Calcareous Bedrock Research Articles

Organic matter losses in German Alps forest soils since the 1970s most likely caused by warming

Climate warming is expected to induce soil organic carbon losses in mountain soils that result, in turn, in reduced soil fertility, reduced water storage capacity and positive feedback on climate change. Here we combine two independent sets of measurements of soil organic carbon from forest soils in the German Alps—repeated measurements from 1976 to 2010 and from 1987 to 2011—to show that warming has caused a 14% decline in topsoil organic carbon stocks. The decreases in soil carbon occurred over a period of significant increases in six-month summer temperatures, with the most substantial decreases occurring at sites with large changes in mean annual temperature. Organic carbon stock decreases were largest—on average 32%—in forest soils with initial topsoil organic carbon stocks greater than 8 kg C m−2, which can be found predominantly on calcareous bedrock. However, organic carbon stocks of forest soils with lower initial carbon stocks, as well as soils under pasture or at elevations above 1,150 m, have not changed significantly. We conclude that warming is the most likely reason for the observed losses of soil organic carbon, but that site, land use and elevation may ameliorate the effects of climate change. Soil carbon concentrations are sensitive to climate warming. Pairs of measurements of forest soil carbon stocks in the German Alps reveal that topsoil carbon concentrations declined as air temperatures rose between 1976 and 2011.

The copper spoil heap Knappenberg, Austria, as a model for metal habitats – Vegetation, substrate and contamination

Historic mining in the Eastern Alps has left us with a legacy of numerous spoil heaps hosting specific, metal tolerant vegetation. Such habitats are characterized by elevated concentrations of toxic elements but also by high irradiation, a poorly developed substrate or extreme pH of the soil. This study investigates the distribution of vascular plants, mosses and lichens on a copper spoil heap on the ore bearing Knappenberg formed by Prebichl Layers and Werfener Schist in Lower Austria. It serves as a model for discriminating between various ecological traits and their effects on vegetation.Five distinct clusters were distinguished: (1) The bare, metal rich Central Spoil Heap was only colonised by highly resistant specialists. (2) The Northern and (3) Southern Peripheries contained less copper; the contrasting vegetation was best explained by the different microclimate. (4) A forest over acidic bedrock hosted a vegetation overlapping with the periphery of the spoil heap. (5) A forest over calcareous bedrock was similar to the spoil heap with regard to pH and humus content but hosted a vegetation differing strongly to all other habitats.Among the multiple toxic elements at the spoil heap, only Cu seems to exert a crucial influence on the vegetation pattern. Besides metal concentrations, irradiation, humidity, humus, pH and grain size distribution are important for the establishment of a metal tolerant vegetation. The difference between the species poor Northern and the diverse Southern Periphery can be explained by the microclimate rather than by the substrate. All plant species penetrating from the forest into the periphery of the spoil heap originate from the acidic but not from the calcareous bedrock.

Thickness of pyroclastic cover beds: the case study of Mount Albino (Campania region, southern Italy)

ABSTRACTThe paper presents a method for estimating and mapping – at detailed scale (1:5000) – the thickness of pyroclastic cover beds resting on calcareous bedrock. This method, tested in the study area of Mount Albino (Campania region, southern Italy), makes use mainly of information gathered from in situ investigations, managed and processed in a geographical information system environment via a geostatistical interpolation technique (i.e. ordinary kriging) and finally integrated and amended by adopting a heuristic approach. Given its easy applicability and affordable costs, the proposed method can be used in similar geological contexts where knowledge of the spatial distribution of pyroclastic cover beds is a requirement for understanding and predicting slope instability processes.

