Spanish Pyrenees Research Articles

A farewell to glaciers: Ecosystem services loss in the Spanish Pyrenees

Glaciers are long-term freshwater reservoirs that contribute to the regulation of water availability throughout the year. In the Pyrenees mountain range, glaciers are predicted to disappear by the mid 21st century if current melting trends continue. The areas downstream from these glaciers have seen a gradual increase in water consumption since the 1980s, mainly due to the conversion of traditional crops to more water-demanding products, expansion of the irrigated agricultural area, and modernization of agricultural techniques that create incentives to spread water use. The steady increase of water consumption is not compatible with the predicted future scenario, where a reduced provision of water as an essential ecosystem service is expected, in particular during the dry summers. In this study, we present an up-to-date outlook on the evolution of the glaciers on the Spanish side of the Pyrenees. We then calculate the melting rate (in volume) of these glaciers in order to estimate their water contributions to their respective watersheds. These results are combined with existing data on water consumption for each watershed, and aiming to offer a more sustainable future for the local population, we propose a set of adaptive measures that have been implemented in other regions where water availability has gradually become an issue. These measures are focused on diversifying the most water-consuming activity in the region (agriculture) to enable a future compatible with the ecosystem services the region is able to provide.

An economic analysis of transhumance in the Central Spanish Pyrenees

The ecological and risk -management rationales for livestock mobility are well established. Yet, few studies evaluate the economic benefits and costs of maintaining or resuming mobile, extensive livestock production compared to sedentary or semi-extensive production. Here, we empirically evaluate pastoralists’ claims that transhumance, a specific type of long-distance herd mobility, is a more profitable system compared to semi-extensive production in the Central Spanish Pyrenees. Specifically, we use enterprise budget data from transhumant and semi-extensive operations to develop a baseline typical sheep operation budget. We then use partial budget analysis coupled with economic simulations to determine the conditions under which transhumance by truck or on foot becomes profitable relative to semi-extensive production. We find that transhumance by foot is more profitable than transhumance by truck and that relative profitability compared to semi-extensive production depends on operational scale, feed prices, and the lambing rates (productivity) of each system. Over all simulated scenarios, transhumance is more profitable 64–78% of the time. This analysis thus provides initial evidence of the economic rationality of transhumance under contemporary environmental and economic conditions, filling a notable gap in research on the economics of transhumance. Future research could expand the analysis to cattle operations and to other regions of Spain, assess the full social and environmental benefits and costs of transhumance, and evaluate the effects of exogenous factors like drought on production costs and profitability to determine if transhumance is an adaptive strategy under a changing climate. The analysis we present could be used as a basis to develop and pilot test interactive budgeting tools that support herder decision-making and planning under economic and environmental uncertainty.

Delta blue intensity vs. maximum density: A case study using Pinus uncinata in the Pyrenees

We explore the potential of the delta blue intensity (DBI) parameter as a proxy of past summer temperatures using a well replicated (85 trees) chronology of Pinus uncinata from upper treeline in the Spanish Pyrenees. Principal component analysis, correlation response function analysis and Superposed Epoch Analysis show definitively that the DBI data are indistinguishable to other MXD datasets in the region and that DBI expresses a similarly “pure” time-stable climate signal as MXD when compared to their RW counterparts. Calibration r2 values > 0.5 are attainable depending on period used. The signal strength of DBI data is weaker than MXD and behave more like RW data with ca. 19 trees being needed to attain an EPS value > 0.85. However, as the generation of DBI data is cheaper than MXD, this limitation is not deemed to be a serious issue. This pilot study suggests that robust reconstructions of past summer temperatures could be gained using DBI data at a much-reduced cost than relying on MXD. Future dendroclimatic efforts in the region therefore should focus on the measurement of this parameter and the expansion of the pinus ring-density network.

What do minerals in the feces of Bearded Vultures reveal about their dietary habits?

