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David Frank - One of the best experts on this subject based on the ideXlab platform.
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improved Tree Ring archives will support earth system science
Nature Ecology and Evolution, 2017Co-Authors: Flurin Babst, Benjamin Poulter, Paul Bodesheim, Miguel D Mahecha, David FrankAbstract:A steep decline in archiving could make large Tree-Ring datasets irrelevant. But increased spatiotemporal coverage, the addition of novel parameters at sub-annual resolution, and integration with other in situ and remote Earth observations will elevate Tree-Ring data as an essential component of global-change research.
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A Tree-Ring perspective on the terrestrial carbon cycle
Oecologia, 2014Co-Authors: Flurin Babst, David Frank, Benjamin Poulter, M. Ross Alexander, Paul Szejner, Olivier Bouriaud, Stefan Klesse, John Roden, Philippe Ciais, David J. P. MooreAbstract:Tree-Ring records can provide valuable information to advance our understanding of contemporary terrestrial carbon cycling and to reconstruct key metrics in the decades preceding monitoRing data. The growing use of Tree Rings in carbon-cycle research is being facilitated by increasing recognition of reciprocal benefits among research communities. Yet, basic questions persist regarding what Tree Rings represent at the ecosystem level, how to optimally integrate them with other data streams, and what related challenges need to be overcome. It is also apparent that considerable unexplored potential exists for Tree Rings to refine assessments of terrestrial carbon cycling across a range of temporal and spatial domains. Here, we summarize recent advances and highlight promising paths of investigation with respect to (1) growth phenology, (2) forest productivity trends and variability, (3) CO_2 fertilization and water-use efficiency, (4) forest disturbances, and (5) comparisons between observational and computational forest productivity estimates. We encourage the integration of Tree-Ring data: with eddy-covariance measurements to investigate carbon allocation patterns and water-use efficiency; with remotely sensed observations to distinguish the timing of cambial growth and leaf phenology; and with forest inventories to develop continuous, annually-resolved and long-term carbon budgets. In addition, we note the potential of Tree-Ring records and derivatives thereof to help evaluate the performance of earth system models regarding the simulated magnitude and dynamics of forest carbon uptake, and inform these models about growth responses to (non-)climatic drivers. Such efforts are expected to improve our understanding of forest carbon cycling and place current developments into a long-term perspective.
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kinetics of tracheid development explain conifer Tree Ring structure
New Phytologist, 2014Co-Authors: Henri E Cuny, Cyrille B K Rathgeber, David Frank, Patrick Fonti, Meriem FournierAbstract:Summary � Conifer Tree Rings are generally composed of large, thin-walled cells of light earlywood followed by narrow, thick-walled cells of dense latewood. Yet, how wood formation processes and the associated kinetics create this typical pattern remains poorly understood. � We monitored Tree-Ring formation weekly over 3 yr in 45 Trees of three conifer species in France. Data were used to model cell development kinetics, and to attribute the relative importanceofthedurationandrateofcellenlargementandcellwalldepositiononTree-Ringstructure. � Cell enlargement duration contributed to 75% of changes in cell diameter along the Tree Rings. Remarkably, the amount of wall material per cell was quite constant along the Rings. Consequently, and in contrast with widespread belief, changes in cell wall thickness were not principally attributed to the duration and rate of wall deposition (33%), but rather to the changes in cell size (67%). Cell enlargement duration, as the main driver of cell size and wall thickness, contributed to 56% of wood density variation along the Rings. � This mechanistic framework now forms the basis for unraveling how environmental stresses trigger deviations (e.g. false Rings) from the normal Tree-Ring structure.