Vascular plant endemism in the Western Carpathians: spatial patterns, environmental correlates and taxon traits

The Western Carpathians, as part of the Carpathian mountain range, are one of the most important centres of vascular plant endemism in Europe. We analysed the distribution patterns of 85 vascular plant taxa (excluding apomictic groups) that are endemic to this region (Western Carpathian endemics) or to the whole Carpathians (pan-Carpathian endemics) across 125 operational geographic units (OGUs) delimited in the area, and assessed their niche and altitudinal breadths, habitat preferences, and life-history traits. Spatial pattern of endemic richness was not random, but was geographically structured with the highest values recorded in the OGUs from the central part of the Western Carpathians. The pan-Carpathian endemics had, on average, larger distributional ranges in the Western Carpathians than the Western Carpathian endemics and showed slightly different distribution patterns, probably affected by historical migrations from the Eastern and Southern Carpathians. A significantly higher proportion of endemics occurred in open non-forest habitats (i.e. rocks/screes and grasslands, 74%) than in forests (18%). Almost 64% of endemic taxa occurred on calcareous bedrock, while only 12% and 21% were confined to siliceous or both types of bedrocks, respectively. We found a strong positive correlation between the distribution range of endemic taxa and altitudinal and niche breadths. There were no differences between diploids and polyploids in any of tested traits, niche and altitudinal breadths and range size. The best linear model explained almost 75% of endemic richness patterns, and included maximal altitude and its interactions with the proportion of calcareous areas and total area of OGUs as the best predictors. Our data suggest that both environmental conditions and historical migrations have shaped the current pattern of endemic richness in the Western Carpathians.

Speciation of phosphorus in temperate zone forest soils as assessed by combined wet‐chemical fractionation and XANES spectroscopy

AbstractPhosphorus availability in terrestrial ecosystems is strongly dependent on soil P speciation. Here we present information on the P speciation of 10 forest soils in Germany developed from different parent materials as assessed by combined wet‐chemical P fractionation and synchrotron‐based X‐ray absorption near‐edge structure (XANES) spectroscopy. Soil P speciation showed clear differences among different parent materials and changed systematically with soil depth. In soils formed from silicate bedrock or loess, Fe‐bound P species (FePO4, organic and inorganic phosphate adsorbed to Fe oxyhydroxides) and Al‐bound P species (AlPO4, organic and inorganic phosphate adsorbed to Al oxyhydroxides, Al‐saturated clay minerals and Al‐saturated soil organic matter) were most dominant. In contrast, the P speciation of soils formed from calcareous bedrock was dominated (40–70% of total P) by Ca‐bound organic P, which most likely primarily is inositol hexakisphosphate (IHP) precipitated as Ca3‐IHP. The second largest portion of total P in all calcareous soils was organic P not bound to Ca, Al, or Fe. The relevance of this P form decreased with soil depth. Additionally, apatite (relevance increasing with depth) and Al‐bound P were present. The most relevant soil properties governing the P speciation of the investigated soils were soil stocks of Fe oxyhydroxides, organic matter, and carbonate. Different types of P speciation in soils on silicate and calcareous parent material suggest different ecosystem P nutrition strategies and biogeochemical P cycling patterns in the respective ecosystems. Our study demonstrates that combined wet‐chemical soil P fractionation and synchrotron‐based XANES spectroscopy provides substantial novel information on the P speciation of forest soils.

The Community Structures of Prokaryotes and Fungi in Mountain Pasture Soils are Highly Correlated and Primarily Influenced by pH

Traditionally, conservation and management of mountain pastures has been managed solely on the basis of visible biota. However, microorganisms play a vital role for the functioning of the soil ecosystem and, hence, pasture sustainability. Here, we studied the links between soil microbial (belowground) community structure (using amplicon sequencing of prokaryotes and fungi), other soil physicochemical and biological properties and, finally, a variety of pasture management practices. To this aim, during two consecutive years, we studied 104 environmental sites characterized by contrasting elevation, habitats, bedrock, and pasture management; located in or near Gorbeia Natural Park (Basque Country/Spain). Soil pH was found to be one of the most important factors in structuring soil microbial diversity. Interestingly, we observed a striking correlation between prokaryotic, fungal and macrofauna diversity, likely caused by interactions between these life forms. Further studies are needed to better understand such interactions and target the influence of different management practices on the soil microbial community, in face of the significant heterogeneity present. However, clearing of bushes altered microbial community structure, and in sites with calcareous bedrock also the use of herbicide vs. mechanical clearing of ferns.

