Timberline tree-ring statistics examined through chronology stripping

Abstract Tree-ring data is commonly used in forest science and dendrochronology. As the collected datasets represent restricted populations of theoretical infinite sample size, an interesting question deals with the sample selection that is carried out during the fieldwork and through the data analyses. This paper considers the latter issue, by statistically examining a recently completed Scots pine dataset of timberline tree-rings from Lapland (northern Finland). Following the detrending of individual ring-width series, the composition of the data was restricted using a pre-determined criteria of linear correlativity between the individual sample series and the master chronology (Rmaster). This procedure reduced both the number of sites and the sample size (i.e. the number of individual tree-ring series) and altered the tree-ring statistics of the remaining subset of the data in a systematic fashion. It was seen that the first-order autocorrelation, mean sensitivity and standard deviation all ascended with the uplifted Rmaster criterion. Conspicuously, such filtering also reduced the correlation between the resulting tree-ring chronology and climate parameter. The results indicated that the screening of the data will alter the chronology statistics in a way that may be artificially generated, irrelative to the predetermined sample selection criteria. We remain to assume that the most fundamental selection of data is attained through the cross-dating process.

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Short communication: Many missing rings in old Canary pines can be related with age, fires and traditional uses

Forest Systems ◽

10.5424/fs/2017262-10253 ◽

2017 ◽

Vol 26 (2) ◽

pp. eSC02 ◽

Cited By ~ 2

Author(s):

Mar Génova ◽

Carlos Santana ◽

Begoña Martínez

Keyword(s):

Tree Ring ◽

Short Communication ◽

Pinus Canariensis ◽

Tree Ring Chronology ◽

Individual Tree ◽

Gran Canaria ◽

Growth Changes ◽

Ring Analysis ◽

The Individual ◽

Old Trees

Aim and area of study: In the present paper we estimated the age of four monumental Pinus canariensis of Gran Canaria (Canary Islands, Spain) by means of tree-ring analysis. Many tree-ring series have been accurately studied and many missing rings have been determined.Material and methods: The trees were dead and the samples analysed were big disks. We measured numerous radii and crossdated the individual tree-ring series, paying particular attention to the existence and location of missing rings. We have distinguished between missing outer rings (MORs) and missing inner rings (MIRs) and analysed the possible causes of both.Main results: We determined an average of 8.8% total missing rings (MRs) for these long-lived trees, with a maximum of 96 MRs in a series of over 500. We have tried to establish a tree-ring chronology on Gran Canaria Island, also having the tree-ring series from Inagua site, but the long individual tree-ring series analysed do not crossdate between them. Research highlights: We consider the Canary pine a species hard to conducting dendroecological studies, especially if the samples come from managed old trees, in which a large amount of known and potentially unknown missing rings can hampered dating. Even knowing the difficulties involved in dendrochronological analyses of P. canariensis, we can confirm that it is a long-lived species, which can grow to over 500 years, and some of whose growth changes could be associated with certain historical and ecological events.

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Climatic aspect of fir (Abies sibirica Ledeb.) mortality in the Eastern Sayan Mountains

Proceedings of the VII International Scientific Conference, dedicated to the 135th anniversary of the P.N. Krylov Herbarium of Tomsk State University and the 170th anniversary of P.N. Krylov ◽

10.17223/978-5-94621-927-3-2020-29 ◽

2020 ◽

Author(s):

I.A. Petrov ◽

◽

A.S. Shushpanov ◽

S.T. Im ◽

A.S. Golyukov ◽

...

Keyword(s):

Tree Ring ◽

Ring Width ◽

Radial Increment ◽

Individual Tree ◽

Abies Sibirica ◽

The Past ◽

Polygraphus Proximus ◽

Vital State ◽

Eastern Sayan ◽

The Individual

The study considers the climatic response of fir (Abies sibirica Ledeb.) radial increment in the zones of dark coniferous decline on the northern spurs of the Eastern Sayan Mountains. Radial increment of 203 fir trees was analyzed. The measurement of the tree ring width and the development of tree-ring chronologies were carried out according to the generally recognized dendrochronological methods. The individual tree-ring chronologies obtained were divided into two groups according to the characteristics of the vital state of trees and radial increment trends over the past decades. It was found that significant differences in radial increment were observed after the drought in 1999. Comparison of the radial increment indices with the SPEI showed that the depression in radial increment coincide with a decrease in the level of atmospheric moisture and an increase in the sensitivity of trees to atmospheric droughts. Atmospheric drought, which caused a decrease in radial increment, also preceded an increase in fir mortality and an outbreak of Polygraphus proximus Blandford.

