Climate Variations in Northern North America (6000 Bp to Present) Reconstructed from Pollen and Tree-Ring Data

1989 ◽  
Vol 21 (1) ◽  
pp. 45 ◽  
Author(s):  
Henry F. Diaz ◽  
John T. Andrews ◽  
Susan K. Short
Keyword(s):  
North America ◽  
Tree Ring ◽  
Climate Variations ◽  
Tree Ring Data

scholarly journals Tree-ring data document 16th century megadrought over North America

Eos ◽  
2000 ◽  
Vol 81 (12) ◽  
pp. 121 ◽  
Author(s):  
David W. Stahle ◽  
Edward R. Cook ◽  
Malcolm K. Cleaveland ◽  
Matthew D. Therrell ◽  
David M. Meko ◽  
...  
Keyword(s):  
North America ◽  
Tree Ring ◽  
16Th Century ◽  
Tree Ring Data

Comparison between Blue Intensity (BI) and Maximum Latewood Density (MXD) tree-ring chronologies from the North American Boreal forests

2020 ◽  
Author(s):  
Laia Andreu-Hayles ◽  
Rosanne D'Arrigo ◽  
Rose Oelkers ◽  
Kevin Anchukaitis ◽  
Greg Wiles ◽  
...  
Keyword(s):  
High Resolution ◽  
North America ◽  
Tree Ring ◽  
Boreal Forests ◽  
Ring Width ◽  
Maximum Latewood Density ◽  
Latewood Density ◽  
Tree Ring Data ◽  
Summer Temperatures ◽  
Blue Intensity

<p>Tree ring-width (TRW) and Maximum Latewood Density (MXD) series have been largely used to develop high-resolution temperature reconstructions for the Northern Hemisphere. The divergence phenomenon, a weakening of the positive relationship between TRW and summer temperatures, has been observed particularly in northwestern North America chronologies. In contrast, MXD datasets have shown a more stable relationship with summer temperatures, but it is costly and labor-intensive to produce. Recently, methodological advances in image analyses have led to development of a less expensive and labor-intensive MXD proxy known as Blue Intensity (BI). Here, we compare 6 newly developed BI tree-ring chronologies of white spruce (<em>Picea glauca</em> [Moench] Voss) from high-latitude boreal forests in North America (Alaska in USA; Yukon and the Northwestern Territory in Canada), with MXD chronologies developed at the same sites. We assessed the quality of BI in relation to MXD based on mean correlation between trees, chronology reliability based on the Expressed Population Signal (EPS), spectral properties, and the strength and spatial extent of the temperature signal. Individual BI chronologies established significant correlations with summer temperatures showing a similar strength and spatial cover than MXD chronologies. Overall, the BI tree-ring data is emerging as a valuable proxy for generating high-resolution temperature spatial reconstructions over northwestern America.</p>

scholarly journals Using Tree Rings to Predict the Response of Tree Growth to Climate Change in the Continental United States during the Twenty-First Century

2010 ◽  
Vol 14 (19) ◽  
pp. 1-20 ◽  
Author(s):  
A. Park Williams ◽  
Joel Michaelsen ◽  
Steven W. Leavitt ◽  
Christopher J. Still
Keyword(s):  
Climate Change ◽  
United States ◽  
Tree Ring ◽  
Tree Growth ◽  
Ring Width ◽  
First Century ◽  
Annual Growth ◽  
Climate Variations ◽  
Tree Ring Data ◽  
Twenty First Century

Abstract In the early 1900s, tree-ring scientists began analyzing the relative widths of annual growth rings preserved in the cross sections of trees to infer past climate variations. Now, many ring-width index (RWI) chronologies, each representing a specific site and species, are archived online within the International Tree-Ring Data Bank (ITRDB). Comparing annual tree-ring-width data from 1097 sites in the continental United States to climate data, the authors quantitatively evaluated how trees at each site have historically responded to interannual climate variations. For each site, they developed a climate-driven statistical growth equation that uses regional climate variables to model RWI values. The authors applied these growth models to predict how tree growth will respond to twenty-first-century climate change, considering four climate projections. Although caution should be taken when extrapolating past relationships with climate into the future, the authors observed several clear and interesting patterns in the growth projections that seem likely if warming continues. Most notably, the models project that productivity of dominant tree species in the southwestern United States will decrease substantially during this century, especially in warmer and drier areas. In the northwest, nonlinear growth relationships with temperature may lead to warming-induced declines in growth for many trees that historically responded positively to warmer temperatures. This work takes advantage of the unmatched temporal length and spatial breath of annual growth data available within the ITRDB and exemplifies the potential of this ever-growing archive of tree-ring data to serve in meta-analyses of large-scale forest ecology.

