The dendrochronological characteristics of alpine Larch

1995 ◽  
Vol 25 (5) ◽  
pp. 777-789 ◽  
Author(s):  
M.E. Colenutt ◽  
B.H. Luckman
Keyword(s):  
Ring Width ◽  
Principal Component ◽  
Geographic Area ◽  
Tree Line ◽  
Common Variance ◽  
Continental Divide ◽  
Tree Ring Data ◽  
Components Analysis ◽  
Cross Dating ◽  
Alpine Larch

Ring-width chronologies have been developed for alpine larch (Larixlyallii Pari.) at six tree-line sites in the Banff–Kananaskis area of the southern Canadian Rockies. Evaluation of all chronologies confirms that alpine larch ring-width series have higher mean sensitivities, lower autocorrelation, and greater common variance than series from other tree species growing at tree line in this area. Missing and very narrow rings created cross-dating difficulties at all sites but were most problematic for the sites along the Continental Divide. Up to 1% of the rings were missing from entire chronologies, but for specific years, up to 77% of the rings were missing at one site. Marker (narrow) rings were present at all sites for the years 1610, 1654, 1715, 1720, 1723, 1752, 1799, 1824, 1842, 1844, 1915, 1925, 1951, and 1971. Tree growth rates were reduced for the periods 1675–1710, 1815–1850, and 1960–1978 whereas increased growth occurred during 1650–1680, 1750–1800, 1850–1900, and 1920–1950. The only factor that could affect all sites over such a broad geographic area is climate. Principal components analysis indicated that the first eigenvector derived from the six chronologies accounted for 70.7% of their common variance and the first three components accounted for 91.6%. The high correlation between the six first principal component and standard chronologies suggested that either method may be used for standardizing tree-ring data from alpine larch.

scholarly journals Timberline tree-ring statistics examined through chronology stripping

2012 ◽  
Vol 56 (1) ◽  
pp. 5-15
Author(s):  
Mauri Timonen ◽  
Kari Mielikäinen ◽  
Samuli Helama
Keyword(s):  
Sample Size ◽  
Tree Ring ◽  
Sample Selection ◽  
Ring Width ◽  
Tree Ring Chronology ◽  
Individual Tree ◽  
Tree Ring Data ◽  
The Individual ◽  
Climate Parameter ◽  
Cross Dating

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.

scholarly journals Latewood Ring Width Reveals CE 1734 Felling Dates for Walker House Timbers in Tupelo, Mississippi, USA

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 670
Author(s):  
Thomas W. Patterson ◽  
Grant L. Harley ◽  
David H. Holt ◽  
Raymond T. Doherty ◽  
Daniel J. King ◽  
...  
Keyword(s):  
Construction Materials ◽  
Ring Width ◽  
Pinus Palustris ◽  
The United States ◽  
Quercus Alba ◽  
Gulf Coastal Plain ◽  
White Oak ◽  
Southeastern Us ◽  
Tree Ring Data ◽  
Cross Dating

Dendroarchaeology is under-represented in the Gulf Coastal Plain region of the United States (US), and at present, only three published studies have precision dated a collection of 18th–19th-century structures. In this study, we examined the tree-ring data from pine, poplar, and oak timbers used in the Walker House in Tupelo, Mississippi. The Walker House was constructed ca. the mid-1800s with timbers that appeared to be recycled from previous structures. In total, we examined 30 samples (16 pines, 8 oaks, and 6 poplars) from the attic and crawlspace. We cross-dated latewood ring growth from the attic pine samples to the period 1541–1734 (r = 0.52, t = 8.43, p < 0.0001) using a 514-year longleaf pine (Pinus palustris Mill.) latewood reference chronology from southern Mississippi. The crawlspace oak samples produced a 57-year chronology that we dated against a white oak (Quercus alba L.) reference chronology from northeast Alabama to the period 1765–1822 (r = 0.36, t = 2.83, p < 0.01). We were unable to cross-date the six poplar samples due to a lack of poplar reference chronologies in the region. Our findings have two important implications: (1) the pine material dated to 1734 represents the oldest dendroarchaeology-confirmed dating match for construction materials in the southeastern US, and (2) cross-dating latewood growth for southeastern US pine species produced statistically significant results, whereas total ring width failed to produce significant dating results.

