Reconstructing summer upper-level flow in the northern Rocky Mountains using an alpine larch tree-ring chronology

2020 ◽  
Vol 79 (3) ◽  
pp. 207-218
Author(s):  
EE Montpellier ◽  
PT Soulé ◽  
PA Knapp ◽  
L Baker Perry

Mid-latitude mesoscale weather during the climatological summer is strongly influenced by fluctuations in synoptic-scale circulation patterns. Previous research has linked Arctic amplification to alterations in summer synoptic climatology, leading to more extreme weather events in the mid-latitudes. In this study, seasonal (JJA) upper-level (500 hPa) atmospheric flow is reconstructed in the mid-latitudes using an alpine larch Larix lyallii Parl. tree-ring chronology sampled from western Montana. Significant relationships were found between alpine larch radial growth and upper-level flow patterns derived from the North American Regional Reanalysis dataset (1979-2015). Meridional and zonal flows that manifest in ridging are associated with enhanced radial growth of alpine larch (i.e. meridional flow west [r = 0.504, p = 0.001] and zonal flow north [r = 0.642, p < 0.001] of the study site). Meridional and zonal flows associated with troughing result in decreased radial growth (i.e. meridional flow east [r = -0.497, p = 0.001] and zonal flow south [r = -0.584, p < 0.001] of the study site). Using the leave-one-out method, a linear regression model was calibrated and verified between a principal component analysis score derived from measurements of upper-level flow in western North America and alpine larch tree growth. The 444 yr climate reconstruction of summer 500 hPa flow suggests that ridging is becoming more intense over the western United States and Canada since the 1980s.

2016 ◽  
Vol 23 (2) ◽  
pp. 14-19 ◽  
Author(s):  
U K Thapa ◽  
S K Shah ◽  
N P Gaire ◽  
D R Bhuju ◽  
A. Bhattacharyya ◽  
...  

 This study aims to understand the influence of climate on radial growth of Abies pindrow growing in the plateau of mixed forest in Khaptad National Park in Western Nepal Himalaya. Based on the dated tree-ring samples, 362-year long tree-ring width chronology was developed dating back to 1650. The studied taxa of this region was found to have dendroclimatic potentiality that was evident from the chronology statistics calculated. The tree-ring chronology was correlated with climate (temperature and precipitation) data to derive the tree-growth climate relationship. The result showed significant negative relationship with March-May temperature and positive relationship with March-May precipitation. This indicates that the availability of moisture is the primary factor in limiting the tree growth.Banko Janakari, Vol. 23, No. 2, 2013


2009 ◽  
Vol 34 (-1) ◽  
pp. 49-56 ◽  
Author(s):  
Daniel Patón ◽  
Ricardo García-Herrera ◽  
Javier Cuenca ◽  
Mamen Galavis ◽  
Fidel Roig

Influence of Climate on Radial Growth of Holm Oaks (Quercus Ilex Subsp. Ballota Desf) from SW SpainA total of 47 trunk sections from Holm Oak (Quercus ilex subsp. ballota Desf) trees growing at two different sites at the Extremadura region (SW Spain) were considered in the computation of a regional tree-ring chronology useful to interpret the tree-ring/Mediterranean climate relationships. This is the first dendroclimatological research of Holm Oaks conducted to reveal its potential use as a climatic proxy. The obtained tree-ring chronologies were compared with climatic parameters based on monthly, seasonal and annual rainfall, and monthly maximum, minimum and average temperature. The best correlations were obtained with maximum temperatures during the period between previous winter and early spring. Influence of rainfall was less relevant. Growth of this species indicates a typical bimodal (spring and autumn) strategy that avoids low winter temperatures and summer drought. Despite some technical difficulties recognizing tree rings in Holm Oaks, its good sensitivity to climate variability and its wide distribution and longevity (~800 years), allow us to consider this species as a good candidate for temperature reconstructions in the Mediterranean Basin.