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Tree growth across the Nepal Himalaya during the last four centuries

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133317714247 ◽

2017 ◽

Vol 41 (4) ◽

pp. 478-495 ◽

Cited By ~ 15

Author(s):

UK Thapa ◽

S St. George ◽

DK Kharal ◽

NP Gaire

Keyword(s):

Tree Ring ◽

Tree Growth ◽

Environmental Changes ◽

Ring Width ◽

High Elevation ◽

Forest Growth ◽

Tree Ring Width ◽

Early 19Th Century ◽

Tree Ring Data ◽

Instrumental Records

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.

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Developing a triple tree-ring constraint for tree growth and physiology in a global land surface model

10.5194/egusphere-egu21-13546 ◽

2021 ◽

Author(s):

Jonathan Barichivich ◽

Philippe Peylin ◽

Valérie Daux ◽

Camille Risi ◽

Jina Jeong ◽

...

Keyword(s):

Tree Ring ◽

Land Surface ◽

Forest Ecosystems ◽

Ring Width ◽

Land Surface Model ◽

Surface Model ◽

Growth Variability ◽

Tree Ring Data ◽

Surface Models ◽

Global Land

Gradual anthropogenic warming and parallel changes in the major global biogeochemical cycles are slowly pushing forest ecosystems into novel growing conditions, with uncertain consequences for ecosystem dynamics and climate. Short-term forest responses (i.e., years to a decade) to global change factors are relatively well understood and skilfully simulated by land surface models (LSMs). However, confidence on model projections weaken towards longer time scales and to the future, mainly because the long-term responses (i.e., decade to century) of these models remain unconstrained. This issue limits confidence on climate model projections. Annually-resolved tree-ring records, extending back to pre-industrial conditions, have the potential to constrain model responses at interannual to centennial time scales. Here, we constrain the representation of tree growth and physiology in the ORCHIDEE global land surface model using the simulated interannual variability of tree-ring width and carbon (&#916;13C) and oxygen (&#948;18O) stable isotopes in six sites in boreal and temperate Europe.&#160; The model simulates &#916;13C (r = 0.31-0.80) and &#948;18O (r = 0.36-0.74) variability better than tree-ring width variability (r < 0.55), with an overall skill similar to that of other state-of-the-art models such as MAIDENiso and LPX-Bern. These results show that growth variability is not well represented, and that the parameterization of leaf-level physiological responses to drought stress in the temperate region can be improved with tree-ring data. The representation of carbon storage and remobilization dynamics is critical to improve the realism of simulated growth variability, temporal carrying over and recovery of forest ecosystems after climate extremes. The simulated physiological response to rising CO2 over the 20th century is consistent with tree-ring data in the temperate region, despite an overestimation of seasonal drought stress and stomatal control on photosynthesis. Photosynthesis correlates directly with isotopic variability, but correlations with &#948;18O combine physiological effects and climate variability impacts on source water signatures. The integration of tree-ring data (i.e. the triple constraint: width, &#916;13C and &#948;18O) and land surface models as demonstrated here should contribute towards reducing current uncertainties in forest carbon and water cycling.

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Forward modelling of tree-ring width and comparison with a global network of tree-ring chronologies

Climate of the Past ◽

10.5194/cp-10-437-2014 ◽

2014 ◽

Vol 10 (2) ◽

pp. 437-449 ◽

Cited By ~ 49

Author(s):

P. Breitenmoser ◽

S. Brönnimann ◽

D. Frank

Keyword(s):

Data Assimilation ◽

Tree Ring ◽

Ring Width ◽

Global Network ◽

Threshold Temperature ◽

Tree Ring Width ◽

Data Set ◽

Observation Operator ◽

Tree Ring Data ◽

Wide Range

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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Bristlecone pine tree rings and volcanic eruptions over the last 5000 yr

Quaternary Research ◽

10.1016/j.yqres.2006.07.004 ◽

2007 ◽

Vol 67 (1) ◽

pp. 57-68 ◽

Cited By ~ 116

Author(s):