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Forward modelling of Tree-Ring width and comparison with a global network of Tree-Ring chronologies
Climate of the Past, 2014Co-Authors: Petra Breitenmoser, Stefan Brönnimann, David FrankAbstract:Abstract. We investigate relationships between climate and Tree-Ring data on a global scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of Tree-Ring width formation. The VSL model requires as inputs only latitude, monthly mean temperature, and monthly accumulated precipitation. Hence, this simple, process-based model enables Ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated Tree Rings to monthly climate conditions obtained from the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL model performance by examining the relations between simulated and observed growth at 2287 globally distributed sites, (b) indentify optimal growth parameters found duRing the model calibration, and (c) to evaluate the potential of the VSL model as an observation operator for data-assimilation-based reconstructions of climate from Tree-Ring width. The assessment of the growth-onset threshold temperature of approximately 4–6 °C for most sites and species using a Bayesian estimation approach complements other studies on the lower temperature limits where plant growth may be sustained. Our results suggest that the VSL model skilfully simulates site level Tree-Ring series in response to climate forcing for a wide range of environmental conditions and species. Spatial aggregation of the Tree-Ring chronologies to reduce non-climatic noise at the site level yielded notable improvements in the coherence between modelled and actual growth. The resulting distinct and coherent patterns of significant relationships between the aggregated and simulated series further demonstrate the VSL model's ability to skilfully capture the climatic signal contained in Tree-Ring series. Finally, we propose that the VSL model can be used as an observation operator in data assimilation approaches to reconstruct past climate.
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spectral biases in Tree Ring climate proxies
Nature Climate Change, 2013Co-Authors: Jan Esper, David Frank, Stefan Brönnimann, Jorg Franke, Christoph C RaibleAbstract:Seamless quantification of past and present climate variability is needed to understand the Earth’s climate well enough to make accurate predictions for the future. This study addresses whether Tree-Ring-dominated proxy data properly represent the frequency spectrum of true climate variability. The results challenge the validity of detection and attribution investigations based on these data.
Neil Pederson - One of the best experts on this subject based on the ideXlab platform.
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a late holocene subfossil atlantic white cedar Tree Ring chronology from the northeastern united states
Quaternary Science Reviews, 2020Co-Authors: Jessie K. Pearl, Charlotte L. Pearson, Neil Pederson, Edward R Cook, Kevin J Anchukaitis, Jeffrey P Donnelly, Mary Lardie C Gaylord, Ann P Mcnichol, George L ZimmermannAbstract:Abstract Tree-Rings provide precise annually dated climate information, but their application can be limited by the relatively short lifespan of many Trees. To overcome this limitation, Tree-Ring records can be extended over longer time periods by connecting living Trees with older “sub-fossil” Trees, which can provide information on longer timescales throughout the Holocene. These long chronologies are proxy records of past climate, provide precise chronological information for extreme events, and give insight into the range of natural climate variability prior to the instrumental period. In the densely populated northeastern United States, few Tree-Ring records are longer than 500 years, and there are no millennial-length Tree-Ring chronologies for the region. Here, we use a combination of standard dendrochronological and radiocarbon techniques, including use of the 774 CE radiocarbon excursion, to generate an absolutely dated 2500 year-long Tree Ring record from living, archaeological, and subfossil Atlantic white cedar (Chamaecyparis thyoides) found in the coastal northeastern United States. Our chronology demonstrates the potential to develop multi-millennial Chamaecyparis thyoides Tree-Ring records to address previously unanswered questions regarding late Holocene hydroclimate, extreme events, and temperature variability in New England.
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Tree Ring isotopes capture interannual vegetation productivity dynamics at the biome scale
Nature Communications, 2019Co-Authors: Mathieu Levesque, Laia Andreuhayles, William K Smith, Park A Williams, Martina L Hobi, Brady W Allred, Neil PedersonAbstract:Historical and future trends in net primary productivity (NPP) and its sensitivity to global change are largely unknown because of the lack of long-term, high-resolution data. Here we test whether annually resolved Tree-Ring stable carbon (δ13C) and oxygen (δ18O) isotopes can be used as proxies for reconstructing past NPP. Stable isotope chronologies from four sites within three distinct hydroclimatic environments in the eastern United States (US) were compared in time and space against satellite-derived NPP products, including the long-term Global Inventory Modeling and Mapping Studies (GIMMS3g) NPP (1982–2011), the newest high-resolution Landsat NPP (1986–2015), and the Moderate Resolution Imaging Spectroradiometer (MODIS, 2001–2015) NPP. We show that Tree-Ring isotopes, in particular δ18O, correlate strongly with satellite NPP estimates at both local and large geographical scales in the eastern US. These findings represent an important breakthrough for estimating interannual variability and long-term changes in terrestrial productivity at the biome scale. Historical and future trends in net primary productivity (NPP) and its sensitivity to global change are largely unknown because of the lack of long-term, high-resolution data. Here the authors show that Tree-Ring isotopes can be used for inferRing interannual variability and long-term changes in NPP.
