Southwestern Alps Research Articles

Leiobunum religiosum: neu für Deutschland (Arachnida: Opiliones)

Leiobunum religiosum (Arachnida: Opiliones): first record for Germany. L. religiosum Simon, 1879 was found at Mayen near Koblenz (Rhineland-Palatinate), Germany. This is the first record for Germany and is about 500 km from the known distribution area of the species in the southwestern Alps. The German population seems to be restricted to the ancient Roman quarry Mayener Grubenfeld where it is confined to stone walls and cave systems with balanced microclimatic conditions. Genital morphological structures were found to be very fragile, were easily deformed and therefore apparently variable. Difficulties in using these characters for taxonomy are discussed. Ecology, provenance and conservation status of the newly discovered popula- tion are considered.

Lateglacial and Holocene climate oscillations in the South-western Alps: An attempt at quantitative reconstruction

The high topographic complexity of the Alpine region is the origin of important climate differences that characterise the different areas of the Alps. These differences might have had a strong influence on vegetation and on migrations of human populations in the past. Based on an improved database containing about 3000 modern pollen samples, the standard “Modern Analogue Technique” has been applied to five pollen sequences from the subalpine belt of the South-western Italian Alps (Laghi dell’Orgials, 2240 m, Lago delle Fate, 2130 m, Torbiera del Biecai, 1920 m, Rifugio Mondovì, 1760 m, Pian Marchisio, 1624 m) to provide quantitative climate estimates for the Lateglacial and Holocene periods. Consistent climate trends are reconstructed for the different sequences. Sites recorded in detail the climate variations when they were located at the limit of two ecotones. Sites above the tree line recorded lower temperature values and less important variations. Climate was cold and dry during the Oldest and Younger Dryas and close to present-day values during the Bølling/Allerød interstadial. At the beginning of the Holocene, climate changed to warmer and moister conditions; a high number of climate fluctuations are recorded at several sites. A climate optimum is recorded in the Atlantic period, which caused a development of fir above its present-day altitudinal distribution. Climatic differences recorded at the various sites are discussed taking into account the limits of the method.

The genetic structure of the mountain forest butterfly Erebia euryale unravels the late Pleistocene and postglacial history of the mountain coniferous forest biome in Europe

The distribution of the mountain coniferous forest biome in Europe throughout time is not sufficiently understood. One character species of this habitat type is the large ringlet, Erebia euryale well reflecting the extension of this biome today, and the genetic differentiation of this species among and within mountain systems may unravel the late Pleistocene history of this habitat type. We therefore analysed the allozyme pattern of 381 E. euryale individuals from 11 populations in four different European mountain systems (Pyrenees, Alps, Carpathians, Rila). All loci analysed were polymorphic. The mean F(ST) over all samples was high (20%). Furthermore, the mean genetic distance among samples was quite high (0.049). We found four different groups well supported by cluster analyses, bootstraps and hierarchical variance analyses: Pyrenees, western Alps, eastern Alps and southeastern Europe (Carpathians and Rila). The genetic diversity of the populations was highest in the southeastern European group and stepwise decreased westwards. Interestingly, the populations from Bulgaria and Romania were almost identical; therefore, we assume that they were not separated by the Danube Valley, at least during the last ice age. On the contrary, the differentiation among the three western Alps populations was considerable. For all these reasons, we assume that (i) the most important refugial area for the coniferous mountain forest biome in Europe has been located in southeastern Europe including at least parts of the Carpathians and the Bulgarian mountains; (ii) important refugial areas for this biome existed at the southeastern edge of the Alps; (iii) fragments of this habitat types survived along the southwestern Alps, but in a more scattered distribution; and (iv) relatively small relicts have persisted somewhere at the foothills of the Pyrenees.

