic levels of the Upper Cretaceous succession. This study identifies from thin sections and analyzes the Late Cretaceous planktonic foraminifera. Identification of forty-five species belonging to the genera Contusotruncana , Dicarinella, Gansserina , Globotruncana , Globotruncanella , Globotruncanita, Marginotruncana and Radotruncana has led to the recognition of five biostratigraphic zones, in ascending order: Dicarinella concavata Interval Zone (IZ), Dicarinella asymetrica Total Range Zone (TRZ), Radotruncana calcarata TRZ, Globotruncana falsostuarti Partial Range Zone (PRZ) and Gansserina gansseri IZ, from the Senonian succession of the Bey Daglari autochthon. The Dicarinella concavata IZ and Dicarinella asymetrica TRZ have been identified from the massive hemipelagic limestones of the Bey Daglari Formation and indicate a Coniacian-Santonian age. The Radotruncana calcarata TRZ, Globotruncana falsostuarti PRZ and Gansserina gansseri IZ have been recognized from the pelagic limestones of the Akdag Formation and suggest a late Campanian-early Maastrichtian age. The identified planktonic foraminiferal biozones indicate that the Bey Daglari carbonate platform drowned after the late Turonian; the Upper Cretaceous (Coniacian-early Maastrichtian) pelagic succession includes two stratigraphic gaps in the Korkuteli area corresponding to lower-middle Campanian and upper Maastrichtian. Slight drowning of the platform after the late Turonian may have been related to the regional extension which affected peri-Mediterranean alpine belts. The regional hiatuses in the pelagic succession are also ascribed to the tectonic events, as the Late Cretaceous is a time of great tectonic activity in this critical area of Tethys. Eustatic sea-level changes may have had a secondary effect on the Upper Cretaceous carbonate succession of the Bey Daglari autochthon.

Germination Responses to GA3 and Stratification of Threatened Festuca L. Species from Eastern Mediterranean

The seed germination characteristics of three threatened Festuca sp. [F. punctoria Sm., F. cyllenica Boiss. et Heldr. subsp. uluana Markgr.-Dannenb., F. paphlagonica (St.-Yves) Markgr.-Dannenb. subsp. paphlagonica] were investigated. These species are endemic and spread on alpine belt. The study was carried out with wet-cold and dry-cold stratification throughout 15 days, different doses of GA3 (50, 100 and 150 ppm) and hormone-stratification combined treatments, and non-treatment series. We found that the germination rates of three fescue seeds for various treatment series were different. The mean germination percentage of F. cyllenica was higher (80%) than that of F. punctoria and F. paphlagonica which were fairly low (50-60%). Germination rates increased by wet-stratification treatment in F. punctoria and also increased with 100 ppm GA3 application to the seeds of F. paphlagonica. When taken into consideration the germination percentages of all fescue species, the seeds of F. punctoria and F. paphlagonica can be dormant, but the seeds of F. cyllenica are non-dormant.

La végétation des sols polygonaux aux étages alpin supérieur et subnival en Valais (Alpes centro-occidentales, Suisse)

Beguin Cl., Progin Sonney M. and Vonlanthen M. 2006. The vegetation of polygonal soils at the upper alpine and subnival belts in Switzerland. Bot. Helv. 116: 41–54. Polygonal soils are typical formations of arctic regions but occur locally at high elevation in the Alps. A vegetation survey of sites with polygonal patterning of soils in the Western Swiss Alps revealed a clear distinction between (1) periglacial polygonal soils, whose structure is created by frost action, and whose occurrence is limited to the subniveal belt (2700–3000 m a.s.l.) and (2) soils whose polygonal structures are mere contraction cracks created by desiccation, which are found in the alpine belt (2300–2750 m a.s.l). Two new plant associations characteristic of these sites are described: periglacial polygonal soils of the subniveal belt are colonized by the association Saxifrago oppositifoliae- Poetum alpinae ass. nov. of the alliance Drabion hoppeanae. Conversely, soils with polygonal contraction cracks shelter the association Epilobio anagallidifolii- Saginetum saginoidis ass. nov., which is related to the alliance Salicion herbaceae. We describe the particular geomorphological and climatic factors leading to the local formation of these soil types with their specialised vegetation. We conclude that their future existence is strongly threatened by climate warming.

End Cretaceous to recent polyphased compressive tectonics along the “Môle Constantinois” and foreland (NE Algeria)

The “Môle Constantinois” units and their forelands are part of the Alpine Belt of northeastern Algeria. From the North to the South they correspond to the following three tectonic domains: (i) the “Môle Constantinois” thrust unit; (ii) the Pre-Atlas domain corresponding to the folded and/or sliced belt and the Pre-Atlas corridor slightly affected by tectonics; and southwards, (iii) the folded and faulted autochthonous foreland represented mainly by the Aurès massif. This Belt is the result of a series of short-lived compressional deformations that we summarize in this paper and which occurred successively during the end Cretaceous, the Early-Late Eocene, around the Aquitanian–Burdigalian transition, during the Tortonian, and during the Early Pleistocene. Structural, stratigraphic and micro-tectonic arguments have been used to describe this polyphased event during a compressional tectonic history throughout the different domains. These tectonic events can also be identified in the neighbouring areas of the Maghrebides Alpine Belt and correspond to the major stages of inversion of the African Tethyan margin. However this tectonics is not homogeneous throughout the entire Maghrebides Belt, as paleo-stress fields and age of major deformations may vary from a region to another.

Evolution of Asian ‘lowland’ taxa in relation to the Alpine–Himalayan Tertiary orogenic belt – Insight from a cladistic analysis of Maladera ( Cycloserica) (Coleoptera: Scarabaeidae: Sericini)

Among the south Asian Sericini only a very few endemic monophyletic lineages developed in the lowland areas, such as the taxa belonging to Maladera (subgenus Cycloserica). Twenty species of Sericini (Coleoptera: Scarabaeidae) representing the principal lineages of Maladera occurring in the Palearctic region were included in a parsimony analysis based on 37 morphological characters. Maladera ( Cycloserica) was found be monophyletic, composed by a clade comprising ( Maladera caspia ( Cycloserica excisipes, Leucoserica arenicola)) being distributed in the Middle Asian lowlands and its sister group the Maladera quinquidens-group with four endemic species in the Himalayan and North Indian lowlands. The ranges of these two clades as well as of the sister group of Cycloserica reveal a separating effect by the uplifted Himalayan–Alpine belt. It is hypothesized that these two Cycloserica lineages existed before they dispersed into the two separated areas, the northern Indian subcontinent (Himalayas) and the Middle Asian lowland. Due to the sister group relationship of Cycloserica and Leucoserica, both nested deeply within the species of Maladera, it seems reasonable to consider both synonymous with Maladera. Based on this conclusion one new combination is necessary, Maladera ( Cycloserica) arenicola, and Leucoserica Reitter, 1896, is placed in synonymy with Cycloserica Reitter, 1896).