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Glacial extent and mass balance are sensitive climate proxies providing solid information on past climatic conditions. However, series of annual mass-balance measurements of more than 60 years are scarce. To our knowledge, this is the first time the latewood density data (MXD) of the Swiss stone pine (Pinus cembra L.) have been used to reconstruct the summer mass balance (Bs) of an Alpine glacier. The MXD-based Bs well correlates with a Bs reconstruction based on the May to September temperature. Winter precipitation has been used as an independent proxy to infer the winter mass balance and to obtain an annual mass-balance (Bn) estimate dating back to the glaciological year 1811/12. The reconstructed MXD/precipitation-based Bn well correlates with the data both of the Careser and of other Alpine glaciers measured by the glaciological method. A number of critical issues should be considered in both proxies, including non-linear response of glacial mass balance to temperature, bedrock topography, ice thinning and fragmentation, MXD acquisition and standardization methods, and finally the ‘divergence problem’ responsible for the recently reduced sensitivity of the dendrochronological data. Nevertheless, our results highlight the possibility of performing MXD-based dendroglaciological reconstructions using this stable and reliable proxy.

Based on the tree-ring chronology, we studied the radial increment of Swiss stone pine (Pinus cembra L.) and common spruce, or Norway spruce (Picea abies L.) as indicators of dendrochronological studies and, based on tree-ring chronology, reconstructed the annual changes of stem biomass and the amount of carbon accumulated in it by P. cembra and P. abies in the Gorgany Nature Reserve. Swiss stone pine stands are of great zoological importance as biotopes of nutcracker (Nucifraga caryocatactes L.), crossbill (Loxia curvirostra L.), capercaillie (Tetrao urogallus L.) and other representatives of rare boreal fauna. Samples were taken from trees of the Playa forest district of the Brusturyan Forest Hunting Range State Enterprise of the Transcarpathian Regional Forestry Administration (P. cembra and P. abies) from trees that did not have visual signs of damage in the Gorgany Nature Reserve. By cross-dating the radial increments of two radii for each tree, individual chronological series were drawn up. Carbon sequestration in P. cembra and P. abies stem wood was evaluated on the basis of dendrochronological analysis of radial increment. The accuracy of cross-dating of dendrochronological series of individual trees, individual chronological series, and representativeness of the generalized series were verified by conventional methods. It was found that the average annual radial increment of the trees under study is 11.48 mm in P. cembra and 14.39 in P. abies, and varies in the range of 1.86–5.49 mm. The data obtained indicate an increase in the ability of P. cembra and P. abies to accumulate carbon with increasing age. The study of carbon sequestration in the stem wood of P. cembra and P. abies, based on dendrochronological analysis, made it possible to reconstruct the annual variation in stem biomass increment and accumulated carbon. The analysis of interdependence of the radial increment of P. cembra and P. abies in the Gorgany Nature Reserve and the value of carbon-containing greenhouse gases in the atmosphere, carried out by the augmented data sample, made it possible to specify the periods most significant for the formation of annual rings. The reaction in radial increment is most pronounced from June to September, with the annual values of carbon-containing greenhouse gases being maximally reflected in radial increment for the period from October to April.

We analyze annually resolved tree-ring stable carbon (I´13C) and oxygen (I´18O) isotopic chronologies from Swiss stone pine (Pinus cembra L.) in Romania. The chronologies cover the period between 1876 and 2012 and integrate data from four individual trees from the Calimani Mts in the eastern Carpathians where climatic records are scarce and starts only from 1961. Calibration trials show that the I´13C values correlate with local April-May relative humidity and with regional to larger scale (European) summer precipitation. I´18O correlates significantly with local relative humidity, cloud cover, maximum temperature, as well as European scale drought conditions. In all cases, the climate effects on I´13C values are weaker than those recorded in the I´18O data, with the latter revealing a tendency towards higher (lower) values of I´18O during extremely dry (wet) years. The most striking signal, however, is the strong link between the interannual I´18O variability recorded in the Calimani Mts and large-scale circulation patterns associated with North Atlantic and Mediteraneean Sea sea surface temperatures. High (low) values of I´18O occur in association with a high (low) pressure system over the central and eastern part of Europe and with a significantly warmer (colder) Mediterranean Sea surface temperature. These results demonstrate the possibility of using tree ring oxygen isotopes from the eastern Carpathians to reconstruct regional drought conditions in eastern Europe on long-term time scales and larger scale circulation dynamics over the pre-instrumental periods.