A distinct section of the early bronze age society? Stable isotope investigations of burials in settlement pits and multiple inhumations of the Únětice culture in central germany

Inhumations in so-called settlement pits and multiple interments are subordinate burial practices of the Early Bronze Age Únětice culture in central Germany (2200-1700/1650 BC). The majority of the Únětice population was entombed as single inhumations in rectangular grave pits with a normative position of the body. The goal of the study was to test archaeological hypotheses that the deviant burials may represent socially distinct or nonlocal individuals. The study comprised up to two teeth and one bone each of 74 human individuals from eight sites and faunal comparative samples. The inhumations included regular, deviant burials in so-called settlement or storage pits, and multiple burials. We investigated radiogenic strontium isotope compositions of tooth enamel ((87) Sr/(86) Sr) and light stable isotope ratios of carbon and nitrogen of bone collagen (δ(13) C, δ(15) N) aiming at the disclosure of residential changes and dietary patterns. Site-specific strontium isotope data ranges mirror different geological properties including calcareous bedrock, loess, and glacial till. Independent from burial types, they disclose low portions of nonlocal individuals of up to some 20% at the individual sites. The light stable isotope ratios of burials in settlement pits and rectangular graves overlap widely and indicate highly similar dietary habits. The analytical results let to conclude that inhumations in settlement pits and multiple burials were two of the manifold burial practices of the Early Bronze Age. The selection criteria of the individuals for the different forms of inhumation remained undisclosed.

Deciphering neotectonics from river profile analysis in the karst Jura Mountains (northern Alpine foreland)

The study of the neotectonic activity in the Jura Mountains (northwestern most belt of the European Alps) represents a challenge in the application of quantitative geomorphology to extract landscape metrics and discuss potential coupling between tectonic, climatic and lithospheric mechanisms during the evolution of this mountain belt. The Jura Mountains are characterized by a karst calcareous bedrock, slightly affected by Quaternary glaciations, and by moderated uplift rates (<1 mm/year). In this study, we performed river profile analyses to decipher comparable geomorphological signals along tectonic structures within the entire Jura arc. Our results suggest higher tectonic activity in the High Range of the belt (internal part) than in the External Range, which is discussed in terms of deformation mechanisms. Integration of our results with previous geomorphological, neotectonic and geodetic studies from the literature leads us to propose new potential lithospheric and tectonic mechanism(s) driving the Plio-Quaternary deformation of the Jura Mountains. Our study finally reveals a regional-scale correlation between neotectonic deformations recorded by the Jura drainage network and the predicted isostatic rebound in response to Alpine Quaternary erosion. However, the correlation between our geomorphic signals and compressive structures suggests that the Jura Mountains could be still in horizontal shortening in both the High Range and the External Range.

Substrate influences ecophysiological performance of tree seedlings.

Unfavourable soil conditions frequently limit tree regeneration in mountain forests on calcareous bedrock. Rocky, shallow organic soils on dolomite pose a particular problem for tree regeneration due to commonly restricted water and nutrient supplies. Moreover, an often dense layer of understorey vegetation competes for the limited resources available. Hence, an array of interacting factors impairs tree seedlings' performance on dolomite, but there is little information on the ecophysiological mechanisms. We studied the effects of substrate, competing vegetation and foliar nutrient concentrations on the photosynthetic rate (A), stomatal conductance (gs) and leaf water potentials (ψ) of sycamore (Acer pseudoplatanus L.), beech (Fagus sylvatica L.), spruce [Picea abies (L.) Karst.] and larch (Larix decidua Mill.) under controlled (well-watered/drought-stressed) conditions and under prevailing field conditions. While A and gs of well-watered spruce in the pot experiment were reduced by the mineral substrate, the organic dolomite substrate with dense competing vegetation reduced gs and ψ of sycamore, spruce and larch under drought-stressed conditions in the field. For sycamore and spruce, A and gs were strongly correlated with foliar nitrogen (N) and potassium (K) concentrations in the pot experiment. In contrast, soil water primarily affected beech and larch. Finally, dense competing vegetation negatively affected A and gs of spruce and A of larch on dolomite. Our results highlight the critical role of N, K and water availability for tree seedlings in shallow soils on calcareous bedrock. On these sites, natural tree regeneration is at particular risk from episodic drought, a likely consequence of climate change.