2010 ◽  
Vol 36 (-1) ◽  
pp. 9-16 ◽  
Author(s):  
Michal Rybníček ◽  
Petr čermák ◽  
Tomáš Žid ◽  
Tomáš Kolář

Radial Growth and Health Condition of Norway Spruce (Picea Abies(L.) Karst.) Stands in Relation to Climate (Silesian Beskids, Czech Republic)The research was conducted in selected spruce stands of the Silesian Beskids aged over 70 at altitudes from 403 m a.s.l. to 794 m a.s.l. in 2008. The samples were taken and processed in compliance with standard dendrochronological methodology. Tree rings were measured and the tree-ring curves were synchronized using the PAST4 application. The age trend was removed in the ARSTAN application and the climatic influences were modelled in the DendroClim application. The regional standard tree-ring chronology shows an obvious decrease in the radial increment from the beginning of the 1970s to the mid-1990s. The gradual increase in radial increment which followed in the second half of the 1990s was interrupted in 2000, 2003, and 2006. Most of the years with the decreased radial increment have been confirmed by the analysis of significant negative years. The radial increment statistically significantly correlates with the precipitation in July and September of the previous year, precipitation in June of the year in question and precipitation during the vegetation period. Moreover, the growth of spruce is statistically significantly affected by temperatures in October of the previous year and March of the year in question. Additionally, the paper includes habitual monitoring of trees and the volume of salvage cutting in these districts. The condition of the habit of trees and the development of salvage cuttings agree with the hypothesis about strong stress load or its considerable increase in 2003 and the following years.


Radiocarbon ◽  
2019 ◽  
Vol 62 (4) ◽  
pp. 891-899 ◽  
Author(s):  
Adam Sookdeo ◽  
Bernd Kromer ◽  
Ulf Büntgen ◽  
Michael Friedrich ◽  
Ronny Friedrich ◽  
...  

ABSTRACTAdvances in accelerator mass spectrometry have resulted in an unprecedented amount of new high-precision radiocarbon (14C) -dates, some of which will redefine the international 14C calibration curves (IntCal and SHCal). Often these datasets are unaccompanied by detailed quality insurances in place at the laboratory, questioning whether the 14C structure is real, a result of a laboratory variation or measurement-scatter. A handful of intercomparison studies attempt to elucidate laboratory offsets but may fail to identify measurement-scatter and are often financially constrained. Here we introduce a protocol, called Quality Dating, implemented at ETH-Zürich to ensure reproducible and accurate high-precision 14C-dates. The protocol highlights the importance of the continuous measurements and evaluation of blanks, standards, references and replicates. This protocol is tested on an absolutely dated German Late Glacial tree-ring chronology, part of which is intercompared with the Curt Engelhorn-Center for Archaeometry, Mannheim, Germany (CEZA). The combined dataset contains 170 highly resolved, highly precise 14C-dates that supplement three decadal dates spanning 280 cal. years in IntCal, and provides detailed 14C structure for this interval.


2015 ◽  
Vol 42 (1) ◽  
Author(s):  
Magdalena Opała

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.


Author(s):  
Yanhua Zhang ◽  
Shengzuo Fang ◽  
Ye Tian ◽  
Linlin Wang ◽  
Yi Lv

AbstractPoplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.


2019 ◽  
Author(s):  
Andrew R. Slaughter ◽  
Saman Razavi

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).


2013 ◽  
Vol 22 (2) ◽  
pp. 36-42 ◽  
Author(s):  
D. K. Kharal ◽  
T. Fujiwara

Tree ring analysis is one of the most useful methods in volume and biomass estimation especially of the conifer trees. Ring width and ring density are important parameters in dendrochronological research. The present research was carried out with the aim of estimating the radial and volumetric growth of the Japanese Cypress trees (Chamaecyperis obstusa and C. pisifera). Destructive method was used while collecting the wood samples from the selected trees. Ring width and ring density were measured using soft X-ray densitometry method using micro-densitometer. Computer programme, developed by the Forestry and Forest Products Research Institute, Japan was used to analyze the ring with and ring density data. The average ring width of the Chamaecyparis spp. was found to be about 3.4 mm at the age of 30 years. However, two types of growth pattern were observed in the trees. Average radial growth was about 5% every year during the first 20 years of the tree age, whereas, the average radial growth was negative during the age of 20–30 years. Average density of the tree rings were increased by about 11% in each height of the trees starting from the ground. Similarly, the stem density decreased by about 3.4% annually along the radial direction from the pith.DOI: http://dx.doi.org/10.3126/banko.v22i2.9197Banko Janakari: A Journal of Forestry Information for NepalVol. 22, No. 2, 2012 November Page: 36-42 Uploaded date: 12/1/2013 


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