Morphological and Geographical Evidence are Misleading with Respect to the Phylogenetic Position and Origin of the Narrow Endemic Polyploid <I>Androsace cantabrica</I> (Primulaceae)

Allopolyploidy is recognized as an important mode of plant speciation. The allopolyploid origin of a taxon is often inferred from morphological intermediacy or a mixture of morphological characters from the putative parental taxa, especially if accompanied by geographical intermediacy of the polyploid. Here we show that in the case of Androsace cantabrica (Primulaceae), a narrow endemic from the central Cordillera Cantabrica (Spain), both lines of evidence are misleading. Instead of being an allopolyploid derivative of A. halleri (western Cordillera Cantabrica, eastern Pyrenees, Massif Central, Vosges) and A. laggeri (central Pyrenees), A. cantabrica is most likely an autopolyploid closely related to A. adfinis s. 1., endemic to the southwestern European Alps. This counterintuitive biogeographic connection not only adds to the group of species showing a Cantabrian-Alpine disjunction, but, together with the unexpected link between A. chaixii, also from the southwestern Alps, and A. halleri in form of the northern Spanish local endemic A. rioxana, underlines the important role of large-scale range shifts in shaping the current distribution of European mountain taxa.

Late-glacial chironomid-based temperature reconstructions for Lago Piccolo di Avigliana in the southwestern Alps (Italy)

Chironomid headcapsules were used to reconstruct late glacial and early-Holocene summer temperatures at Lago Piccolo di Avigliana (LPA). Two training sets (northern Sweden, North America) were used to infer temperatures. The reconstructed patterns of temperature change agreed well with the GRIP and NGRIP δ 18O records. Inferred temperatures were high during the Bølling (ca 19 °C), slowly decreased to ca 17.5 °C during the Allerød, reached lowest temperatures (ca 16 °C) during the Younger Dryas, and increased to ca. 18.5 °C during the Preboreal. The amplitudes of change at climate transitions (i.e. Oldest Dryas/Bølling: 3 °C, Allerød/Younger Dryas: 1.5 °C, and Younger Dryas/Preboreal: 2.5 °C) were smaller than in the northern Alps but similar to those recorded at another site in northeastern Italy. Our results suggest that (1) Allerød temperatures were higher in the southern Alps and (2) higher during the Preboreal (1 °C) than during the Allerød. These differences might provide an explanation for the different responses of terrestrial-vegetation to late glacial and early-Holocene climatic changes in the two regions. Other sites on both sides of the Alps should be studied to confirm these two hypotheses.

Genetic Differentiation among Populations of Cicerbita alpina (L.) Wallroth (Asteraceae) in the Western Alps

In this study we analyzed the genetic population structure of the hygrophilous tall-herb Cicerbita alpina in the western Alps because this group of mountain plants is underrepresented in the biogeographical literature. AFLP (amplified fragment length polymorphism) fingerprints of 40 samples were analyzed from four populations situated in a transect from the southwestern Alps to the eastern part of the western Alps and one population from the Black Forest outside the Alps. Two genetic groups can be distinguished. The first group (A) comprises the populations from the northern and eastern parts of the western Alps, and the second group (B) comprises the populations from the southwestern Alps and the Black Forest. Group A originates most likely from at least one refugium in the southern piedmont regions of the Alps. This result provides molecular evidence for a humid climate at the southern margin of the Alps during the Würm glaciation. Group B originates presumably from western or northern direction and we discuss two possible scenarios for the colonization of the Alps, i.e. (1) long-distance dispersal from southwestern refugia and (2) colonization from nearby refugia in the western and/or northern Alpine forelands. The study demonstrates that the target species harbours considerable genetic diversity, even on a regional scale, and therefore is a suitable model for phylogeographic research.

Cryptic differentiation in alpine‐endemic, high‐altitude butterflies reveals down‐slope glacial refugia

The influence of cyclic climate fluctuations and their impact on high-altitude species is still insufficiently understood. We therefore analysed in this study the genetic structure of cold-adapted animals and their coherence with geographical distributions throughout the Late Quaternary. We analysed 588 individuals from 23 populations of the alpine-endemic lesser mountain ringlet, Erebia melampus, by allozyme electrophoresis to detect its intraspecific differentiation. As an outgroup, we added one population of Erebia sudetica inalpina from Grindelwald (Swiss Alps). Seventeen of 18 loci were polymorphic. The mean F(ST) over all samples was 37%. We detected strong differentiation into three lineages with the genetic distances between the two E. melampus groups being larger than between each of the two E. melampus groups and E. sudetica. The mean genetic distance among these three groups was 0.17. These results give evidence for the existence of a species complex within the E. melampus/sudetica group and indicate a discontinuous distribution within this group during at least the last ice age. One of them, E. sudetica inalpina, is found in the northern Alps and most probably had its Würm glacial refugium north of the glaciated Alps. The western E. melampus group might have had a refugium at the southwestern Alps margin, the eastern group in the lower altitudes of the southeastern and/or eastern Alps. In the latter, a further subdivision within this relict area is possible.