Molecular and Morphological Snapshot Characterisation of the Protist Communities in Contrasting Alpine Glacier Forefields

Phagotrophic protist diversity in oligotrophic soils such as alpine glacier forefields is still poorly studied. Combining morphologic observations with molecular-based analyses, we assessed the diversity of major phagotrophic protist groups in two contrasting glacier forefields in the Swiss Alps (Tiefen glacier forefield, siliceous bedrock, and Wildstrubel glacier forefield, calcareous bedrock), at sites differing in soil development. Ciliates and heterotrophic flagellates could be detected with both approaches, while amoebae could be observed only microscopically. Soils from Tiefen and Wildstrubel glacier forefields harboured distinctly different ciliate, flagellate and amoebae communities. The ciliate clone libraries from the Tiefen glacier forefield were dominated by Oligohymenophorea-related sequences while those from the Wildstrubel glacier forefield were dominated by Spirotrichea-related sequences. Testate amoebae morphospecies of the genera Corythion , Cryptodifflugia , Euglypha and Tracheleuglypha were restricted to the Tiefen glacier forefield, while Centropyxis and Trinema to the Wildstrubel one. No ciliate sequences and only a few ciliate and testate amoebae morphospecies could be retrieved from unvegetated soils of both glacier forefields. The ciliate and testate amoebae community detected at unvegetated sites were a subset of the community developed at vegetated sites. Overall, our results suggest that alpine glacier forefields are colonised by a diverse community of phagotrophic protists which seems to be shaped by bedrock geology and vegetation cover.

Time-lapse surface waves to detect the stiffness of a grouted pile wall

We adopt the surface waves method to assess the stiffness of a grouted pile wall in the ground. The acquisition is performed in time-lapse mode, col¬lecting data soon after the grouting and a few months later and comparing the results. We use a 48-geophone single array, shooting in different positions along the array, in order to extract several dispersion curves to compare, provid¬ing a set of curves referring to different subsurface portions. We applied a spatial windowing based on a set of Gaussian windows with different shapes, optimising lateral and wave¬number resolutions. The comparison between the time-lapse dispersion curves shows an increase of the phase-velocity on the portion of the ground interested by the grouted pile wall. Surface waves data was collected also on a transect close to the grouted wall but not influenced by it, to obtain a reference line. The results demonstrate the reliability of time-lapse sur¬face wave data analysis to assess the changing of the mechani¬cal properties of the ground after consolidating works. The reliability and performance of surface waves have been tested to assess the stiffness of a grouted pile wall. The grouting injection in a urban area interested a depth ranging from 2 m up to 15 m, in a geological environment of a calcareous bedrock 15 m deep, with alluvium overburden. The project is based on the collaboration between Ramboll Denmark and Gamut srl, which is part of the Politecnico di Torino. Seismic data have been collected at two different periods to evaluate the changes of the stiffness of the consolidating ground; the approach is cost-effective because it is non-invasive and is capable of operating in urban areas. As the ambient noise limits the use of methods based on the travel¬time analysis (detection and picking of first time arrivals), surface waves, more energetic than P or S-waves, ensure a high data quality. The challenge is to obtain different surface waves of data along a wall, using a single seismic array.