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Preface: Tree-Ring Studies in New York State: Past and present [A Tree-Ring Research Special Issue]
Tree-Ring Research, 2014Co-Authors: David J. Barclay, Neil Pederson, Carol B. GriggsAbstract:Abstract New York State (NYS) has a long and significant history of Tree-Ring research. Some of the earliest dendroarchaeological and dendroclimatic work in eastern North America was done in NYS, and 1970s studies in Hudson Valley in the east of the state were important for demonstrating that drought records could be reconstructed from Trees growing in humid environments. Some recent work in NYS is described in this issue of Tree-Ring Research, including Tree-Ring dating and provenancing of a boat in New York City, dendroarchaeological studies in a town in northeastern NYS, dendrogeomorphological work in central NYS, and a dendroclimatic investigation of two range-margin Juniperus species growing on alvars. The last of the five NYS papers in this issue provides a personal historical perspective on the beginnings of drought reconstructions in the Hudson Valley. There is considerable potential for future work in New York with extension of existing studies and work in new areas and with new Tree species.
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a Tree Ring based reconstruction of delaware river basin streamflow using hierarchical bayesian regression
Journal of Climate, 2013Co-Authors: Naresh Devineni, Neil Pederson, Upmanu Lall, Edward R CookAbstract:A hierarchical Bayesian regression model is presented for reconstructing the average summer streamflow at five gauges in the Delaware River basin using eight regional Tree-Ring chronologies. The model provides estimates of the posterior probability distribution of each reconstructed streamflow series consideRing parameter uncertainty. The vectors ofregressioncoefficientsaremodeled asdraws froma commonmultivariate normal distribution with unknown parameters estimated as part of the analysis. This leads to a multilevel structure.Thecovariancestructureofthestreamflowresidualsacross sitesis explicitlymodeled. Theresulting partial pooling of information across multiple stations leads to a reduction in parameter uncertainty. The effect of no pooling and full pooling of station information, as end points of the method, is explored. The nopooling modelconsiders independent estimationof the regressioncoefficientsfor each streamflow gaugewith respect to each Tree-Ring chronology. The full-pooling model considers that the same regression coefficients apply across all streamflow sites for a particular Tree-Ring chronology. The cross-site correlation of residuals is modeled in all cases. Performance on metrics typically used by Tree-Ring reconstruction experts, such as reduction of error, coefficient of efficiency, and coverage rates under credible intervals is comparable to, or better, for the partial-pooling model relative to the no-pooling model, and streamflow estimation uncertainty is reduced. Long record simulations from reconstructions are used to develop estimates of the probability of duration and severity of droughts in the region. Analysis of monotonic trends in the reconstructed drought events do not reject the null hypothesis of no trend at the 90% significance over 1754‐2000.
Charlotte L. Pearson - One of the best experts on this subject based on the ideXlab platform.