Are there really superposed Mohos in the southwestern Alps? New seismic data from fan-profiling reflections

SUMMARY The Moho preserves imprints of the regional geodynamic evolution of the lithosphere. As such, its detailed topography in divergence or convergence zones has a strong bearing on any geodynamic model. This is still more critical where 3-D effects are expected, as in the case of the Alpine chain which exhibits in its western part a short radius of curvature while its trend rotates by 180°. The deep structure of this zone, characterized by a peculiar imbrication of high-density material of lower crust or mantle origin, remains a puzzle. In September 1999, a new controlled-source-seismology experiment was carried out in the southwestern Alps, in the area between the Pelvoux, Dora Maira and Argentera massifs. Five shots were recorded with 130 seismic stations deployed on a total of nine fan- and one in-line profiles. It aimed at getting information on the Moho depth in a hitherto blank area, and discussing the existence of the hypothetical Brianconnais mantle flake mapped in 1986 by the ECORS-CROP experiment. Fan profiles recorded at critical distance for reflections from the European Moho allowed us to map in detail the thickening of the crust from the Mediterranean coastline (27 km) to the root zone (55 km). The zone just south of the Pelvoux massif is characterized by a rather flat, 40-km-deep Moho, which distorts the isobaths in thickening the crust along the Durance valley. Beneath the Argentera massif and just north of it, we evidence a strong dip of the Moho down to 51 km, whereas previous maps predicted depths of 40–46 km only. A new, detailed map of the European Moho can be drawn, which integrates depth data measured at ∼300 reflection midpoints. However, the experiment could not establish the continuity of the Brianconnais mantle flake over a large area in the internal Alps. We observed several reflectors in the 15–31-km depth range. One of them is the Ubaye reflector, a 20-km-long, 23–31-km-deep structure. It might correspond to the Brianconnais mantle flake, although it is located much farther south than the reflector mapped in 1986. New investigations will be necessary to state whether its origin is crustal or due to wedging of mantle material.

Phylogeography of the endangered Eryngium alpinum L. (Apiaceae) in the European Alps

We studied the phylogeography of Eryngium alpinum by sequencing two intergenic chloroplast spacers, trnH-psbA and trnS-trnG (1322 bp). The sampling design included 36 populations and 397 individuals spanning the entire distribution range of the species, from France to Bosnia. Twenty-one haplotypes were characterized and polymorphism was observed both within and among populations. Population differentiation was strong (F(ST) = 0.92) and largely explained by the distinction of five geographic regions: Southwestern, Western, Middle, Eastern Alps and Balkans (F(CT) = 0.62). Moreover, N(ST) was significantly higher than G(ST) (P < 0.05), showing the existence of a phylogeographic pattern. Six major lineages were recognized using samova and median-joining networks. One lineage, highly divergent from the other ones, was only found in the Balkans and probably persisted in situ during last glaciations. All other lineages might have survived in a Southwestern refugium (Mercantour) and colonized the entire Alpine arc (Southwestern, Western, Middle and Eastern Alps) through repeated colonization events at different time periods. This is the first empirical study suggesting Southern refugia for calcareous Alpine plants, although the existence of a secondary refugium in northern Italy/Austria is also suspected. We also observed recent haplotype diversification, especially in the Southwestern Alps.