Assessment and mobility of heavy metals in carbonated soils contaminated by old mine tailings in North Tunisia

The activity of the former Pb–Zn mine of Jebel Ghozlane, located in the extreme north of Tunisia, generated during the last century large quantities of tailings (extraction, flotation, gravimetry), which are deposited without concern for environmental issues. The tailings contain both primary (galena, sphalerite, pyrite) and secondary (cerussite, smithsonite, iron oxi-hydroxides) heavy metals bearing minerals. The gangue minerals are composed of calcite, dolomite, barite, celestite and quartz. The concentrations of Pb, Zn and Cd in the tailings vary from 1.2% to 5.7%, 9.3% to 13.6%, and 185.6 to 410.6mgkg−1, respectively. The soils surrounding the tailings piles, developed on a calcareous bedrock, are characterized by alkaline pH (H2O) ranging from 6.8 to 7.9. In addition, cation-exchange capacity (CEC) was low with a mean value of 4.25cmolkg−1 and organic matter (OM) content varied between 2.23% and 6.13%. These soils contain high amounts of Pb, Zn and Cd, that can reach 3052mgkg−1, 22,086mgkg−1 and 99.3mgkg−1, respectively. The contamination levels by heavy metals (HM) in the soils were evaluated using the modified degree of contamination (mCd). This evaluation shows that 60% of the analyzed soils are between the high degree and the ultra-high degree of contamination classes. The extraction tests using deionised water, salt (CaCl2), low-molecular-weight organic acids (LMWOAs) and chelating agent (DTPA) solutions were performed to evaluate the mobility of Pb, Zn and Cd in soil samples. Results show that, the extractability of heavy metals is slightly influenced by pH, CEC and total carbonate (TC) content of the soil. The amounts extracted with water and CaCl2 are negligible. The highest percentages of total heavy metals are extracted with DTPA (0.7–19.5% for Pb, 0.3–6.2% for Zn and 0.4–11.9% for Cd) and at a lesser degree by LMWOAs (0.1–0.8% for Pb, 0.1–2.5% for Zn and 0.1–1.9% for Cd). These results showed that the mobility of metals is generally very low and influenced by the high carbonate content of soils.

Cortinarius prodigiosus—a new species of the subgenus Phlegmacium from Central Europe

A new species, Cortinarius prodigiosus, is reported from the Czech Republic and Hungary. This medium-sized Phlegmacium is distinguished by a yellow pileus and lower part of stipe, by greyish-violet lamellae, and by strikingly bicolorous flesh: yellow in most parts of stipe and whitish in pileus. On the basis of its morphological and molecular characters (ITS rDNA and LSU D1/D2 domain), this novel taxon can be assigned to the Splendentes group of the section Calochroi; it occurs in thermophilous oak forests on calcareous bedrock.

Soil–methane sink increases with soil age in forefields of Alpine glaciers

In upland soils aerobic methane-oxidizing bacteria (MOB) catalyze methane (CH4) oxidation, and thus regulate the sole terrestrial sink for atmospheric CH4. While confirmed in mature upland soils, little is known about this important function in young mountainous soils in glacier forefields, which are progressively formed as a result of glacier recession. We assessed four attributes of the soil CH4 sink, i.e., soil-atmosphere CH4 flux (Jatm), CH4 oxidation activity (k), MOB abundance and variation in community composition along the 6–120-yr soil chronosequence in two Alpine glacier forefields on siliceous and calcareous bedrock. At most sampling locations soil CH4 profiles showed stable uptake of atmospheric CH4, with Jatm in the range of −0.082 to −2.2 mg CH4m−2 d−1. Multiple-linear-regression analyses indicated that Jatm significantly increased with soil age, whereas k did not. Instead, water content and CH4 profiles in the youngest soils often indicated dry, inactive top layers with k < 0.1h−1, and active deeper layers (0.2 h−1 ≤ k ≤ 11h−1) with more favorable water content. With increasing soil age the zone of highest CH4 oxidation activity gradually moved upwards and eventually focused in the 10–40-cm layer (0.2 h−1 ≤ k ≤ 16h−1). Copy numbers of pmoA genes significantly increased with soil age at both sites, ranging from 2.4 × 103 to 5.5 × 105 copies (g soil w.w.)−1, but also correlated with mineral nitrogen content. Terminal restriction-fragment-length-polymorphism and cluster analyses showed differences in MOB community composition apparently related to bedrock type rather than soil age. Yet, regardless of bedrock type, the soil CH4 sink established within a few years of soil development, and Jatm increased to values comparable to mature soils within decades. Thus, young mountainous soils have the potential to consume substantial amounts of atmospheric CH4, and should be incorporated into future estimates of global soil CH4 uptake.