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secuRing timelines in the ancient mediterranean using multiproxy annual Tree Ring data
Proceedings of the National Academy of Sciences of the United States of America, 2020Co-Authors: Charlotte L. Pearson, Matthew W Salzer, Lukas Wacker, Peter W Brewer, Adam Sookdeo, Peter Ian KuniholmAbstract:Calendar-dated Tree-Ring sequences offer an unparalleled resource for high-resolution paleoenvironmental reconstruction. Where such records exist for a few limited geographic regions over the last 8,000 to 12,000 years, they have proved invaluable for creating precise and accurate timelines for past human and environmental interactions. To expand such records across new geographic territory or extend data for certain regions further backward in time, new applications must be developed to secure “floating” (not yet absolutely dated) Tree-Ring sequences, which cannot be assigned single-calendar year dates by standard dendrochronological techniques. This study develops two approaches to this problem for a critical floating Tree-Ring chronology from the East Mediterranean Bronze–Iron Age. The chronology is more closely fixed in time using annually resolved patterns of 14C, modulated by cosmic radiation, between 1700 and 1480 BC. This placement is then tested using an anticorrelation between calendar-dated Tree-Ring growth responses to climatically effective volcanism in North American bristlecone pine and the Mediterranean Trees. Examination of the newly dated Mediterranean Tree-Ring sequence between 1630 and 1500 BC using X-ray fluorescence revealed an unusual calcium anomaly around 1560 BC. While requiRing further replication and analysis, this anomaly merits exploration as a potential marker for the eruption of Thera.
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New frontiers in Tree-Ring research:
The Holocene, 2020Co-Authors: Jessie K. Pearl, John R Keck, William Tintor, Liliana Siekacz, Hannah M. Herrick, Matthew D. Meko, Charlotte L. PearsonAbstract:From its inception as a scientific discipline, Tree-Ring research has been used as a trans-disciplinary tool for dating and environmental reconstruction. Tree-Ring chronologies in some regions exte...
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a late holocene subfossil atlantic white cedar Tree Ring chronology from the northeastern united states
Quaternary Science Reviews, 2020Co-Authors: Jessie K. Pearl, Charlotte L. Pearson, Neil Pederson, Edward R Cook, Kevin J Anchukaitis, Jeffrey P Donnelly, Mary Lardie C Gaylord, Ann P Mcnichol, George L ZimmermannAbstract:Abstract Tree-Rings provide precise annually dated climate information, but their application can be limited by the relatively short lifespan of many Trees. To overcome this limitation, Tree-Ring records can be extended over longer time periods by connecting living Trees with older “sub-fossil” Trees, which can provide information on longer timescales throughout the Holocene. These long chronologies are proxy records of past climate, provide precise chronological information for extreme events, and give insight into the range of natural climate variability prior to the instrumental period. In the densely populated northeastern United States, few Tree-Ring records are longer than 500 years, and there are no millennial-length Tree-Ring chronologies for the region. Here, we use a combination of standard dendrochronological and radiocarbon techniques, including use of the 774 CE radiocarbon excursion, to generate an absolutely dated 2500 year-long Tree Ring record from living, archaeological, and subfossil Atlantic white cedar (Chamaecyparis thyoides) found in the coastal northeastern United States. Our chronology demonstrates the potential to develop multi-millennial Chamaecyparis thyoides Tree-Ring records to address previously unanswered questions regarding late Holocene hydroclimate, extreme events, and temperature variability in New England.
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Olive Tree-Ring problematic dating: a comparative analysis on Santorini (Greece)
PloS one, 2013Co-Authors: Paolo Cherubini, Charlotte L. Pearson, Turi Humbel, Hans Beeckman, Holger Gärtner, David Mannes, Werner Schoch, Roberto Tognetti, Simcha Lev-yadunAbstract:Olive Trees are a classic component of Mediterranean environments and some of them are known historically to be very old. In order to evaluate the possibility to use olive Tree-Rings for dendrochronology, we examined by various methods the reliability of olive Tree-Rings identification. Dendrochronological analyses of olive Trees growing on the Aegean island Santorini (Greece) show that the determination of the number of Tree-Rings is impossible because of intra-annual wood density fluctuations, variability in Tree-Ring boundary structure, and restriction of its cambial activity to shifting sectors of the circumference, causing the Tree-Ring sequences along radii of the same cross section to differ.
Peter Trimborn - One of the best experts on this subject based on the ideXlab platform.