The diet of Bearded Vultures Gypaetus barbatus consists mainly of bones, which are completely digested in the gastrointestinal tract, unwanted bone minerals being discarded via the feces. Chemical analyses of feces therefore provide a noninvasive technique for studying the diet of this species. We analysed the inorganic and organic remains in feces collected from Bearded Vulture nests in the Spanish Pyrenees and discussed these results with the diet of individuals determined by video camera observations. Of the food items delivered to the nest, taxonomically 65% were bone fragments of Ovis/Capra spp. (range 56–75%) and anatomically 76% (74–81%) bones from the extremities, indicating a selective preference. At least 15% of the diet was meat based, mainly originating from small prey (e.g. small carnivores, birds). The fecal analyses show that calcium and phosphorus are the most abundant mineral constituents, accounting for 41.3–44.4% of the mineral part of the feces. Among the minor elements identified, the variation in the concentrations of iron, silicon and zinc suggest differences in food selection between territories, although this could be related to varying amounts of accidentally ingested soil particles present in the food. We found variation in the content of uric acid in the feces, ranging between 0.5 and 4.6%. Higher values of uric acid might be due to a more meat or marrow bone-based diet. However, no relationship was found between the amount of calcium and uric acid levels, suggesting that the metabolites of meat digestion (uric acid) and those of bone digestion (calcium) are not negatively correlated as expected. In conclusion, our chemical analyses of feces collected from the nests of Bearded Vultures confirm that their diet consists mainly of bone remains and that these bones are digested completely. However, the direct observations of the prey items delivered to the nest produced more detailed information than the chemical analyses.

Neoglaciation in the Spanish Pyrenees: a multiproxy challenge

Following the Holocene Thermal Maximum, dated between 11 and 6 ka, the Neoglacial period was one of the progressive, fluctuating cooling that peaked during the Little Ice Age (LIA). The almost total absence of glacial tills prior to the LIA in the Pyrenees forces recourse to a high variety of proxies, including lacustrine sediments, palynological records, dendroclimatology, ice cores from glaciers and caves, speleothems, historical documentation and glacial records. This has enabled us to identify several colder periods during the mid- and late-Holocene: (i) the first phase of the Neoglacial period occurred at some time around 6 ka; (ii) a glacial pulse immediately before 3.4 ka; (iii) a glacial re-advance during the Dark Ages, i.e., immediately before the Medieval Climate Anomaly, between the fourth and ninth centuries; and (iv) the Little Ice Age, which started at the beginning of the fourteenth century and finished in the mid-nineteenth century. During the LIA, there was remarkable climate variability, with two, and probably three, glacial pulses, mainly between 1620 and 1715 and in the first half of the nineteenth century. Of all of the Holocene cold periods, most of the European paleoclimatic records coincide on the occurrence of the LIA. For the remaining Holocene cold periods, European records show high variability and uncertainty, particularly for the onset of the Neoglacial, although the phases of glacial pulses in the Pyrenees broadly coincide with those identified in the Alps and northern Europe.

Forecasting Forest Vulnerability to Drought in Pyrenean Silver Fir Forests Showing Dieback

Forest dieback is manifested as widespread loss of tree vigour, growth decline and high mortality rates. Forest dieback is becoming increasingly frequent and extended, particularly in drought-prone regions. This is the case of the south-western Spanish Pyrenees, where keystone species such as Silver fir reach their xeric and southern distribution limits. While dieback of this species has been widely documented in this area, we still lack methodologies to forecast the vulnerability of these forests in response to increasing drought stress so as to anticipate their potential dieback in the future. Here we study multiple features of Silver fir forest and trees to evaluate whether previous growth rates and their growth trends are valid predictors of forest dieback. Further, we validate our methodology revisiting two Silver fir sites sampled two decades ago. The defoliation degree was strongly related with radial growth, and growth trends differed between moderately to highly defoliated trees and non-defoliated trees. Forests showing dieback, i.e. those in which 25% of the sampled trees showing defoliation > 50%, were located at low elevation and received less rainfall in summer than forests showing no dieback. Trees showing high defoliation presented lower growth rates than non-defoliated trees. Moreover, we ratified that defoliation has increased considerably over the last two decades in one of the two revisited sites, but we were unable to accurately forecast growth trends in both sites, particularly in the site not showing dieback. The retrospective assessment of growth rates and trends offers valuable information on the vulnerability of Silver fir trees to drought. However, we are still far from being able to forecast the vulnerability of Silver fir forest to increasing drought. A systematic monitoring of growth across a wide tree-ring network of sites might provide valuable information to advance in this direction.