Natural and anthropogenic controls over suspended sediments within a mountainous Appalachian watershed: implications for watershed restoration

The upper Elk River (620 km2), located in mountainous east-central West Virginia, is one of the premier cold-water fisheries in the eastern United States. However, sediment run-off from both forestry and non-forestry-related disturbance has the potential to threaten the quality of wild trout populations. General linear models were used to link spatial and temporal variation in total suspended solid (TSS) concentrations throughout the watershed to natural (i.e. landform and geology) and anthropogenic (forest management practices, other land-use disturbance [residential and commercial development, agriculture, and recreation], census roads) landscape attributes. In addition, through a unique paired sampling design, we tested the hypothesis that increasing levels of disturbance (i.e. forest management and other land use activities) within a watershed would result in a proportional increase in TSS concentrations. Spatial variation in TSS concentration was found to primarily be explained by land-use disturbance (partial R2 = 0.66) and secondarily by forest management practices (R2 = 0.13) and road area (R2 = 0.08). Results of a paired sampling design further indicated that significant increases in TSS concentrations were the result of intense land-use disturbance associated with activities other than forest management. Temporal variability (i.e. CV) in TSS was primarily related to dry flat area (partial R2 = 0.28) and percent calcareous bedrock (R2 = 0.21), suggesting natural sedimentation processes associated with karst geologies may exacerbate effects of anthropogenic disturbance. These results suggest that forestry-related best management practices being used in this mountainous region were effective in reducing sediment loads to nearby waterbodies, and improved management of non-forestry disturbance may be needed to protect this valuable fishery from sediment-related impacts.

Drainage system adjustment in response to the opening of the Rieti intermontane basin (Central Italy): geostatistical reconstruction of the PaleoFarfa River alluvial plain

The Rieti intermontane basin is one of the western tectonic depressions of the Central Apennines. Its infilling deposits are currently cut by the Farfa River, a left tributary of the Tiber River with a 132 km2 wide drainage basin. It currently flows from the Sabini Mts. (Central Apennines) into the Tiber River to the WSW. In the upper basin, the river cuts fluvial conglomerates and sands, which are Gelasian in age. Downstream, on the left side of the Tiber Valley, the facies show deltaic to clearly marine characteristics that indicate the presence of the Gelasian paleo-shoreline, which is also indicated by the finding of Lithodomus holes in the calcareous bedrock at an elevation of 260–277 m a.s.l. The shape of the Gelasian alluvial plain and delta has been outlined and redrawn via GIS techniques. We herein underline that during the Gelasian, the shoreline was located at the foot of the Fara in Sabina Mts. and that the alluvial plain of the PaleoFarfa River was much wider (approximately 700 km2) than the present, extending to the foot of the Reatini Mts. The reconstruction of both the basal and top surfaces of the old alluvial body provides evidence that the activity of Quaternary faults, responsible for the formation of the Rieti intermontane basin, strongly influenced the deposition of the alluvial body and finally caused the adjustment of the PaleoFarfa drainage system. Finally, from the shoreline elevation, a Pleistocene averaged uplift rate of 0.12/0.14 mm/year has been calculated for this sector of the Apennines.