Key message The lack of elevational changes in electrical resistivity in Pinus cembra trunks indicated consistent growth and hydraulics across elevations. Though, electrical resistivity tomograms exhibited pronounced temperature-driven seasonal changes. Abstract Alpine conifers growing at high elevation are exposed to low temperatures, which may limit xylogenesis and cause pronounced seasonal changes in tree hydraulics. Electrical resistivity (ER) tomography enables minimal invasive monitoring of stems in situ. We used this technique to analyze Pinus cembra trunks along a 400 m elevational gradient up to the timberline and over seasons. Furthermore, ER data of earlywood across tree rings were compared with the respective specific hydraulic conductivity (KS), measured on extracted wood cores. ER tomograms revealed pronounced changes over the year and a strong correlation between average ER (ERmean) and air and xylem temperatures. Surprisingly, no elevational changes in ERmean, earlywood ER or KS were observed. ER data corresponded to variation in earlywood KS, which decreased from the youngest (ca. 4–5 cm2s−1 MPa−1) to the oldest tree rings (0.63 ± 0.22 cm2s−1 MPa−1). The lack of changes in ER data and earlywood KS along the study transect indicated consistent growth patterns and no major changes in structural and functional hydraulic traits across elevation. The constant decrease in earlywood KS with tree ring age throughout all elevations highlights the hydraulic relevance of the outermost tree rings in P. cembra. Seasonal measurements demonstrated pronounced temperature effects on ER, and we thus recommend a detailed monitoring of trunk temperatures for ER tomography.

The term 'Little Ice Age' (LIA) is classically used to define a period of repeated and extensive glacier advances during the last millennium. In the meanwhile, this term is also used to address the period of relatively low temperatures between the Medieval Climate Anomaly (MCA), or Medieval Warm Period, and present-day warming. The end of the LIA is generally set to the mid or late 1800s CE, however, the published onset dates of the LIA are more variable from the mid 1200s to the late 1500s. At Mont Mine and Morteratsch glaciers, Swiss Alps, we sampled and subsequently analysed detrital as well as in situ tree remnants from the early LIA period. At both glaciers, trees with lifespans of up to about 400 years were buried at various lateral moraine sites. The corresponding advance of both glaciers can be traced from the 1280s until the 1310s. At Morteratsch glacier, this early LIA advance phase culminated likely around 1375 CE. Evidence collected at both glaciers indicates that the ice surfaces were at least c. 12-15 m from the lateral moraine crests deposited during the maximum extent of the LIA. This suggests a similar (though very slightly weaker) magnitude than later LIA advances at our sites. The advances of Mont Mine and Morteratsch glaciers coincide with relatively cool summer temperatures from the late 1200s to the late 1300s. Taken together, the onset of the Little Ice Age in the Alps can be considered to be c. 1260 CE. The Little Ice Age was not a uniform period, but had several phases as can be derived from the records of Alpine glaciers and summer temperatures. We propose a subdivision of the LIA in the European Alps into an early (1260-1380 CE), an intermediate (1380-1575 CE) and a main (1575-1860 CE) phase., The Holocene, 32 (7), ISSN:0959-6836, ISSN:1477-0911

International audience; Under climate change, modifications on plants’ growth are expected to be the strongest at species margins. Therein, tree acclimation could play a key role as migration is predicted to be too slow to track shifts of bioclimatic envelops. A requirement is, however, that intra-population genetic diversity be high enough for allowing such adaptation of tree populations to climate change. In this study, we tested for the existence of relationships between genetic diversity, site environmental conditions, and the response of annual tree growth to climate of Pinus cembra at its southern limit in the Alps. Site-specific climatic and environmental factors pre- dominantly determined the response of trees along the precipitation gradient. The growth-climate interactions were chiefly linked to mean annual precipitation and temperature, slope and tree-size, and less to genetic di- versity. We show that genetic background of Pinus cembra has exclusively indirect modulating power with limited effects on tree-ring formation, and within the southern limit in the Alps, genetic variability is not necessarily well expressed in the patterns of annual tree growth. Our results may imply little adaptive capacity of these pop- ulations to future changes in the water balance.