Evolution of Hay Meadows between 1956, 1986, and 2016 and Its Relation to the Characteristics and Location of the Parcels in the Valley of the River Esera (Pyrenees, Spain)

The uses of the agricultural surface of hay meadows and crops of the mountain areas of the Spanish central Pyrenees are subject to constant transformations. This paper addresses the changes produced in the hay meadows of the Ésera river valley of the central Pyrenees (Spain) regarding the surface and the agronomic and topographic characteristics of the parcels between 1956–1986 and 1986–2016. The cartographed area is 5226 hectares, of which 1941 hectares correspond to 6416 polygons that have been mowed or cultivated on one of the three reference dates. In the period 1956–1986, there is a reduction in the agricultural area of meadows and crops (13.59%) in favor of pastures, forest, urbanized land, and water reservoirs. The surface of the meadows increases to 301.58%, to the detriment of the crops, until almost their disappearance. Between 1986 and 2016, the area of meadows is reduced to 59.11%, and the area of pastures, forests, and urbanized land increases. The topographic characteristics of the parcels with respect to surface, altitude, slope, width, and terracing and distance to the communication routes determine mechanized access and management and discriminate the transformation to pasture and forest.

Variable effects of forest canopies on snow processes in a valley of the central Spanish Pyrenees

AbstractSnowpacks and forests have complex interactions throughout the large range of altitudes where they co‐occur. However, there are no reliable data on the spatial and temporal interactions of forests with snowpacks, such as those that occur in nearby areas that have different environmental conditions and those that occur during different snow seasons. This study monitored the interactions of forests with snowpacks in four forest stands in a single valley of the central Spanish Pyrenees during three consecutive snow seasons (2015/2016, 2016/2017 and 2017/2018). Daily snow depth data from time‐lapse cameras were compared with snow data from field surveys that were performed every 10–15 days. These data thus provided information on the spatial and temporal changes of snow–water equivalent (SWE). The results indicated that forest had the same general effects on snowpack in each forest stand and during each snow season. On average, forest cover reduced the duration of snowpack by 17 days, reduced the cumulative SWE of the snowpack by about 60% and increased the spatial heterogeneity of snowpack by 190%. Overall, forest cover reduced SWE total accumulation by 40% and the rate of SWE accumulation by 25%. The forest‐mediated reduction of the accumulation rate, in combination with the occasional forest‐mediated enhancement of melting rate, explained the reduced duration of snowpacks beneath forest canopies. However, the magnitude and timing of certain forest effects on snowpack had significant spatial and temporal variations. This variability must be considered when selecting the location of an experimental site in a mountainous area, because the study site should be representative of surrounding areas. The same considerations apply when selecting a time period for study.

Effects of active and passive land use management after cropland abandonment on water and vegetation dynamics in the Central Spanish Pyrenees

The Mediterranean mountains have been subject to significant land abandonment process during the second half of the 20th century. The subsequent natural revegetation following abandonment in rural areas has been widely documented to have substantial implications on the hydrological cycle and the vegetation. The Spanish Pyrenees are one of the most affected areas by these land transformations which could threaten their importance for water supply and agricultural activities in the downstream lowland areas.Land managers as well as scientists around the world have taken different positions on how to deal with these land use changes. Some are in favor of active management (AM) (i.e. density reduction) while others are supporting passive management (PM) (letting the process of revegetation continue). This study aims to investigate the implication of AM and PM on hydrological and vegetation dynamics under different climate trajectories in a representative abandoned cropland catchment in the Central Spanish Pyrenees. A coupled ecohydrologic model is used to estimate the post management response of streamflow (STR), evapotranspiration (ET), soil saturation deficit (SD) and plant carbon (PC) following shrub clearing. Clearing increased annual STR by 16%, while ET and SD decreased by around −9% and −6% respectively during the first year after management with changes to monthly flows. These changes to water regimes may be even higher in wetter years. Over a 10-years period of vegetation recovery annual STR increased between 7.1% and 24.2%, while annual ET and SD decreased between −2.6% to −8.7% and −2.7% to −6% respectively due to shrub clearing, with the highest changes occurring in the first three years of AM. On the effect of climate change, our results show that a 2 °C increase in temperature could reduce AM effects on water regimes and accelerate the recovery of PC given averaged rainfall conditions.