Estimating Climate Resilience for Conservation across Geophysical Settings

Conservationists need methods to conserve biological diversity while allowing species and communities to rearrange in response to a changing climate. We developed and tested such a method for northeastern North America that we based on physical features associated with ecological diversity and site resilience to climate change. We comprehensively mapped 30 distinct geophysical settings based on geology and elevation. Within each geophysical setting, we identified sites that were both connected by natural cover and that had relatively more microclimates indicated by diverse topography and elevation gradients. We did this by scoring every 405 ha hexagon in the region for these two characteristics and selecting those that scored >SD 0.5 above the mean combined score for each setting. We hypothesized that these high-scoring sites had the greatest resilience to climate change, and we compared them with sites selected by The Nature Conservancy for their high-quality rare species populations and natural community occurrences. High-scoring sites captured significantly more of the biodiversity sites than expected by chance (p < 0.0001): 75% of the 414 target species, 49% of the 4592 target species locations, and 53% of the 2170 target community locations. Calcareous bedrock, coarse sand, and fine silt settings scored markedly lower for estimated resilience and had low levels of permanent land protection (average 7%). Because our method identifies—for every geophysical setting—sites that are the most likely to retain species and functions longer under a changing climate, it reveals natural strongholds for future conservation that would also capture substantial existing biodiversity and correct the bias in current secured lands.Identificación de Sitios Duraderos para la Conservación Usando la Diversidad del Paisaje y las Conexiones Locales para Estimar la Capacidad de Recuperación al Cambio ClimáticoResumenLos conservacionistas necesitan un método mediante el cual poder conservar la diversidad biológica mientras permiten que las especies y las comunidades se reorganicen con respecto al clima cambiante. Desarrollamos y probamos tal método, el cual basamos en características físicas asociadas con la diversidad ecológica y la capacidad de recuperación del sitio con respecto al cambio climático, en el noreste de Norteamérica. Mapeamos comprensivamente 30 escenarios geofísicos distintos basados en la geología y la elevación. Dentro de cada escenario geofísico identificamos sitios que estaban conectados por una cubierta natural y que tenían relativamente más microclimas indicados por la topografía diversa y los gradientes de elevación. Hicimos esto al puntuar cada hexágono de 450 ha en la región con estas dos características y al seleccionar aquellos que tuvieron una puntuación >SD 0.5 por encima del puntaje combinado promedio para cada escenario. Nuestra hipótesis fue que estos sitios con altas puntuaciones tuvieron la mayor capacidad de recuperación. Los comparamos con los sitios seleccionados por The Nature Conservancy por sus poblaciones de alta calidad de especies raras y sus ocurrencias de comunidades naturales. Los sitios con altos puntajes capturaron significativamente más de los sitios de biodiversidad de lo que se esperaba por casualidad (p < 0.0001): 75% de las 414 especies objetivo, 49% de las 4592 localidades de especies objetivo y 53% de las 2710 localidades de comunidades objetivo. Los escenarios de lecho rocoso calcáreo, arena gruesa y limo fino tuvieron puntos marcadamente más bajos para la capacidad de recuperación estimada y tuvieron niveles bajos de protección permanente de suelo (en promedio 7%). Ya que nuestro método identifica – para cada escenario geofísico – sitios que tienen mayor probabilidad de retener especies y funciones más tiempo bajo un clima cambiante, revela baluartes naturales para la conservación futura que también capturaría biodiversidad existente sustancial y corregiría el sesgo en tierras que actualmente están aseguradas.