C/N/P stoichiometry offers important indicators of ecosystem function and productivity. The aim of this research was to determine how planting methods in biogroups influence C/N/P stoichiometry in soil and plants. We hypothesised that planting methods, consisting in different initial spacing and shape would affect the growth characteristics of trees, and consequently, change soil properties – microbiological activity, in particular. This research examined two species that have different ecological requirements, silver fir (Abies alba Mill.) and Swiss stone pine (Pinus cembra L.), grown in the upper mountain zone, 1200 m above sea level. We established 48 experimental plots with two planting methods and two species in 2011. The soil and plant samples for laboratory analysis were taken in September 2020. In the first planting method 49 seedlings at regular 1 × 1 m spacing in a square plot (PM1) were planted, while in the second method 50 seedlings in two rhombus plots with 50 × 50 cm spacing (PM2) were planted. We determined the basic physicochemical properties and enzymatic activity in soil samples, and we recorded the content of C, N and P in testing needle samples from the trees. We also calculated the C/N, C/P and N/P ratios for both the soil samples and the plants. We found that the formation of biogroups with smaller spacing during stand renewal influenced the selected soil properties; within the biogroups with smaller spacing, an increase in soil biochemical activity was found. Our research confirms that planting methods and species are essential contributors to the C/N/P stoichiometry of soils and plants. The C/N/P stoichiometry of the soil samples from the different species and the different planting methods ranged between 928/37/1 and 1087/42/1. In the case of the Swiss stone pine needles, we noted a narrower C/N/P stoichiometry compared to the fir needles, regardless of the planting method. C/N/P stoichiometry is a useful tool for reflecting the nutrient cycle in mountain ecosystems, and our research shows that in the case of species with higher ecological requirements, stoichiometry can indicate nutrient limitation. In higher mountainous locations, nitrogen and phosphorus deficiencies are the main limiting factor. In the case of fir trees, the method of planting helps to reduce nutrient limitation and improve growth characteristics.

Global commercial and recreational transport may lead to the unintentional invasion of insect species, which in turn may pose a threat to native organisms. In this study, we aimed to assess whether the economically important pest of Pinus sylvestris L., moth Dendrolimus pini L. (DP), is able to feed on nine other pine species, and how this will affect its survival, performance, growth, and development. We carried out food choice tests and a no-choice laboratory feeding experiment. We found that this insect mostly preferred its prime host, but also Pinus cembra L., Pinus contorta Douglas ex Loudon, Pinus nigra J.F.Arnold, and Pinus ponderosa Douglas ex C.Lawson. The performance test revealed a host-specific response of DP to the host plant. This response was manifested in a large variation in body mass as well as in a decrease or increase in life-history traits, such as fecundity, and wing morphology parameters. However, the larvae’s choice of particular hosts corresponded to the results of the performance test. Larvae more willingly selected food allowing better results in their performance. Larvae achieved better values of growth and development when fed on European and North American pine species or on species with two- and three-needle fascicles. In addition, attractants and repellents in needles of different pine species were chemically analyzed. Variations in the secondary metabolite composition as well as the specific leaf area of different pine species effectively explained the results found in the insects, but the content of sugars and nitrogen remains to be elucidated. We speculate that DP poses a serious threat to large areas of pine forests, if transferred, as it can survive and develop on many economically important tree species in North America and Europe.

Cardiorespiratory interactions (CRIs) reflect the mutual tuning of two important organismic oscillators—the heartbeat and respiration. These interactions can be used as a powerful tool to characterize the self-organizational and recreational quality of sleep. In this randomized, blinded and cross-over design study, we investigated CRIs in 15 subjects over a total of 253 nights who slept in beds made from different materials. One type of bed, used as control, was made of melamine faced chipboard with a wood-like appearance, while the other type was made of solid wood from stone pine (Pinus cembra). We observed a significant increase of vagal activity (measured by respiratory sinus arrhythmia), a decrease in the heart rate (as an indicator of energy consumption during sleep) and an improvement in CRIs, especially during the first hours of sleep in the stone pine beds as compared to the chipboard beds. Subjective assessments of study participants’ well-being in the morning and sub-scalar assessments of their intrapsychic stability were significantly better after they slept in the stone pine bed than after they slept in the chipboard bed. Our observations suggest that CRIs are sensitive to detectable differences in indoor settings that are relevant to human health. Our results are in agreement with those of other studies that have reported that exposure to volatile phytochemical ingredients of stone pine (α-pinene, limonene, bornyl acetate) lead to an improvement in vagal activity and studies that show a reduction in stress parameters upon contact with solid wood surfaces.

Cardiorespiratory interactions (CRIs) reflect the mutual tuning of two important organismic oscillators—the heartbeat and respiration. These interactions can be used as a powerful tool to characterize the self-organizational and recreational quality of sleep. In this randomized, blinded and cross-over design study, we investigated CRIs in 15 subjects over a total of 253 nights who slept in beds made from different materials. One type of bed, used as control, was made of melamine faced chipboard with a wood-like appearance, while the other type was made of solid wood from stone pine (Pinus cembra). We observed a significant increase of vagal activity (measured by respiratory sinus arrhythmia), a decrease in the heart rate (as an indicator of energy consumption during sleep) and an improvement in CRIs, especially during the first hours of sleep in the stone pine beds as compared to the chipboard beds. Subjective assessments of study participants’ well-being in the morning and sub-scalar assessments of their intrapsychic stability were significantly better after they slept in the stone pine bed than after they slept in the chipboard bed. Our observations suggest that CRIs are sensitive to detectable differences in indoor settings that are relevant to human health. Our results are in agreement with those of other studies that have reported that exposure to volatile phytochemical ingredients of stone pine (α-pinene, limonene, bornyl acetate) lead to an improvement in vagal activity and studies that show a reduction in stress parameters upon contact with solid wood surfaces.