A massacre of early Neolithic farmers in the high Pyrenees at Els Trocs, Spain

Violence seems deeply rooted in human nature and an endemic potential for such is today frequently associated with differing ethnic, religious or socio-economic backgrounds. Ethnic nepotism is believed to be one of the main causes of inter-group violence in multi-ethnic societies. At the site of Els Trocs in the Spanish Pyrenees, rivalling groups of either migrating early farmers or farmers and indigenous hunter-gatherers collided violently around 5300 BCE. This clash apparently resulted in a massacre of the Els Trocs farmers. The overkill reaction was possibly triggered by xenophobia or massive disputes over resources or privileges. In the present, violence and xenophobia are controlled and sanctioned through social codes of conduct and institutions. So that, rather than representing an insurmountable evolutionary inheritance, violence and ethnic nepotism can be overcome and a sustainable future achieved through mutual respect, tolerance and openness to multi-ethnic societies.

Nocturnal flights by Bearded Vultures Gypaetus barbatus detected for the first-time using GPS and accelerometer data

ABSTRACT Capsule: We document previously undescribed nocturnal flight behaviour by Bearded Vultures Gypaetus barbatus using a combination of accelerometer and global positioning system (GPS) information. Aims: To study the nocturnal flight activity of the Bearded Vulture and determine whether nocturnal flights could be linked to foraging behaviour. Methods: We used both accelerometer and GPS location data of 11 Bearded Vultures in the Spanish Pyrenees along with 88 carcasses monitored with camera traps. Results: Over half (55%, n = 11) of the individuals tracked were recorded flying between 0.7 and 6.1 km on at least 19 different nights, including 37% that occurred when less than 20% of the moon was illuminated. Bearded Vultures displayed feeding activity in only 8.2% of the 146 feeding events existing during the hour after dawn and the hour before dusk. Conclusions: Our findings suggest that foraging benefits do not explain the nocturnal flights. Disturbances or adverse weather conditions may result in the abandonment of an overnight roosting site. This could also explain why individuals recovered in the field showed impact injuries.

The NEXT experiment for neutrinoless double beta decay searches

The goal of the NEXT experiment is the observation of the neutrinoless double beta decay in 136Xe using a gaseous xenon TPC with electroluminescent amplification and specialized photodetector arrays for calorimetry and tracking. After a prototyping period (2009-2014) where the technique was demonstrated, the Collaboration has completed the construction and started the operation of its first phase (NEXT-White or NEW) in the Laboratorio Subterraneo de Canfranc, in the Spanish Pyrenees, with the objectives of measuring in-situ the NEXT background model and the two-neutrino mode of the double beta decay under a radiopure regime. After running NEW, the Collaboration will operate a bigger detector, NEXT-100, which will look for the neutrinoless decay mode.

Injury Prevention: Freestylers' Awareness of FIS Code of Conduct for Snow Parks.

The objectives of the present study were to assess general perceptions of safety in snow parks (SPs), general knowledge of rules existence, and both active and passive awareness of the International Ski Federation (FIS) rules contained in its Code of Conduct for SPs in order to define target groups for injury prevention-specific education interventions. Data were drawn from 436 freestylers randomly interviewed. The study was conducted during the 2018–2019 winter season in the SP of a major winter resort located in the Spanish Pyrenees. A questionnaire assessing personal data (gender, age, gear used, self-reported skill, and frequency of use), general perceptions on safety, general request for rules, and awareness of existing rules in SPs was developed. Chi-square goodness-of-fit tests were used to compare characteristics between groups. It was revealed, for accident prevention purposes, a concerning general lack of knowledge of existing rules in SPs (63% of participants ignored them). Risk-inducing situations that could result in severe injuries, such as familiarity with the right progression in choosing features and/or stunts or with safety equipment, were largely assessed incorrectly (94% and 70% of participants, respectively). Appropriate intuitive behavior increases with experience: youths and beginners are less able to implement FIS rules than more experienced freestylers.

Snowboarders' Knowledge of the FIS Rules for Conduct on Ski Slopes.

The objective of the present study is to assess snowboarders’ general perceptions of safety and knowledge of existing rules and both active and passive knowledge of the International Ski Federation (FIS) regulations in order to contribute to defining target groups for specific educational interventions in the field of injury prevention. Data were drawn from random interviews conducted with 918 snowboarders during the 2017–2018 winter season at five ski resorts located in the Spanish Pyrenees. To collect the data, a questionnaire assessing personal characteristics (gender, age, origin, and self-reported skill), general perception of safety, general request for rules, and knowledge of existing rules was used. Pearson’s Chi-squared tests were performed to compare characteristics between groups. The study revealed, for accident prevention purposes, a concerning lack of general knowledge of existing rules. Risk-inducing situations that could result in severe injuries were largely assessed incorrectly. The appropriate intuitive behavior increases with age and experience: youths and beginners are less able to implement the FIS rules than older and more experienced snowboarders. Stakeholders, such as parents, ski resorts, clubs or schools, should direct educational efforts at high-risk groups. Further research is needed to determine the causal relation between snowboard-related injuries and disregard of FIS rules.