Matthew W. Salzer ◽

Malcolm K. Hughes

Keyword(s):

Tree Ring ◽

Ice Core ◽

Ring Width ◽

Volcanic Eruptions ◽

Pine Tree ◽

Tree Ring Data ◽

Pinus Longaeva ◽

Bristlecone Pine ◽

Ice Core Record ◽

Pinus Aristata

AbstractMany years of low growth identified in a western USA regional chronology of upper forest border bristlecone pine (Pinus longaeva and Pinus aristata) over the last 5000 yr coincide with known large explosive volcanic eruptions and/or ice core signals of past eruptions. Over the last millennium the agreement between the tree-ring data and volcano/ice-core data is high: years of ring-width minima can be matched with known volcanic eruptions or ice-core volcanic signals in 86% of cases. In previous millennia, while there is substantial concurrence, the agreement decreases with increasing antiquity. Many of the bristlecone pine ring-width minima occurred at the same time as ring-width minima in high latitude trees from northwestern Siberia and/or northern Finland over the past 4000–5000 yr, suggesting climatically-effective events of at least hemispheric scale. In contrast with the ice-core records, the agreement between widely separated tree-ring records does not decrease with increasing antiquity. These data suggest specific intervals when the climate system was or was not particularly sensitive enough to volcanic forcing to affect the trees, and they augment the ice core record in a number of ways: by providing confirmation from an alternative proxy record for volcanic signals, by suggesting alternative dates for eruptions, and by adding to the list of years when volcanic events of global significance were likely, including the mid-2nd-millennium BC eruption of Thera.

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The 443-Year Tree-Ring Chronology for the Scots Pine from Upper Silesia (Poland) as A Dating Tool and Climate Proxy

Geochronometria ◽

10.1515/geochr-2015-0005 ◽

2015 ◽

Vol 42 (1) ◽

Cited By ~ 5

Author(s):

Magdalena Opała

Keyword(s):

Tree Ring ◽

Scots Pine ◽

Meteorological Data ◽

Ring Width ◽

Tree Ring Chronology ◽

Series Length ◽

Upper Silesia ◽

Living Tree ◽

Absolute Dating ◽

The Mean

Abstract An annually resolved and absolutely dated ring-width chronology spanning 443 years has been constructed using the historical and living-tree Scots pine samples from the Upper Silesia, south of Poland. The constructed regional chronology, based on six object chronologies, covers the period of 1568-2010. It is composed of 178 wood samples with the mean correlation of 0.51, mean series length of 104 years and mean EPS of 0.85. In total, 65 extreme years were distinguished. Their inde-pendent verification, based on the historical and meteorological data, showed significant correlation with the exceptionally cold/mild winters as well as severe droughts. The comparison of the extreme years with the other Polish pine chronologies showed similarities in the years with the anomalous winter conditions. Some extreme years can be associated with the exceptional pluvial conditions; these years are common in the Central European hydroclimatic tree-ring records. The construction of this regional pine chronology enables for the absolute dating of many architectural monuments from investigated region. The application of the new chronology for the dating of local wood can support interpretations of changes in the environment of the Upper Silesian region. In the future it can also be used as the basis for climate reconstruction.

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Paleo-hydrologic reconstruction of 400 years of past flows at a weekly time step for major rivers of Western Canada

10.5194/essd-2019-57 ◽

2019 ◽

Author(s):

Andrew R. Slaughter ◽

Saman Razavi

Keyword(s):