Local tomography and focal mechanisms in the south-western Alps: Comparison of methods and tectonic implications

We investigate how focal solutions and hypocenter locations may depend on the ray tracing algorithm and the strategy of velocity inversion. Using arrival times from a temporary seismological network in the south-western Alps, a local earthquake tomography has been performed by Paul et al. [Paul, A., Cattaneo, M., Thouvenot, F., Spallarossa, D., Béthoux, N., and Fréchet, J., 2001. A three-dimensional crustal velocity model of the south-western Alps from local earthquake tomography. J. Geophys. Res. 106, 19367–19390.] with the method developed by Thurber [Thurber, C.H., 1993. Local earthquake tomography: velocity and Vp/Vs-Theory, in Seismic Tomography: Theory and practice, Iyer, H.M., and Irahara eds., Chapman and Hall, New York, 563–583.]. Another inversion of the same data set is performed here using a different tomography code relying on a shooting paraxial method and cubic interpolation of velocities. The resulting images display the same main features, although Thurber's code appears to be more robust in regions with scarce ray coverage and strong velocity contrasts. Concerning hypocenter location in Piemont units, one major result is the concentration of hypocenters at the boundary between the mantle wedge of the Ivrea body and the European crust. Forty-six focal mechanisms are shown that were computed using both the take-off angles in the minimum 1-D model and in the 3-D velocity structures resulting from the two inversions. The sets of focal solutions are very similar, proving the reliability and the coherency of the focal solutions. The widespread extension in the core of the western Alps is confirmed whereas a few compressive solutions are found east of the Piemont units. These results constrain the sharp change of stress tensor and evidence a decoupling of strain beneath the east of Dora Maira massif up to beneath the north of Argentera massif. On a geodynamical point of view seismicity and focal mechanism distribution are compatible with the present day models published for the western Alps, where the major feature is the lithospheric thickening [Schmid, S.M., and Kissling, E., 2000. The arc of the western Alps in the light of geophysical data on deep crustal structure. Tectonics, 19, 62–85.], implying widespread extension in the core of the western Alps [Sue, C., Thouvenot, F., Fréchet, J., and Tricart, P., 1999. Widespread extension in the core of the western Alps revealed by earthquake analysis. J. Geophys. Res., 104, 25611–25622.]. However the existence of compressive events dealing at depth with the boundary of Ivrea body allows to postulate that this geological structure is still tectonically active. Even if field work has not shown this so far, the Insubric line appears to extend toward the south at depth, as a blind fault, and to play a key role in the dynamics of the south-western Alps.

Molecular biogeography of Europe: Pleistocene cycles and postglacial trends

The climatic cycles with subsequent glacial and intergalcial periods have had a great impact on the distribution and evolution of species. Using genetic analytical tools considerably increased our understanding of these processes. In this review I therefore give an overview of the molecular biogeography of Europe. For means of simplification, I distinguish between three major biogeographical entities: (i) "Mediterranean" with Mediterranean differentiation and dispersal centres, (ii) "Continental" with extra-Mediterranean centres and (iii) "Alpine" and/or "Arctic" with recent alpine and/or arctic distribution patterns. These different molecular biogeographical patterns are presented using actual examples.Many "Mediterranean" species are differentiated into three major European genetic lineages, which are due to glacial isolation in the three major Mediterranean peninsulas. Postglacial expansion in this group of species is mostly influenced by the barriers of the Pyrenees and the Alps with four resulting main patterns of postglacial range expansions. However, some cases are known with less than one genetic lineage per Mediterranean peninsula on the one hand, and others with a considerable genetic substructure within each of the Mediterranean peninsulas, Asia Minor and the Maghreb. These structures within the Mediterranean sub-centres are often rather strong and in several cases even predate the Pleistocene.For the "Continental" species, it could be shown that the formerly supposed postglacial spread from eastern Palearctic expansion centres is mostly not applicable. Quite the contrary, most of these species apparently had extra-Mediterranean centres of survival in Europe with special importance of the perialpine regions, the Carpathian Basin and parts of the Balkan Peninsula. In the group of "Alpine" and/or "Arctic" species, several molecular biogeographical patterns have been found, which support and improve the postulates based on distribution patterns and pollen records. Thus, genetic studies support the strong linkage between southwestern Alps and Pyrenees, northeastern Alps and Carpathians as well as southeastern Alps and the Dinaric mountain systems, hereby allowing conclusions on the glacial distribution patterns of these species. Furthermore, genetic analyses of arctic-alpine disjunct species support their broad distribution in the periglacial areas at least during the last glacial period.The detailed understanding of the different phylogeographical structures is essential for the management of the different evolutionary significant units of species and the conservation of their entire genetic diversity. Furthermore, the distribution of genetic diversity due to biogeographical reasons helps understanding the differing regional vulnerabilities of extant populations.