scholarly journals The 600-mm precipitation isoline distinguishes tree-ring-width responses to climate in China

2018 ◽  
Vol 6 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Yu Liu ◽  
Huiming Song ◽  
Changfeng Sun ◽  
Yi Song ◽  
Qiufang Cai ◽  
...  
Keyword(s):  
Tree Ring ◽  
Large Scale ◽  
Ring Width ◽  
Severity Index ◽  
Annual Precipitation ◽  
Drought Severity ◽  
Climate Variations ◽  
Tree Ring Width ◽  
Past Climate ◽  
Tree Ring Data

AbstractThe numerous temperature and precipitation reconstructions in China based on tree-ring-width data have played significant roles in furthering the understanding of past climate changes. However, the geographical variability in the responses of trees to climate variations in China remains largely undetermined. Here, we describe an important spatial boundary in the response of trees to climate variations, namely the 600-mm annual precipitation isoline. We found that, to the north of this line, tree-ring widths are usually positively correlated with precipitation and negatively correlated with growing-season temperature. To the south of this line, the tree-ring widths respond positively to temperature, and winter half-year temperatures are the main reconstructed parameters, especially on the third topographical step of China. We also found that precipitation reconstructions based on tree-ring data and the Palmer Drought Severity Index almost exclusively fall in the region of the 200- to 600-mm annual precipitation isolines, not other regions. Our findings indicate that, when using multiple tree-ring-width chronologies for large-scale past climate reconstructions, the climatic signal of each tree-ring-width series should be carefully considered.

Insect defoliators as major disturbance factors in the high-altitude balsam fir forest of Mount Mégantic, southern Quebec

1998 ◽  
Vol 28 (12) ◽  
pp. 1832-1842 ◽  
Author(s):  
Louise Filion ◽  
Serge Payette ◽  
Ann Delwaide ◽  
Najat Bhiry
Keyword(s):  
North America ◽  
High Altitude ◽  
Tree Ring ◽  
Radial Growth ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Cumulative Impact ◽  
Tree Ring Data ◽  
Paper Birch

Tree-ring data from a mature balsam fir forest, located at the top of Mount Mégantic (elevation 1100 m), southern Quebec, suggest that insect defoliators were major disturbance factors in the development of high-altitude balsam fir forests. A comparison between the radial growth trend of balsam fir (Abies balsamea (L.) Mill.), a host species of the spruce budworm (Choristoneura fumiferana Clem.), and paper birch (Betula papyrifera Marsh), a nonhost species, showed that several growth depressions in the balsam fir chronology corrresponded to documented spruce budworm outbreaks in southern Quebec in the 1910s, 1950s, 1970s, and possibly in the 1870s. Tree mortality was extensive during the last infestation because of the relatively old age (>60 years) of many balsam fir and, possibly, to the cumulative impact of defoliation. The tree-ring series from paper birch showed several drops in radial growth after the 1930s, possibly related to the large-scale birch dieback that occurred in eastern North America. Macrofossil data (insect remains) from one sample of the uppermost organic soil layers (F horizon) confirm the presence of the spruce budworm at the study site. The ecological role of insect defoliators is discussed in the context of the high-altitude balsam fir forests in northeastern North America where abiotic disturbances are considered the primary controlling factors in stand dynamics.

Regional curve standardization: State of the art

The Holocene ◽  
2016 ◽  
Vol 27 (1) ◽  
pp. 172-177 ◽  
Author(s):  
Samuli Helama ◽  
Thomas M Melvin ◽  
Keith R Briffa
Keyword(s):  
Climate Variability ◽  
Tree Ring ◽  
Low Frequency ◽  
Climate Variations ◽  
Proxy Data ◽  
Regional Curve Standardization ◽  
The Past ◽  
Tree Ring Data ◽  
Past Climate Variability ◽  
Original Concept

Tree rings are commonly used proxy data for past climate variability. Probably the simplest practical solution for transforming raw tree-ring data into proxy estimates and retaining information on low-frequency tree-growth forcing is the regional curve standardization (RCS). This paper reviews the RCS concept and the development of this standardization method over the past 25 years. Tree-ring based estimation of low-frequency climate variability is illuminated with a growing diversification of the original concept. The RCS-type methods are seen to remain as essential tools in palaeoclimate research while the RCS chronologies of tree-ring and other incremental proxy data remain the only source for calendar year dated short-to-long timescale climate variations.