Due to anthropogenic impact on vegetation cover, importance of the outphytosozological studies of coniferous plants of the Ukrainian Carpathians is emphasized. Pinus cembra is one of the rare species of trees in Europe and its in situ and ex situ conservation in Ukraine is required. At present, P. cembra is under protection in its natural habitats within 25 objects of the nature reserve fund of Ukraine and 71 objects of artificial plantations (in total of 10 categories). The network of the protected areas consists of two biosphere reserves, one nature reserve, six national nature parks, one regional landscape park, eight reserves (of which five are botanical), 13 botanical nature monuments, seven protected forest parcels, 14 botanical gardens, 16 dendrological parks, and 21 monuments of landscape art. The largest natural plant communities of P. cembra are located in Gorgany Nature Reserve (539 ha). As a result of the inventory studies, the boundaries of its cultivation area in Ukraine were defined. It is obvious that the most widespread cultivation of P. cembra is within the Carpathian Mountains (20 objects). The Forest-Steppe zone of Ukraine and the zone of deciduous forests of Ukraine (14 and 16 objects, respectively) provide sufficiently suitable ecological conditions for cultivation of P. cembra. The least number of artificial plantations under protection were found in the Mixed Forest zone (4) and the Steppe zone of Ukraine (6 objects). The largest number of the protected natural forests (16) and artificial plantations (11 objects) was registered in Ivano-Frankivsk Region. Plants aged ca. 250 years were revealed under artificial conditions (in cultivation).

Current distributions of Swiss stone pine mostly cover the mountain regions of Europe (Alps and Carpathians). Easternmost distribution of this species is located in western Ukraine. Due to environmental fragmentation in Eastern Carpathians and competition with Norway spruce and other species, marginal populations of Swiss stone pine create isolated island, where other species are not able to cope with harsh conditions. Still, Pinus cembra L. play an important role for soil-formation and soil-protection in high elevations. The evidence of recent reduction in the area of Swiss stone pine raises the question whether the introduction of this species at lower altitudes can be successful? According to the studies conducted on reciprocal transplant experiments, Swiss stone pine population from higher elevation are able to profit in low elevation sites. Thus, parallelly with gene conservation activity, the possibilities of assisted migration should be recognized for this species.

We present a comparative study on a 700-yr sequence of dendrochronologically ordered tree-rings of Pinus cembra originating from Eastern Carpathians for the period AD 1009–1709. This period covers the solar minima of the Little Ice Age. The aim of this study was to assess the accuracy of our radiocarbon (14C) determinations interpreted on the IntCal13 calibration data and to observe any apparent offsets. The 14C measurements on single and double tree-rings were “wiggle-matched” to secure the dendrochronology cross-matching of all the Pinus cembra wood pieces. The results showed a very good agreement between the age datasets for four out of five wood trunks. However, for one of them a new cross-matching was performed after a quality assurance test, establishing an earlier 48-yr position, recommended by wiggle-matching Bayesian statistics and dendrochronological analysis. Following this adjustment, the quantification of the 14C level variability with respect to the IntCal13 calibration curve was obtained by calculating Δ14C for all tree-ring samples. As a final conclusion, an insignificant 14C concentration offset of –0.63 ± 3.76‰ was found for the Romanian samples.

Pinus cembra, stone pine, is an Alpine coniferous tree rich in aromatic compounds. Twigs with needles are used commonly to produce essential oils for various purposes in pharmacy, food industry, and cosmetics. Hydrolates as byproducts of hydrodistillation encounter increasing interest owing to their aromatic properties. The variabilities in the compositions of essential oil and the related hydrolates are studied in samples from individual trees growing on three sites in the Austrian high mountain range. The essential oils have been obtained by steam distillation. All essential oils contained monoterpene hydrocarbons as main compounds, especially α-pinene (36–37%), β-phellandrene (27–30%), and β-pinene (7–9%). In contrast, the volatiles in the corresponding hydrolates were dominated by oxidized compounds as α-terpineol (28–34%), terpinen-4-ol (6–8%), and verbenone (6–7%). The pinene rich essential oils might be used in pharmacy as pinene containing oils from other Pinus species, while the hydrolates are of interest for cosmetics and other well-being promoting products.