Dendrochronological investigation of Larixlyallii at Larch Valley, Alberta

1991 ◽  
Vol 21 (8) ◽  
pp. 1222-1233 ◽  
Author(s):  
M. E. Colenutt ◽  
B. H. Luckman
Keyword(s):  
Ring Width ◽  
Growth Conditions ◽  
Similar Response ◽  
Tree Line ◽  
Climate Data ◽  
Maximum Latewood Density ◽  
Engelmann Spruce ◽  
Latewood Density ◽  
Growing Conditions ◽  
Alpine Larch

Tree-ring chronologies have been developed for alpine larch (Larixlyallii Parl.), alpine fir (Abieslasiocarpa (Hook.) Nutt.), and Engelmann spruce (Piceaengelmannii Parry) for a tree-line site at Larch Valley in Banff National Park. The alpine larch and alpine fir chronologies are the first published chronologies developed for these species in the Canadian Cordillera. Alpine larch, a deciduous conifer, has many very narrow and missing rings, making chronology development difficult. These problems were resolved by identifying common marker rings among species growing at the same site. Chronologies for all three species show suppressed growth in the early to mid 1800s followed by a period of higher growth that peaked in the early to mid 20th century and has since declined. The exact timing and nature of response to favourable and unfavourable growth conditions vary with species. Alpine larch exhibits the highest sensitivity, lowest first-order autocorrelation, and greatest common variance, suggesting it has excellent potential as a source of proxy climate data for tree-line sites in this area. Preliminary correlations between Lake Louise climate data and larch ring-width and maximum latewood density chronologies show that there are significant correlations with summer temperature variables. Engelmann spruce and alpine fir growing at the same site show a similar response but are more strongly influenced by precipitation and growing conditions of the previous year.

scholarly journals EXPRESS: Exploration of Principal Component Analysis: Deriving PCA Visually Using Spectra

2021 ◽  
pp. 000370282098784
Author(s):  
James Renwick Beattie ◽  
Francis Esmonde-White
Keyword(s):  
Principal Components ◽  
Principal Component ◽  
Original Data ◽  
Specific Chemical ◽  
Successive Refinement ◽  
Minimal Loss ◽  
Components Analysis ◽  
The Mathematical Model ◽  
Application Specific ◽  
Reconstructed Data

Spectroscopy rapidly captures a large amount of data that is not directly interpretable. Principal Components Analysis (PCA) is widely used to simplify complex spectral datasets into comprehensible information by identifying recurring patterns in the data with minimal loss of information. The linear algebra underpinning PCA is not well understood by many applied analytical scientists and spectroscopists who use PCA. The meaning of features identified through PCA are often unclear. This manuscript traces the journey of the spectra themselves through the operations behind PCA, with each step illustrated by simulated spectra. PCA relies solely on the information within the spectra, consequently the mathematical model is dependent on the nature of the data itself. The direct links between model and spectra allow concrete spectroscopic explanation of PCA, such the scores representing ‘concentration’ or ‘weights’. The principal components (loadings) are by definition hidden, repeated and uncorrelated spectral shapes that linearly combine to generate the observed spectra. They can be visualized as subtraction spectra between extreme differences within the dataset. Each PC is shown to be a successive refinement of the estimated spectra, improving the fit between PC reconstructed data and the original data. Understanding the data-led development of a PCA model shows how to interpret application specific chemical meaning of the PCA loadings and how to analyze scores. A critical benefit of PCA is its simplicity and the succinctness of its description of a dataset, making it powerful and flexible.

Tree growth across the Nepal Himalaya during the last four centuries

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
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.

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

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

&lt;p&gt;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 (&amp;#916;&lt;sup&gt;13&lt;/sup&gt;C) and oxygen (&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O) stable isotopes in six sites in boreal and temperate Europe.&amp;#160; The model simulates &amp;#916;&lt;sup&gt;13&lt;/sup&gt;C (r = 0.31-0.80) and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O (r = 0.36-0.74) variability better than tree-ring width variability (r &lt; 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 &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O combine physiological effects and climate variability impacts on source water signatures. The integration of tree-ring data (i.e. the triple constraint: width, &amp;#916;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O) and land surface models as demonstrated here should contribute towards reducing current uncertainties in forest carbon and water cycling.&lt;/p&gt;

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

2014 ◽  
Vol 10 (2) ◽  
pp. 437-449 ◽  
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.