Detecting snow-related signals in radial growth of Pinus uncinata mountain forests

Climate warming is responsible for observed reduction in snowpack depth and an earlier and faster melt-out in many mountains of the Northern Hemisphere. Such changes in mountain hydroclimate could negatively affect productivity and tree growth in high-elevation forests, but few studies have investigated how and where recent warming trends and changes in snow cover influence forest growth. A network comprising 36 high-elevation Pinus uncinata forests was sampled in the NE Iberian Peninsula, mainly across the Spanish Pyrenees, using dendrochronology to relate tree radial growth to a detailed air temperature and snow depth data. Radial growth was negatively influenced by a longer winter snow season and a higher late-spring snowpack depth. Notably, the effect of snow on tree growth was found regardless the widely reported positive effect of growing-season air temperatures on P. uncinata growth. No positive influence of moisture from spring snowmelt on annual growth of P. uncinata was detected in sampled forests. Tall trees showed a lower growth responsiveness to snow than small trees. Decreasing trends in winter and spring snow depths were detected at most Pyrenean forests, suggesting that the growth of high-elevation P. uncinata forests can beneficiate for a shallower and of shorter duration snowpack associated with warmer conditions. However, water-limited sites located on steep slopes or on rocky substrates, with poor soil-water holding capacity, could experience drought stress because of early depleted snow-related soil moisture.

Evidence of a fixed polymorphism of one‐year and two‐year larval growth in the myrmecophilous butterfly Maculinea rebeli

Abstract Maculinea (= Phengaris) species of butterfly have complex life‐styles in which the larvae feed briefly on specific foodplants before entering the final instar, after which they live as social parasites within Myrmica ant colonies and acquire 98–99% of their ultimate biomass by either preying on ant brood (predatory species) or being fed by worker ants (cuckoo species). Cuckoo species demonstrate two growth forms, whereby some individuals develop to pupate in 11 months and others remain 23 months in the nest, a strategy that in theory represents the most efficient exploitation of resources within Myrmica societies. Early studies suggested that development rates in Maculinea rebeli (referred to by other authors as the xerophilous form of Maculinea alcon) were not plastic but represented an unusual fixed polymorphism, in which eggs were genetically predetermined as 1‐ or 2‐year larvae. We tested this idea in lab experiments using M. rebeli from the French Hautes‐Alpes, with these results: (i) the growth strategy of every individual larva is pre‐determined by the mother either genetically or, less probably, during oogenesis. (ii) Intra‐nest competition and host fitness affects survival and growth but does not influence the inherent growth strategy. (iii) The ratio of 1‐ and 2‐year developing larvae is initially about 50:50, although differential survival in crowded nests may alter the ratio of surviving individuals. (iv) All females tested laid eggs that hatched into both 1‐ or 2‐year developers. (v) Growth patterns vary between different regions. Larvae from the Spanish Pyrenees initially grow less than those from the Alps, with a smaller initial differentiation between the size classes.

The episodic rise, net growing rate and kinematics of radial faults of the Salinas de Oro diapir using paleoseismological techniques (NE Spain). Salt upwelling versus karstic subsidence

This paper explores the use of trenching and paleoseismological techniques to determine salt flow rates into a salt diapir for the first time in the literature. The Salinas de Oro diapir, located in the northern Spanish Pyrenees, is an oval-shaped Triassic-salt stock that extends vertically for ≫7 km down to the Paleozoic basement. Salt dissolution subsidence and diapir growth are coeval active processes. Karstification is responsible for the development of large sinkholes, a thick caprock and the monocline folding and ring faulting of the Cretaceous and Early Tertiary limestone rim. The evaporite karstic aquifer discharges high-concentration water of up to 137 g/l of total dissolved solids and a conductivity over 200 mS/cm into the Salado Creek, which drains the diapir top. The salinity monitoring of this drainage provides a maximum karstic surface lowering rate of around 2.8 mm/yr. Salt upwelling has caused the 150 m uplift of the annular limestone escarpment and the development of ≫3000 m long radial grabens with up to 90 m of vertical offset that disrupt drainages, displace Quaternary deposits and overprint concentric faults. The 260 cm drag folding of lacustrine facies exposed in a 42 m long and 6.5 m deep trench due to the creep motion of the western radial fault of Azanza Graben yielded a minimum short-term uplift slip rate of 1.75 mm/yr for the last 1485 years and provides a minimum salt supply rate of over 5 mm/yr considering karstification lowering. This value that is several hundred times higher than average, evidence the discontinuous growth of Salinas de Oro diapir.