After drought-induced embolism and repair, tree xylem may be weakened against future drought events (cavitation fatigue). As there are few data on cavitation fatigue in conifers available, we quantified vulnerability curves (VCs) after embolism/repair cycles on eight European conifer species. We induced 50% and 100% loss of conductivity (LC) with a cavitron, and analyzed VCs. Embolism repair was obtained by vacuum infiltration. All species demonstrated complete embolism repair and a lack of any cavitation fatigue after 50% LC . After 100% LC, European larch (Larix decidua), stone pine (Pinus cembra), Norway spruce (Picea abies), and silver fir (Abies alba) remained unaffected, while mountain pine (Pinus mugo), yew (Taxus baccata), and common juniper (Juniperus communis) exhibited 0.4–0.9 MPa higher vulnerability to embolism. A small cavitation fatigue observed in Scots pine (Pinus sylvestris) was probably biased by incomplete embolism repair, as indicated by a correlation of vulnerability shifts and conductivity restoration. Our data demonstrate that cavitation fatigue in conifers is species-specific and depends on the intensity of preceding LC. The lack of fatigue effects after moderate LC, and relevant effects in only three species after high LC, indicate that conifers are relatively resistant against cavitation fatigue. This is remarkable considering the complex and delicate conifer pit architecture and may be important considering climate change projections.

International audience; We used pollen, plant macrofossil, and charcoal records to investigate local long-term timberline shifts and changes in vegetation composition in relation to fire activity at the modern upper forest limit (ca. 2,000 m a.s.l.) in the Mont Bégo area, Maritime Alps of France and Italy. The area is an important place for Alpine archaeology because it has thousands rock-art carvings whose age cannot be directly assessed. Our new record confirms the occurrence of distinct land use phases (7,450–7,150, 6,200–4,900, and 4,250–3,700 cal bp), as suggested by earlier studies of rock art typology. Moreover, the vegetation reconstruction from macrofossils, with co-dominance of Pinus and Betula, suggests that early Holocene conditions were moister than in drier inner Alpine valleys, where Larix decidua played a more important role, both in the past as well as in modern timberline forests. After 8,000 cal bp, the timberline shifted upwards and mixed Abies alba and Pinus cembra stands established around the study site. These fire sensitive trees were finally replaced during the Bronze Age (around 4,000 cal bp) by L. decidua, which still dominates the subalpine woodlands in the area today. Our study supports the notion that while the range of A. alba has been reduced at the colder end of its natural distribution, that of L. decidua has been widened by land use changes and fire disturbances to create high alpine wood pastures.

Age-related trends are present in tree-ring widths (TRW), but their presence in tree rings isotope is debated. It is unclear how cambial age influences the relationships between TRW and isotopes. Tree-ring isotopes of alpine larch and cembran-pine trees showed only trends in the juvenile period (&gt, 100 years), which might mask the inter-relations between tree-ring proxies during cambial age. This work tries to unmask the age-trend influences by examining the correlations in TRW—stable isotopes with and without age-trend correction. The non-detrended and linear-detrended values of TRW, of δD and δ18O showed significant correlations for ages up to 100 years, but not afterward. However, the correlation values, after spline or first-difference time-series detrending, were not age-related. Thus, detrending methods affect the correlations in the juvenile phase and may affect climate-related interpretations. The correlations between TRW and δ13C were not age-related, while those among the isotopes were significant throughout the ages. The correlation between δ13C and δD was the exception, as it became significant only after age &gt, 100 years, suggesting a different use of reserves in the juvenile phase. In conclusion, the relationships among the tree-ring parameters are stable in all the different detrend scenarios after the juvenile phase, and they can be used together in multi-proxy paleoclimatic studies. The data of the juvenile phase can be used after spline-detrending or first-difference time-series calculation, depending on the purpose of the analysis to remove age-related trends. The work also provides clues on the possible causes of juvenile age trends.

Radial and height growth rates are suitable indicators of impending tree mortality risk of adult trees, but their applicability to saplings remains unknown. We compared radial growth of living and dead saplings of different heights and quantified the effects of light availability, growth and tree size on mortality. We sampled an equal number of living and dead saplings of four coniferous tree species (Pinus cembra, Larix decidua, Picea abies, Abies alba) in nine forests along an elevational gradient of the Swiss Alps. Based on tree-ring widths reconstructed from stem disks at multiple tree heights, we calculated radial growth rates. We observed a divergent pattern in radial growth of living and dead saplings, with reduced growth of dead saplings starting several years prior to death. By matching living and dead saplings of similar ages, we tested whether mortality probabilities of saplings were influenced by light availability, recent growth rates and diameter. Mortality of coniferous saplings in mountain forests was mainly influenced by light availability, with changing effects along the elevational gradient. Recent radial growth rate and tree size were only weakly associated with sapling mortality. Our study establishes the importance of long-term predisposing factors for the mortality probability of conifer saplings in mountain forests, thus extending well-established findings from the adult stage to saplings, which represent a critical stage of forest dynamics., Forest Ecology and Management, 479, ISSN:0378-1127, ISSN:1872-7042