Long‐distance dispersal vs vicariance: the origin and genetic diversity of alpine plants in the Spanish Sierra Nevada

Here, we investigated the origin and genetic diversity of four alpine plant species co-occurring in the Spanish Sierra Nevada and other high mountains in south-western Europe by analysis of amplified fragment length polymorphisms (AFLPs). In Kernera saxatilis, Silene rupestris and Gentiana alpina we found intraspecific phylogroups corresponding to mountain regions as predicted by the vicariance hypothesis. Moreover, genetic distances between Sierra Nevada and Pyrenees populations were always higher than those between populations from the Pyrenees and the south-western Alps/Massif Central. This suggests successive disruption of gene exchange between mountain ranges as postglacial climatic warming proceeded from south to north. In Papaver alpinum, our data indicate that a central Pyrenean population arose via long-distance dispersal from the Sierra Nevada, and that vicariant separation events between the Sierra Nevada and the Pyrenees and between the Pyrenees and the south-western Alps occurred simultaneously. Overall, Sierra Nevada populations of all species investigated here preserve unexpectedly high (or not exceptionally reduced) genetic diversity. This testifies to the important influence of long-term isolation, i.e. vicariance, on genetic diversity through fostering the accumulation of new mutations and/or the fixation of ancestral ones.

Dynamics of the MAP IOP 15 severe Mistral event: Observations and high‐resolution numerical simulations

AbstractThis paper investigates the fundamental processes involved in a severe Mistral event that occurred during the Mesoscale Alpine Program (from 6 to 9 November 1999). The Mistral refers to a violent north/north‐westerly wind blowing in south‐eastern France from the Rhône valley to the French Riviera. The study is based on measurements from radiosoundings launched from Lyon and Nîmes and from two UHF wind profilers located near Marseille and Toulon allowing a good description of the flow in the complex terrain formed by the southwestern Alps. Observational results are compared with RAMS non‐hydrostatic numerical simulations performed with 27 km, 9 km and 3 km nested grids. The numerical simulations capture the flow complexity both upstream of the Alps and in the coastal area affected by the Mistral. They correctly reproduce horizontal wind speeds and directions, vertical velocities, virtual potential temperature and relative humidity documented by the observational network. The simulations are used to point out the main dynamical processes generating the Mistral. It is found that flow splitting around the Alps and around the isolated peaks bordering the south‐eastern part of the Rhône valley (Mont Ventoux 1909 m, Massif du Lubéron 1425 m) induces the low‐level jet observed near Marseille that lasts for 36 hours. The high‐resolution simulation indicates that the transient low‐level jet lasting for only 9 hours observed at Toulon is due to a gravity wave breaking over local topography (the Sainte Baume 1147 m) where hydraulic jumps are involved. A mountain wake with two opposite‐sign potential‐vorticity banners is generated. The mesoscale wake explains the westward progression of the large‐scale Alpine wake. Copyright © 2006 Royal Meteorological Society.

Holocene vegetation and land‐use changes in response to climatic changes in the forelands of the southwestern Alps, Italy

AbstractThe Holocene sediment of Lago Piccolo di Avigliana (Piedmont, Italy, 356 m a.s.l.) was dated by 14C and analysed for pollen to reconstruct the vegetation history of the area. The early‐ and mid‐Holocene pollen record shows environmental responses to centennial‐scale climatic changes as evidenced by independent palaeoclimatic proxies. When human impact was low or negligible, continental mixed‐oak forests decreased at ca. 9300 BC in response to the early‐Holocene Preboreal climatic oscillation. Abies alba expanded in two phases, probably in response to higher moisture availability at ca. 6000 and ca. 4000 BC, while Fagus expanded later, possibly in response to a climatic change at 3300 BC.During and after the Bronze Age five distinct phases of intensified land use were detected. The near synchroneity with the land‐use phases detected in wetter regions in northern and southern Switzerland points to a common forcing factor in spite of cultural differences. Increasing minerogenic input to the lake since 1000 BC coincided with Late Bronze—Iron Age technical innovations and probably indicate soil erosion as a consequence of deforestation in the lake catchment. The highest values for cultural indicators occurred at 700–450 and at 300–50 BC, coinciding with periods of high solar activity (inferred from Δ14C). This suggests that Iron Age land use was enhanced by high solar activity, while re‐occupation of partly abandoned areas after crises in earlier periods match better with the GRIP stable isotope record. On the basis of our data and comparison with independent palaeoclimatic proxies we suggest that precipitation variation was much more important than temperature oscillations in driving vegetation and societal changes throughout the Holocene. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Pure theory or useful tool?