Reconstructing Past Climatic Anomalies in the North Pacific and Western North America from Tree-Ring Data

1976 ◽  
Vol 6 (4) ◽  
pp. 563-579 ◽  
Author(s):  
T.J. Blasing ◽  
H.C. Fritts
Keyword(s):  
North America ◽  
19Th Century ◽  
Tree Ring ◽  
North Pacific ◽  
Climatic Conditions ◽  
Climatic Data ◽  
Western North America ◽  
The North ◽  
Tree Ring Data ◽  
The North Pacific

Winter climatic anomalies in the North Pacific sector and western North America are statistically calibrated with tree-ring data in western North America and reconstructed back to AD 1700. The results are verified using climatic data from the last half of the 19th century, which is prior to the calibration period. Climatic conditions reconstructed for 18th and 19th century winters are then summarized and compared with the 20th century record.

scholarly journals Supporting Restoration Decisions through Integration of Tree-Ring and Modeling Data: Reconstructing Flow and Salinity in the San Francisco Estuary over the Past Millennium

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2139
Author(s):  
Paul H. Hutton ◽  
David M. Meko ◽  
Sujoy B. Roy
Keyword(s):  
San Francisco ◽  
Tree Ring ◽  
San Francisco Estuary ◽  
Salinity Intrusion ◽  
Estuarine Ecosystem ◽  
Freshwater Flow ◽  
The Past ◽  
Decadal Scale ◽  
Tree Ring Data ◽  
Past Millennium

This work presents updated reconstructions of watershed runoff to San Francisco Estuary from tree-ring data to AD 903, coupled with models relating runoff to freshwater flow to the estuary and salinity intrusion. We characterize pre-development freshwater flow and salinity conditions in the estuary over the past millennium and compare this characterization with contemporary conditions to better understand the magnitude and seasonality of changes over this time. This work shows that the instrumented flow record spans the range of runoff patterns over the past millennium (averaged over 5, 10, 20 and 100 years), and thus serves as a reasonable basis for planning-level evaluations of historical hydrologic conditions in the estuary. Over annual timescales we show that, although median freshwater flow to the estuary has not changed significantly, it has been more variable over the past century compared to pre-development flow conditions. We further show that the contemporary period is generally associated with greater spring salinity intrusion and lesser summer–fall salinity intrusion relative to the pre-development period. Thus, salinity intrusion in summer and fall months was a common occurrence under pre-development conditions and has been moderated in the contemporary period due to the operations of upstream reservoirs, which were designed to hold winter and spring runoff for release in summer and fall. This work also confirms a dramatic decadal-scale hydrologic shift in the watershed from very wet to very dry conditions during the late 19th and early 20th centuries; while not unprecedented, these shifts have been seen only a few times in the past millennium. This shift resulted in an increase in salinity intrusion in the first three decades of the 20th century, as documented through early records. Population growth and extensive watershed modification during this period exacerbated this underlying hydrologic shift. Putting this shift in the context of other anthropogenic drivers is important in understanding the historical response of the estuary and in setting salinity targets for estuarine restoration. By characterizing the long-term behavior of San Francisco Estuary, this work supports decision-making in the State of California related to flow and salinity management for restoration of the estuarine ecosystem.

scholarly journals Cariaco Basin Calibration Update: Revisions to Calendar and 14C Chronologies for Core Pl07-58Pc

Radiocarbon ◽  
2004 ◽  
Vol 46 (3) ◽  
pp. 1161-1187 ◽  
Author(s):  
Konrad A Hughen ◽  
John R Southon ◽  
Chanda J H Bertrand ◽  
Brian Frantz ◽  
Paula Zermeño
Keyword(s):  
Tree Ring ◽  
Cariaco Basin ◽  
Calibration Data ◽  
Data Set ◽  
Varve Chronology ◽  
Pine Tree ◽  
Tree Ring Data ◽  
Calibration Data Set ◽  
Recent Version ◽  
Radiocarbon Calibration

This paper describes the methods used to develop the Cariaco Basin PL07-58PC marine radiocarbon calibration data set. Background measurements are provided for the period when Cariaco samples were run, as well as revisions leading to the most recent version of the floating varve chronology. The floating Cariaco chronology has been anchored to an updated and expanded Preboreal pine tree-ring data set, with better estimates of uncertainty in the wiggle-match. Pending any further changes to the dendrochronology, these results represent the final Cariaco 58PC calibration data set.

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