A new species, Lestodiplosis pinei Gagne (Diptera: Cecidomyiidae), from the United States is described from males, females, pupae and larvae. Larvae are egg predators of Pineus strobi Hartig, Pineus pini Goeze and Pineus cembrae (Cholodkovsky) (Hemiptera: Adelgidae). This is the first North American record for P. cembrae, which was found feeding on Pinus cembra L. planted at Arnold Arboretum in Massachusetts. Lestodiplosis juniperina (Felt) is redescribed as similar to L. pinei and for having once been considered to include specimens now identified as L. pinei. Lestodiplosis cerasi Felt and Lestodiplosis novangliae Felt are new synonyms of L. juniperina.

Pinus cembra forests are limited to the Alps and Carpathians. Although several studies regarding their structure were carried out in some locations in the Tatra Mts. it required further investigations. Therefore, the aims of this study were to describe the stand and shrub structure of P. cembra forests, compare their structure with the Picea abies forests and analyse differences between silicate and calcicolous P. cembra forests in the Tatra Mts. The data were collected on the 16 sampling plots (500 m2), in the Swiss stone pine and Norway spruce forests. We measured the diameter at breast height (dbh) of each tree and recorded the young trees and shrubs. In order to compare species composition between silicate and calcicolous P. cembra forests, we made 91 releves in their entire range of distribution (917 ha). Furthermore, we examined the share of main tree species along the altitude and inclination gradients, using the GAM models. The tree density in the P. cembra forests reaches 618 stems per ha, whereas their basal area (BA) 23.17 m2 ha-1. Main tree species are P. cembra and P. abies. P. cembra dominates in the higher thickness classes. The BA and dbh structure varies significantly between P. cembra and P. abies forests. The most abundant juveniles are P. abies and Sorbus aucuparia. The differences between forests growing on different substrate are relatively low. The altitude has a significant impact on the share of P. cembra (increase) and P. abies (decrease). The inclination has a significant impact on the increase of share of P. cembra.

The present note intends to challenge, based on field observations, the definition of treeline and argues for considering the upper occurrences of tree-species as an integrative result of historical and contemporary processes acting on high-altitude socio-ecosystems. A field survey of Pinus cembra growing above 2800 m asl was conducted, in an ecoregion of southwestern Alps, straddling France and Italy (Queyras-Mt Viso area). Pines were described (height, density) and their habitats were contextualized (altitude, slope degree and exposure, bedrock). Individuals of Pinus cembra are commonly growing between 2800 and 3200 m asl, generally on east-facing, steep and rocky slopes, with a pine density decreasing with altitude. Pines are generally dwarf-shaped, sometimes erected or prostrated. Their needles are half the size compared to those of pines growing in subalpine forests. Pine morphology indicates harsh growing conditions, notably strong wind, aridity and frost. These habitats constitute visually emerging objects attractive for the nutcracker caching behaviour. This setting acts as a positive passive driver for pine at high altitudes, which is further favoured by intense atmospheric moisture supplied by the east from the Po valley. Steep and rocky slopes exclude livestock, likely explaining why these pines are located in grass-less habitats. These tree clusters constitute remarkable “sky-island” populations. Larix decidua and Pinus uncinata were also recorded at exceptional altitudes but P. cembra is the most frequent species in high alpine conditions. These observations altogether highlight a complex pattern of tree-species line in the western Alps, and probably beyond.

Over the past few decades, mean summer temperatures within the Carpathian Mountains have increased by as much as 2 °C leading to a projected increased forest fire risk. Currently, there are no paleofire records from the Western Carpathians that provide the long-term range of natural variability to contextualise the response of upper-montane forests to future environmental change and disturbance regimes. We present the first high-resolution Holocene fire history record from the upper-montane ecotone from the High Tatra Mountains, Slovakia, as well as provide a regional synthesis of pan-Carpathian drivers of biomass burning in upper-montane forests. Our results illustrate that forest composition and density both greatly influence biomass burning, creating two different climate-fuel feedbacks. First, warmer conditions in the early Holocene, coupled with generally higher abundances of Pinus sp., either P. cembra and/or P. mugo/sylvestris, created a positive climate-fuel relationship that resulted in higher amounts of biomass burning. Second, cooler and wetter late Holocene conditions led to denser Picea abies upper-montane forests, creating a negative climate-fuel feedback that reduced biomass burning in upper-montane forests across the Carpathians. Given that warmer and drier conditions are expected across the entire Carpathian region in the future, our results illustrate how future climate change could potentially create a positive climate-fuel relationship within upper-montane forests dominated by Picea abies and Pinus cembra and/or P. mugo/sylvestris.