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a stable isotope Tree Ring timescale of the late glacial holocene boundary
Nature, 1991Co-Authors: Bernd Becker, Bernd Kromer, Peter TrimbornAbstract:LATE Glacial and Holocene Tree-Ring chronologies, like deep-sea sediments or polar ice cores, contain information about past environments. Changes in Tree-Ring growth rates can be related to past climate anomalies and changes in the isotope composition of Tree-Ring cellulose reflect changes in the composition of the atmosphere and the hydrosphere. We have established a 9,928-year absolutely dated dendrochronological record of Holocene oak (Quercus robur, Quercus petraea)—and a 1,604-year floating Late Glacial and Early Holocene chronology of pine (Pinus sylvestris) from subfossil Tree remnants deposited in alluvial terraces of south central European rivers. The pine sequence provides records of dendro-dated 14C, 13C and 2H patterns for the late Younger Dryas and the entire Preboreal (10,100–9,000 yr BP). Through the use of dendrochronology, radiocarbon age calibration and stable isotope analysis, we suggest that the Late Glacial/Holocene transition may be identified and dated by 13C and 2H Tree-Ring chronologies.
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A stable-isotope Tree-Ring timescale of the Late Glacial/Holocene boundary
Nature, 1991Co-Authors: Bernd Becker, Bernd Kromer, Peter TrimbornAbstract:LATE Glacial and Holocene Tree-Ring chronologies, like deep-sea sediments or polar ice cores, contain information about past environments. Changes in Tree-Ring growth rates can be related to past climate anomalies and changes in the isotope composition of Tree-Ring cellulose reflect changes in the composition of the atmosphere and the hydrosphere. We have established a 9,928-year absolutely dated dendrochronological record of Holocene oak (Quercus robur, Quercus petraea)—and a 1,604-year floating Late Glacial and Early Holocene chronology of pine (Pinus sylvestris) from subfossil Tree remnants deposited in alluvial terraces of south central European rivers. The pine sequence provides records of dendro-dated 14C, 13C and 2H patterns for the late Younger Dryas and the entire Preboreal (10,100–9,000 yr BP). Through the use of dendrochronology, radiocarbon age calibration and stable isotope analysis, we suggest that the Late Glacial/Holocene transition may be identified and dated by 13C and 2H Tree-Ring chronologies.
Jan Esper - One of the best experts on this subject based on the ideXlab platform.
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spectral biases in Tree Ring climate proxies
Nature Climate Change, 2013Co-Authors: Jan Esper, David Frank, Stefan Brönnimann, Jorg Franke, Christoph C RaibleAbstract:Seamless quantification of past and present climate variability is needed to understand the Earth’s climate well enough to make accurate predictions for the future. This study addresses whether Tree-Ring-dominated proxy data properly represent the frequency spectrum of true climate variability. The results challenge the validity of detection and attribution investigations based on these data.
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orbital forcing of Tree Ring data
Nature Climate Change, 2012Co-Authors: Jan Esper, Mauri Timonen, Steffen Holzkamper, David Frank, Eduardo Zorita, Jürg Luterbacher, Sebastian Wagner, Nils Fischer, Rob Wilson, Daniel NievergeltAbstract:Based on an analysis of maximum latewood density data from northern Scandinavia, along with published dendrochronological records, this study finds evidence that previous Tree-Ring-reliant reconstructions of large-scale near-surface air temperature underestimated long-term pre-industrial warmth duRing Medieval and Roman times.