The article reflects the theoretical concept of transdisciplinarity by presenting the successive work stages of a research project conducted in the Piedmont Alps from 1998 to 2004. It demonstrates why and how transdisciplinary methodology was applied, and the experiences gained from its use. The transdisciplinary strategy was adopted since it enables researchers to cross disciplinary borders and to deal with extra-scientific “real world problems”. The Piedmont Project, therefore, focussed on the expected solutions to the undesired negative ecological and social effects of land abandonment in the south-western Alps. The problem-solving strategy has been divided into five steps: problem definition, problem comprehension, problem analysis, treatment of sub areas and their integration in order to achieve overlapping results. The end of the research was marked by the development and implementation of applicable solutions. Experiences with transdisciplinarity were both negative and positive in nature. On the one hand, the necessity of including the local population was a particularly significant and exhausting challenge, requiring a great deal of openness, patience and communication skills. On the other hand, the ‘real world’ research did bring forth a great amount of practical and theoretical knowledge for the researchers as well as for the stakeholders.

Disjunct distributions during glacial and interglacial periods in mountain butterflies: Erebia epiphron as an example

Over several decades, the distribution patterns and evolution of alpine disjunct species has become an increasingly discussed subject. Large scale genetic analysis has allowed the resolution of the past range changes and intraspecific evolution of many species, in Europe especially of Mediterranean origin. However, the phylogeographic structures of species with arctic-alpine disjunct distribution patterns are relatively poorly studied. The existing phylogeographic analysis (mostly of alpine plant species) supports disjunct distributions during glacial as well as post-glacial periods for a number of species. However, several questions still remain unresolved and we therefore analysed the Mountain Ringlet Erebia epiphron as a model for such alpine disjunct species. We found strong differentiation into five different lineages supporting five differentiation centres: (i) the eastern Pyrenees, (ii) the mountain ranges between the central Pyrenees and south-western Alps, (iii, iv) two areas along the southern Alps margin and (v) the northern Alps margin. We propose that these patterns evolved due to the humidity requirements of this species, which did not allow survival in the dry glacial steppes, but along the margins of the wetter glaciated high mountain ranges.

Permafrost existence in rock glaciers of the Argentera Massif, Maritime Alps, Italy

AbstractThermal and geo‐electrical investigations were carried out on five rock glaciers in the Argentera Massif to detect the presence of permafrost and to define its existence and activity elevation limits. Ground surface temperature was monitored using digital dataloggers, and sub‐surface ice occurrence was inferred from one‐dimensional geo‐electrical soundings. Bottom temperatures of snow cover, extracted from winter recordings, indicate possible or probable presence of permafrost for some rock glaciers. Geo‐electrical soundings reveal the existence of sediments rich and super‐saturated with ice for thicknesses often reaching several tens of metres. The limits for permafrost existence and for rock glacier activity can thus be fixed respectively at about 2500 m and 2600 m ASL. The results from 110 earlier geo‐electrical soundings, carried out on rock glaciers in different sectors of the southwestern Alps, were processed and compared with the results of this work. A general classification of rock glaciers into active, inactive and relict was possible for the Argentera Massif. Inactive and relict rock glaciers probably originated during colder Holocene and Late‐glacial periods. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Consistent Shifts in Alpine Plant Traits along a Mesotopographical Gradient

Despite an increasing interest in the study of functional diversity, there have been few attempts to link plant traits, habitat variation, and community structure in Alpine landscapes. These interrelationships were examined along a snowmelt and growing-season-length gradient determined by mesotopographical variations. The study site was chosen so as to encompass much of the floristic beta diversity encountered at the Alpine belt of the southwestern Alps. A three-table ordination technique, named RLQ, was used to unravel on a quantitative basis the co-structure of a plot-by-environmental-variable table, a plot-by-species table, and a species-by-traits table. The main covariations between traits and habitat were (1) an increased specific leaf area (SLA) and leaf nitrogen content on a mass basis (N mass) in late-meting sites, (2) a trend toward upright and thick leaves in the most exposed, physically disturbed, early-melting sites, and (3) an increasing leaf area in the middle of the gradient, which also exhibits small-scale disturbance due to the Alpine marmot. The interplay of intermediate snow-melting dates and intense zoogenic disturbance appears to promote plant diversity and the persistence of species whose mean-elevation distribution is located much below the study site. The adaptive value of trait attributes along the mesotopographical gradient is discussed within the broader context of plant strategies in temperate Alpine grasslands.