Four of the waterways that flow into the Danube have their source in Italian localities: in Lombardia Region (Valtellina, in the Valle di Livigno), Trentino-Alto Adige Region (Val Pusteria and Val Venosta), and the Friuli-Venezia Giulia Region (Tarvisiano, in the Val Canale). In all, it is estimated that almost 565 km2 of Italy lies within the hydrographic (catchment) basin of the Danube, corresponding to 0.15% of the total Danube basin. Livigno and Venosta are the most continental valleys, as demonstrated by the strong presence of Pinus cembra and Larix decidua. The upper Drava valley is still of the continental type, but manifesting a lower degree of continentality, due to moist air currents from the lower part of the Valley, as seen by the presence of Abies alba and Picea abies. Finally, the Val Canale, with oceanic characteristics as demonstrated by the widespread presence of Fagus sylvatica and Abies alba.

V delu smo raziskali edini znani domnevno avtohtoni nahajališči cemprina (Pinus cembra L.) v Sloveniji: pod Krnesom in pri Beli peči, obe v pogorju Smrekovca. Želeli smo opisati stanje in preveriti, ali je cemprin v Sloveniji samonikel. Z GPS napravo smo določili pozicije osebkov cemprina, osebke premerili, določili razdaljo do najbližjega sosednjega cemprina, ocenili zdravstveno stanje, določili starost dveh osebkov z metodo izvrtkov in zabeležili znake pomlajevanja. Nahajališča in pozicije posameznih cemprinov v pogorju Smrekovca prikazujemo na izsekih kart glede na relief, geološko podlago, vrsto tal, gozdne združbe in rabo tal. Pod Krnesom uspeva 11 cemprinov, pri Beli peči 4. Cemprini pri Beli peči so v povprečju višji in debelejši, verjetno tudi starejši. Starost dveh vzorčenih cemprinov pod Krnesom na višini debla 1,3 m je 62 oz. 66 let. Povprečni debelinski prirastek pri vzorčenem cemprinu na gozdnem robu je 1,97 mm/leto, v sestoju pa 1,25 mm/leto. Pod Krnesom smo našli osebek mladja in na dveh osebkih opazili storže. Za rastišči, opisani kot smrekovje z gozdno bekico (Luzulo sylvaticae-Piceetum), je značilna gosta podrast, ki bi jo bilo treba na manjših ploskvah odstraniti in raziskati pogostnost pojavljanja pomladka cemprina. Lahko gre za marginalno populacijo cemprina na njegovem robnem rastišču na skrajnem vzhodnem območju Alp. Najpomembnejši argument proti samoniklosti je razporeditev 9 osebkov pod Krnesom ob deželni meji in frati. Zapisov o saditvi ni. Cemprini v pogorju Smrekovca naj tudi v prihodnje obdržijo status dendrološke naravne vrednote. In the thesis the only two sites where the Swiss pine (Pinus cembra L.) is considered to occur natively in Slovenia were studied: one below the Krnes mountain and one near the Bela Peč mountain, both part of the Smrekovec massif. Our intention was to document the situation and to ascertain whether the Swiss pine is indigenous in Slovenia. The exact locations of the individual trees were determined using a GPS device, the trees were measured in terms of size and inspected in terms of health, the distances between closest neighbouring trees were calculated, and two individuals' ages determined by increment boring. Also noted were signs of rejuvenation. The two sites and the individual Swiss pines' locations in the Smrekovec massif are indicated on sections of relief, bedrock, soil, forest phytocoenoses and land use maps. Eleven Swiss pines were found to grow below the Krnes mountain and four near the Bela Peč mountain. The latter have greater mean diameters and heights and are probably older than the former. The two trees from below the Krnes that were bored at the height of 1.3 m are aged 62 and 66. The individual growing on the edge of the forest has a mean annual increment of 1.97 mm while the other, growing inside the forest, has 1.25 mm. A Swiss pine seedling was found below the Krnes, and cones were seen on two individuals. The two sites, described as woodrush-spruce woods (Luzulo sylvaticae-Piceetum), are characterised by dense undergrowth which would have to be removed in a few patches in order to study the presence of Swiss pine seedlings. Potentially, the two sites are home to marginal populations of Swiss pine at the edge of its natural range in the easternmost part of the Alps. The most prominent argument against nativity is the distribution of the nine individuals below the Krnes % it follows a regional border and the edge of a grassland. No planting records exist. The Swiss pines of the Smrekovec massif must retain their status as a dendrological site of natural interest.