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

2007 ◽  
Vol 67 (1) ◽  
pp. 57-68 ◽  
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.

scholarly journals Prediction of Holocene Mercury Accumulation Trends by Combining Palynological and Geochemical Records of Lake Sediments (Black Forest, Germany)

2018 ◽  
Author(s):  
Martin Schütze ◽  
Gegeensuvd Tserendorj ◽  
Marta Pérez-Rodríguez ◽  
Manfred Rösch ◽  
Harald Biester
Keyword(s):  
Principal Component Regression ◽  
Principal Component ◽  
Terrestrial Ecosystems ◽  
Forest Vegetation ◽  
Warm Climate ◽  
Black Forest ◽  
Components Analysis ◽  
Lake Systems ◽  
Hg Accumulation

Forest vegetation plays a key role in the cycling of mercury (Hg) and organic matter (OM) in terrestrial ecosystems. Litterfall has been indicated as the major transport vector of atmospheric Hg to forest soils, which is eventually transported and stored in the sediments of forest lakes. Hence, it is important to understand how changes in forest vegetation affect Hg in soil and its biogeochemical cycling in lake systems. We investigated the pollen records and the geochemical compositions of sediments from two lakes (Schurmsee and Glaswaldsee) in the Black Forest (Germany) to evaluate whether long-term shifts in forest vegetation induced by climate or land use influenced Hg accumulation in the lakes. We were particularly interested to determine whether coniferous forests were associated with a larger export of Hg to aquatic systems than deciduous forests. Principal components analysis followed by principal component regression enabled us to describe the evolution of the weight of the latent processes determining the accumulation of Hg over time. Our results emphasize that the in-lake uptake of Hg during warm climate periods, soil erosion after deforestation and emissions from mining and other human activities triggered changes in Hg accumulation during the Holocene stronger than the changes caused by forest vegetation alone.

scholarly journals Zuwachs und Klimasensitivität von Baumarten im Ökogramm der kollinen und submontanen Stufe

2015 ◽  
Vol 166 (6) ◽  
pp. 380-388 ◽  
Author(s):  
Pascale Weber ◽  
Caroline Heiri ◽  
Mathieu Lévesque ◽  
Tanja Sanders ◽  
Volodymyr Trotsiuk ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Properties ◽  
Climate Sensitivity ◽  
Tree Species ◽  
Ring Width ◽  
Basal Area ◽  
Growth Potential ◽  
Basal Area Increment ◽  
Tree Ring Data ◽  
Mean Sensitivity

Growth potential and climate sensitivity of tree species in the ecogram for the colline and submontane zone In forestry practice a large amount of empirical knowledge exists about the productivity of individual tree species in relation to site properties. However, so far, only few scientific studies have investigated the influence of soil properties on the growth potential of various tree species along gradients of soil water as well as nutrient availability. Thus, there is a research gap to estimate the productivity and climate sensitivity of tree species under climate change, especially regarding productive sites and forest ad-mixtures in the lower elevations. Using what we call a «growth ecogram», we demonstrate species- and site-specific patterns of mean annual basal area increment and mean sensitivity of ring width (strength of year-to-year variation) for Fagus sylvatica, Quercus spp., Fraxinus excelsior, Picea abies, Abies alba and Pinus sylvestris, based on tree-ring data from 508 (co-)dominant trees on 27 locations. For beech, annual basal area increment ( average 1957–2006) was significantly correlated with tree height of the dominant sampling trees and proved itself as a possible alternative for assessing site quality. The fact that dominant trees of the different tree species showed partly similar growth potential within the same ecotype indicates comparable growth limitation by site conditions. Mean sensitivity of ring width – a measure of climate sensitivity – had decreased for oak and ash, while it had increased in pine. Beech showed diverging reactions with increasing sensitivity at productive sites (as measured by the C:N ratio of the topsoil), suggesting an increasing limitation by climate at these sites. Hence, we derive an important role of soil properties in the response of forests to climate change at lower elevations, which should be taken into account when estimating future forest productivity.

Sign in / Sign up

Export Citation Format

Share Document