Improving automatic location procedure by waveform similarity analysis: An application in the South Western Alps (Italy)

The accuracy of automatic procedures for locating earthquakes is influenced by several factors such as errors in picking seismic phases, network geometry, modeling errors and velocity model uncertainties. The main purpose of this work is to improve the performances of the automatic procedure employed for the “quasi-real-time” location of seismic events in North Western Italy by developing a procedure based on a waveform similarity analysis and by using only one seismic station. To detect “earthquake families” a cross-correlation technique was applied to a data set of seismic waveforms recorded in the period 1985–2002, in a small test area (1600 km 2) located in the South Western Alps (Italy). Normalized cross-correlation matrices were calculated using about 2700 seismic events, selected on the basis of the signal to noise ratio, manually picked and located by using the Hypoellipse code. The waveform similarity analysis, based on the bridging technique, allowed grouping about 65% of the selected events into 80 earthquake families (multiplets) located inside the area considered. For each earthquake family a master event is selected, manually re-picked and re-located by using Hypoellipse code. Having chosen a reference station (STV) on the basis of the completeness of the available data set, an automatic procedure has been developed with the aim of cross-correlating new seismic recordings (automatically picked) to the waveforms of the events belonging to the detected families. If the new event is proved to belong to a family (on the basis of the cross-correlation values), its hypocenter co-ordinates are defined by the location of the master event of the associated family. The performance of the proposed procedure is tested and demonstrated using a data set of 104 selected earthquakes recorded in the period January 2003–June 2004 and located in the test area. The automatic procedure is able to locate, associating events with the multiplets detected by the waveform similarity analysis, about 50% of the test events, almost independently of the accuracy of the automatic phase picker and without the biasing of the network geometry and of the velocity model uncertainties.

“Wilderness”: what it means when it becomes a reality—a case study from the southwestern Alps

Within the framework of the transdisciplinary research project “Changes in alpine landscapes resulting from a decline in land use in the Val Grande National Park and Strona Valley—from rural landscape to wilderness”, the impacts of uncontrolled nature development on the landscape’s structural diversity, plant species richness, as well as on the local population and tourists were investigated. The study area was the community of Premosello Chiovenda in the Val Grande National Park—“Italy’s largest wilderness area”. In order to achieve reliable results, methods for conducting historical landscape analysis, ecological inventories and empirical–social research were combined. As a result of land abandonment, the floristic species richness is decreasing in higher successional stages, and depending on the altitude, the structural diversity of the landscape is changing. Wildfires in the successional communities pose threats to the neighbouring villages. Nevertheless, many rural and cultural landscape characteristics persist, and past uses continue to have a significant impact on future landscape development. The main impacts on the inhabitants are psychological and economic in nature. Around the villages, they regard the effects of abandonment in a very negative light. Visitors of the area judge the consequences of land abandonment differently. While they regard the resulting landscape’s wildness positively, they also regret the cultural losses suffered by rural communities. If the abandoning processes continue, rural landscape and its associated habitats will be lost. Despite this, new habitats, such as those resulting from ecosystem dynamics, will form. The evolving landscape is not, however, hospitable as a living space for man. The characteristics intrinsic to the landscape in the absence of its productive use and maintenance render it uninhabitable. A reasonable scenario for Premosello Chiovenda should provide the coexistence of dynamic, “wild” areas, free from further agri- or silvicultural uses and areas of cultural importance, where traditional and innovative forms of land use should be encouraged and developed. In the future, decision-makers should be aware of the positive and negative aspects of a large-scale rewilding, and all stakeholders, especially the affected local communities, should be included in any decision making process that concerns the establishment of protected areas which are left to develop without human control.