The Swiss stone Pine (Pinus cembra L.) is an alpine species, fairly commonly occurring in the Alps and the Carpathians, close to the timberline. Natural sites of the Swiss stone pine in Poland are found exclusively in the Tatra Mountains, within the area of the Tatra National Park (TNP). In 2017, the health status of the needles of P. cembra was determined and their mycological analysis was carried out. As a result, 11 species of fungi were isolated from the needles showing disease symptoms, manifested by various shades of discoloration. The most frequently observed species was Fusarium oxysporum. It probably does not bring on disease symptoms, but may affect the development of other frequently isolated species (such as Sydowia polyspora, Lophodermium sp. and Lophodermium conigenum) that are pathogenic to Pinus spp.

Radial tree stem growth of Norway spruce (Picea abies (L.) H. Karst.), European beech (Fagus sylvatica L.), Scots pine (Pinus sylvestris L.), and stone pine (Pinus cembra L.) was monitored from 2012 to 2015 across sites in Austria with high-resolution dendrometers. Seasonal cumulative diameter increment was modeled using a hierarchical nonlinear mixed-effects model framework based on a logistic growth curve. In the dry and warm year 2015, the average annual diameter increment of 0.30 cm decreased by 50% on lower elevation sites and by 10% on higher elevation sites. In the cool and moist year 2014, Norway spruce achieved a higher annual diameter increment than European beech, whereas the opposite occurred in the dry and warm years 2013 and 2015. In the mixed beech–spruce stand, beech’s consumptive water-use strategy has obviously caused intensified stress for spruce in these drought periods. On higher elevation sites, Norway spruce reacted more sensitively to climate fluctuation compared with stone pine, but overall reactions were only weak. Productivity varied strongly depending on the social status of the tree, with dominant and intermediate trees suffering more from drought. As warming and drought lowers increment rates on lower elevation sites and as trees on higher elevation sites react less flexibly, productivity losses are expected for Austrian forests due to climate warming.

The ability of treeline conifers in the Central European Alps to cope with recent climate warming and increasing CO2 concentration is still poorly understood. We determined basal area increment (BAI) and tree ring stable carbon isotope ratios (δ13C) of Pinus cembra trees from 1925 through 2013. Stable isotope ratios and BAI were compared with leaf level gas exchange measurements carried out in situ between 1934 and 2012, and thus, provided new insights into long-term trends of tree-ring derived intrinsic water-use efficiency (iWUE). Mature P. cembra trees at treeline responded to increasing Ca and air temperature with a parallel increase in maximum net CO2 uptake rate at ambient CO2 (Amax) and tree-ring-derived intercellular CO2 partial pressure (Ci). Amax tripled and was positively correlated to BAI and Ci. The latter increased in parallel with ambient CO2 concentration and stomatal conductance. In contrast to the instantaneous gas exchange parameters, δ13C derived iWUE informs about the long-term changes in the carbon water relations. These data showed three changes in the iWUE chronosequences, which could be identified with different long term gas exchange patterns: (1) from stomatal controlled functioning from 1925 to 1981, to a situation where (2) both net CO2 fixation (A) and leaf conductance for water vapour (gw), responded to the environment from 1982 to 1997, and (3) back to a stomata controlled pattern over iWUE from 1998 onwards. This temporal pattern was also mirrored in leaf level gas exchange assessments, suggesting a parallel increase of A and gw of P. cembra at treeline during the last nine decades.

The high ambient ozone concentrations cause impairing effects on vegetation leading to plant injuries. The potential ozone uptake to vegetation through open stomata can be quantified using stomatal conductance measurements under the local environmental conditions. This study compares the ozone stomatal conductance to vegetation obtained with a modified Jarvis formula adopted from the Vegetation Manual of United Nations Economic Commission for Europe, and experimental field measurements’ data. The stomatal conductance was measured by a portable photosynthesis and gas exchange analyzer system LiCOR6400. The measurements were performed in the submontane environment of the High Tatra Mountains in Slovakia on Swiss pine (Pinus cembra), as a native species of the local flora. According to previous studies, Swiss pine is considered as an ozone-sensitive species. The modified Jarvis model for the ozone stomatal conductance is compared with the field measurements. The suitable parameterization of the modified Jarvis model for Swiss pine is obtained. The parameterization of stomatal conductance for Swiss pine in the local environment would help understand its specificity and similarity to other conifer species. In the case of using parameterization for a boreal coniferous from the Vegetation Manual of the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops, validation of the model with the measurements without temperature adjustment of the conifer chamber achieved a coefficient of determination of R2=0.75. This result is not in contradiction with the previous researches. With the optimal set of parameters, obtained in this paper, the Jarvis model reaches R2=0.85. The data suggest that Jarvis-type models with appropriate parameterization are applicable for stomatal conductance estimation for Pinus cembra when the measurements do not modify the temperature regime.