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orbital forcing of Tree Ring data
Nature Climate Change, 2012Co-Authors: Jan Esper, Mauri Timonen, Steffen Holzkamper, David Frank, Eduardo Zorita, Jürg Luterbacher, Sebastian Wagner, Nils Fischer, Rob Wilson, Daniel NievergeltAbstract:Based on an analysis of maximum latewood density data from northern Scandinavia, along with published dendrochronological records, this study finds evidence that previous Tree-Ring-reliant reconstructions of large-scale near-surface air temperature underestimated long-term pre-industrial warmth duRing Medieval and Roman times. Solar insolation changes, resulting from long-term oscillations of orbital configurations1, are an important driver of Holocene climate2,3. The forcing is substantial over the past 2,000 years, up to four times as large as the 1.6 W m−2 net anthropogenic forcing since 1750 (ref. 4), but the trend varies considerably over time, space and with season5. Using numerous high-latitude proxy records, slow orbital changes have recently been shown6 to gradually force boreal summer temperature cooling over the common era. Here, we present new evidence based on maximum latewood density data from northern Scandinavia, indicating that this cooling trend was stronger (−0.31 °C per 1,000 years, ±0.03 °C) than previously reported, and demonstrate that this signature is missing in published Tree-Ring proxy records. The long-term trend now revealed in maximum latewood density data is in line with coupled general circulation models7,8 indicating albedo-driven feedback mechanisms and substantial summer cooling over the past two millennia in northern boreal and Arctic latitudes. These findings, together with the missing orbital signature in published dendrochronological records, suggest that large-scale near-surface air-temperature reconstructions9,10,11,12,13 relying on Tree-Ring data may underestimate pre-instrumental temperatures including warmth duRing Medieval and Roman times.
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Divergence pitfalls in Tree-Ring research
Climatic Change, 2009Co-Authors: Jan Esper, David FrankAbstract:,andinto degrees Celsius—forming the cornerstone for proxy reconstructions (Cookand Kairiukstis 1990). The specific subject of the Loehle (2009) contribution is onnon-linear calibration techniques, which have been considered when proxy data in-dicate inconsistent responses to medium and extreme temperature deviations. Non-linear calibration has a long-standing history in Tree-Ring research (see Fritts 1976 foran introduction), and variants of non-linear response models have been applied in avariety of Tree-Ring analyses over the past decades (e.g., Carrer and Urbinati 2001;Fritts 1969; Graumlich and Brubaker 1986; Woodhouse 1999). So, while approachesto tackle non-linear Tree-Ring/climate associations are relevant when dealing withproxy data, it is, however, the motivation that called for re-attention to thesetechniques that is of particular interest: the divergence phenomenon (DP) in Tree-Ring research.DP was first described over a decade ago by Jacoby and D’Arrigo (1995)andsince then has been reported from a variety of sites mainly concentrated towardsthe Northern Hemisphere boreal forest zone (see D’Arrigo et al. 2008 for a review).DP effectively describes a disassociation of late twentieth century (typically post-1960) Tree growth parameters, such as Ring width or maximum latewood density,from regional temperature trends. This disassociation does not necessarily comprisea weakening of the high-frequency climate signal. That is, inter-annual Tree-Ringvariation may be predominantly controlled by temperatures, but the long-term
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Testing for Tree-Ring divergence in the European Alps
Global Change Biology, 2008Co-Authors: Ulf Büntgen, David Frank, Rob Wilson, Marco Carrer, Carlo Urbinati, Jan EsperAbstract:Evidence for reduced sensitivity of Tree growth to temperature has been reported from multiple forests along the high northern latitudes. This alleged circumpolar phenomenon described the apparent inability of temperature-sensitive Tree-Ring width and density chronologies to parallel increasing instrumental temperature measurements since the mid-20th century. In addition to such low-frequency trend offset, the inability of formerly temperature-sensitive Tree growth to reflect high-frequency temperature signals in a warming world is indicated at some boreal sites, mainly in Alaska, the Yukon and Siberia. Here, we refer to both of these findings as the ‘divergence problem’ (DP), with their causes and scale being debated. If DP is widespread and the result of climatic forcing, the overall reliability of Tree-Ring-based temperature reconstructions should be questioned. Testing for DP benefits from well-replicated Tree-Ring and instrumental data spanning from the 19th to the 21st century. Here, we present a network of 124 larch and spruce sites across the European Alpine arc. Tree-Ring width chronologies from 40 larch and 24 spruce sites were selected based on their correlation with early (1864‐1933) instrumental temperatures to assess their ability of tracking recent (1934‐2003) temperature variations. After the Tree-Ring series of both species were detrended in a manner that allows low-frequency variations to be preserved and scaled against summer temperatures, no unusual late 20th century DP is found. Independent Tree-Ring width and density evidence for unprecedented late 20th century temperatures with respect to the past millennium further reinforces our results.