Time Series ◽

Water Resources ◽

Tree Ring ◽

Flow Distribution ◽

Future Climate Change ◽

Western Canada ◽

Tree Ring Chronology ◽

Time Step ◽

Water Resources Systems ◽

Tree Ring Data

Abstract. The assumption of stationarity in water resources no longer holds, particularly within the context of future climate change. Plausible scenarios of flows that fluctuate outside the envelope of variability of the gauging data are required to assess the robustness of water resources systems to future conditions. This study presents a novel method of generating weekly-time-step flows based on tree-ring chronology data. Specifically, this method addresses two long-standing challenges with paleo-reconstruction: (1) the typically limited predictive power of tree-ring data at the annual and sub-annual scale, and (2) the inflated short-term persistence in tree-ring time series and improper use of prewhitening. Unlike the conventional approach, this method establishes relationships between tree-ring chronologies and naturalised flow at a biennial scale to preserve persistence properties and variability of hydrological time series. Biennial flow reconstructions are further disaggregated to weekly, according to the weekly flow distribution of reference two-year instrumental periods, identified as periods with broadly similar tree-ring properties to that of every two-year paleo-period. The Saskatchewan River Basin (SaskRB), a major river in Western Canada, is selected as a study area, and weekly flows in its four major tributaries are extended back to the year 1600. The study shows that the reconstructed flows properly preserve the statistical properties of the reference flows, particularly, short- to long-term persistence and the structure of variability across time scales. An ensemble approach is presented to represent the uncertainty inherent in the statistical relationships and disaggregation method. The ensemble of reconstructed weekly flows are publically available for download from https://doi.org/10.20383/101.0139 (Slaughter and Razavi, 2019).

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Entwicklung klimasensitiver Wachstumsfunktionen für das Szenariomodell «Massimo»

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2015.0389 ◽

2015 ◽

Vol 166 (6) ◽

pp. 389-398 ◽

Cited By ~ 3

Author(s):

Brigitte Rohner ◽

Esther Thürig

Keyword(s):

Tree Ring ◽

Tree Growth ◽

Tree Species ◽

Climatic Factors ◽

Climate Variables ◽

Individual Tree ◽

Climate Effects ◽

Growth Functions ◽

Tree Ring Data ◽

Scenario Model

Development of climate-dependent growth functions for the scenario model “Massimo” Tree growth is substantially influenced by climatic factors. In the face of climate change, climate effects should therefore be included in estimations of Switzerland's future forest productivity. In order to include climate effects in the growth functions of the “Massimo” model, which is typically applied to project forest resources in Switzerland, we statistically modelled climate effects on tree growth representatively for Switzerland by simultaneously considering further growth-influencing factors. First, we used tree ring data to evaluate how climate variables should be defined. This analyses showed that for modelling multi-year tree growth we should use averages of whole-year variables. Second, we fitted nonlinear mixed-effects models separately for the main tree species to individual-tree growth data from the Swiss National Forest Inventory. In these models, we combined climate variables defined according to the results of the tree ring study with various further variables that characterize sites, stands and individual trees. The quantified effects were generally plausible and explained convincingly the physiological differences between the species. The statistical growth models for the main tree species will now be included in the forest scenario model “Massimo”. This will allow for founded analyses of scenarios which assume changing climatic conditions.

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An 854-Year Tree-Ring Chronology of Scots Pine for South-West Finland

Studia Quaternaria ◽

10.2478/squa-2014-0006 ◽

2014 ◽

Vol 31 (1) ◽

pp. 61-68 ◽

Cited By ~ 4

Author(s):

Samuli Helama ◽

Jari Holopainen ◽

Mauri Timonen ◽

Kari Mielikäinen

Keyword(s):

Tree Ring ◽

Ring Width ◽

Summer Precipitation ◽

Total Sample ◽

Early Summer ◽

The South ◽

Tree Ring Chronology ◽

The North ◽

South West ◽

The North Atlantic Oscillation

Abstract A near-millennial tree-ring chronology (AD 1147-2000) is presented for south-west Finland and analyzed using dendroclimatic methods. This is a composite chronology comprising samples both from standing pine trees (Pinus sylvestris L.) and subfossil trunks as recovered from the lake sediments, with a total sample size of 189 tree-ring sample series. The series were dendrochronologically cross-dated to exact calendar years to portray variability in tree-ring widths on inter-annual and longer scales. Al though the studied chronology correlates statistically significantly with other long tree-ring width chronologies from Finland over their common period (AD 1520-1993), the south-west chronology did not exhibit similarly strong mid-summer temperature or spring/early-summer precipitation signals in comparison to published chronologies. On the other hand, the south-west chronology showed highest correlations to the North Atlantic Oscillation indices in winter/spring months, this association following a dendroclimatic feature common to pine chronologies over the region and adjacent areas. Paleoclimatic comparison showed that tree-rings had varied similarly to central European spring temperatures. It is postulated that the collected and dated tree-ring material could be studied for wood surface reflectance (blue channel light intensity) and stable isotopes, which both have recently shown to correlate notably well with summer temperatures.

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