Supercritical-flow Deposits and Their Distribution in a Submarine Channel System, Middle Eocene, Ainsa Basin, Spanish Pyrenees

Abstract Studies of supercritical-flow deposits (SFDs) and their spatial distribution in ancient deep-water systems should provide an additional tool to improve the understanding of the flow dynamics during deposition and the architecture of sandbodies. Outcrop recognition of SFDs in ancient deep-marine environments remains poorly documented, although their study dates back to the 1970s. This paper focusses on the criteria for recognizing SFDs and their distribution in three selected depositional environments from an ancient mid-lower slope to a proximal-basin floor setting in the middle Eocene Ainsa Basin, Spanish Pyrenees. From field observations, six facies associations interpreted as related to supercritical flow are defined. These facies associations are grouped in two categories. The first group includes facies associations related to erosional coarse-grained supercritical-flow bedforms related to meter and centimeter-scale scours and backfilling structures interpreted as large-scale cyclic steps or small-scale cyclic steps, respectively. Erosional coarse-grained supercritical bedforms are observed mainly in relatively high-gradient slopes and relatively confined settings. The second group of facies associations are related to depositional fine-grained supercritical-flow bedforms associated with upflow-dipping sandstone lenses, upflow-stacked wavy bedforms, upflow-stacked sigmoidal bedforms, and plane beds, interpreted as unstable and stable antidunes and upper-flow-regime plane beds. Depositional fine-grained supercritical-flow bedforms are observed mainly in relatively unconfined settings such as lower-slope, break-of-slope and proximal basin-floor environments. Two main SFD trends were observed in the Ainsa Basin in: (i) an axial-lateral direction, showing a decrease in SFDs from channel axis to channel margin, and (ii) a longitudinal proximal–distal direction, showing an increase in SFDs from the Gerbe System (mid-slope environment), to the Banastón System (proximal basin-floor environment), to the Ainsa System (lower-slope environment). From this study, two parameters are recognized as likely playing an important role on whether a flow is under supercritical or subcritical conditions: (i) confinement of the sandbodies, and (ii) slope gradient.

GEOMATIC METHODS APPLIED TO THE CHANGE STUDY OF THE LA PAÚL ROCK GLACIER, SPANISH PYRENEES

Abstract. Rock glaciers are one of the most important features of the mountain permafrost in the Pyrenees. La Paúl is an active rock glacier located in the north face of the Posets massif in the La Paúl glacier cirque (Spanish Pyrenees). This study presents the preliminary results of the La Paúl rock glacier monitoring works carried out through two geomatic technologies since 2013: Global Navigation Satellite System (GNSS) receivers and Terrestrial Laser Scanning (TLS) devices. Displacements measured on the rock glacier surface have demonstrated both the activity of the rock glacier and the utility of this equipment for the rock glaciers dynamic analysis. The glacier has exhibited the fastest displacements on its west side (over 35 cm yr−1), affected by the Little Ice Age, and frontal area (over 25 cm yr−1). As an indicator of permafrost in marginal environments and its peculiar morphology, La Paúl rock glacier encourages a more prolonged study and to the application of more geomatic techniques for its detailed analysis.

Limited capacity of tree growth to mitigate the global greenhouse effect under predicted warming

It is generally accepted that animal heartbeat and lifespan are often inversely correlated, however, the relationship between productivity and longevity has not yet been described for trees growing under industrial and pre-industrial climates. Using 1768 annually resolved and absolutely dated ring width measurement series from living and dead conifers that grew in undisturbed, high-elevation sites in the Spanish Pyrenees and the Russian Altai over the past 2000 years, we test the hypothesis of grow fast—die young. We find maximum tree ages are significantly correlated with slow juvenile growth rates. We conclude, the interdependence between higher stem productivity, faster tree turnover, and shorter carbon residence time, reduces the capacity of forest ecosystems to store carbon under a climate warming-induced stimulation of tree growth at policy-relevant timescales.