Organic carbon stocks in forest soils of the German Alps

Forest soils are an important component of the global C cycle as they store large amounts of organic carbon (OC). Particularly in mountain forest ecosystems, soil organic matter is of crucial importance for site productivity and ecosystem services, but probably sensitive to climate change. Robust information about the OC stocks of mountain soils is rare due to their limited accessibility and large spatial heterogeneity. Our study covered the entire German Alps in a large-scale sampling campaign in 2011 and 2012, and provides soil organic carbon (SOC) stock data obtained from 150 forest soil profiles with different site conditions (elevation, aspect, air temperature, precipitation, parent material, soil type) and different intensities of historical forest utilization. The mean SOC stock of the investigated soils is 10.9kgm−2. The median value is 9.6kgm−2, indicating a skewed distribution of SOC stocks in forest soils of the German Alps. On average, 30% of the SOC stock is bound in the organic surface (O) layer, and 70% in the mineral soil. SOC stocks show a considerable dependency on site conditions (elevation, air temperature, precipitation, parent material). Soils in the German Limestone Alps show a significant OC stock gradient from W (Werdenfels) to E (Berchtesgaden region), which probably has been caused by more intense historical forest utilization in the latter compared to the former region. Soils at high-elevation sites with low air temperature and high precipitation have particularly large OC stocks. However, the elevation and climate effect is statistically significant only for precipitation due to the large variation of other factors with relevance for SOC stocks (e.g. parent material, soil type) in a given elevation/climate stratum. Histosols on consolidated calcareous bedrock and Histic Rendzic Leptosols have significantly larger SOC stocks than Rendzic Leptosols, Rendzic Cambisols, or soils on easily-weatherable parent material (marl, clayey sandstone, moraine). The fact that SOC stocks in forest soils of the German Alps are by trend larger at high-elevation sites with low air temperature and high precipitation suggests a sensitivity to the ongoing climate change and a risk of SOC losses for the predicted climate scenarios.

FOREST AND SCRUB COMMUNITIES WITH GREEN ALDER (ALNUS VIRIDIS) IN SLOVENIA

Abstract This paper provides phytosociological tables that describe scrub and forest communities with Alnus viridis in the Slovenian Alps. We described three new associations: Rhododendro hirsuti-Alnetum viridis (a green alder community on calcareous bedrock in the Eastern and Southeastern Alps), Huperzio selagi-Alnetum viridis (a green alder community in the silicate rocks under Mt. Komen in the eastern Savinja Alps) and Alno viridis- Sorbetum aucupariae (a successional stage of mountain ash and green alder on potential beech sites in the foothills of the southern Julian Alps; similar stages are known also elsewhere in the Alps), and presented additional three associations (Polysticho lonchitis-Fagetum, Rhodothamno-Laricetum and Rhododendro hirsuti-Pinetum mugo) whose stands comprise green alder.

Detection and imaging of piping sinkholes by integrated geophysical methods

ABSTRACTPiping sinkholes may naturally develop in the case of a thick overburden overlying calcareous bedrock. Their detection and imaging is a challenging task for geophysical methods, not only because of the required resolution and depth of penetration, but also because major pitfalls may arise, in such geologically complex areas, from the speculative interpretation of geophysical anomalies as geological features. Data integration from different geophysical methods is essential to remove these interpretation ambiguities, caused by large near‐surface gradients and heterogeneities in the soil properties, as well as by oscillations of the water table and anomalous water circulation.We present an investigation procedure consisting of the sequential application and integrated interpretation of Electrical Resistivity Tomography (ERT), Seismic Refraction Tomography (SRT) and Self Potential (SP) measurements for locating and monitoring piping sinkholes with application to a site in Central Italy. This approach is a compromise between resolution and cost‐effectiveness, and it is designed to be economically affordable by the private end user.In complex geological scenarios, it is usually not possible to rate a single geophysical technique as superior to all the others in terms of resolution, cost‐effectiveness and diagnostic capability. The independent information coming from the different geophysical methods is the key to removing interpretation ambiguity when evaluating the position and the development over time of the piping sinkholes. The application of the proposed investigation procedure allowed us to individuate a small area subject to the formation of a piping sinkhole. The geophysical results were confirmed about one year after the execution of the geophysical measurements, as the site exhibited surface evidence of a piping sinkhole, with the formation of a small pond filled with sulphurous water and gases coming from below.