scholarly journals Analyses of Great Smoky Mountain Red Spruce Tree Ring Data

1988 ◽  
Author(s):  
Paul C. van Deusen ◽  
[Editor]
Keyword(s):  
Tree Ring ◽  
Red Spruce ◽  
Tree Ring Data ◽  
Great Smoky Mountain

Synchronie large-scale disturbances and red spruce growth decline

1993 ◽  
Vol 23 (7) ◽  
pp. 1361-1374 ◽  
Author(s):  
Gregory A. Reams ◽  
Paul C. Van Deusen
Keyword(s):  
Tree Ring ◽  
Radial Growth ◽  
Large Scale ◽  
Red Spruce ◽  
Southern Appalachians ◽  
Time Interval ◽  
Growth Reduction ◽  
Usda Forest Service ◽  
Tree Ring Data ◽  
Growth Decline

Tree-ring data from the USDA Forest Service Forest Inventory & Analysis and other independent sources were used to study coincidence of changes in growth and large-scale disturbances. Numerous studies report that mean radial growth of red spruce (Picearubens Sarg.) declined synchronously throughout its range in the early 1960s. We use red spruce tree-ring data from most of the major studies to show that the synchronicity of red spruce growth decline is likely the outcome of the large-scale disturbances that occurred throughout the northeastern red spruce ecosystem in the late 1930s to early 1950s. Large-scale disturbances are either not detectable or not present in the same time interval in the southern Appalachians. This appears to correspond to an absence of a 1960s radial growth reduction in this region.

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.

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

<p>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 (Δ<sup>13</sup>C) and oxygen (δ<sup>18</sup>O) stable isotopes in six sites in boreal and temperate Europe.  The model simulates Δ<sup>13</sup>C (r = 0.31-0.80) and δ<sup>18</sup>O (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 δ<sup>18</sup>O combine physiological effects and climate variability impacts on source water signatures. The integration of tree-ring data (i.e. the triple constraint: width, Δ<sup>13</sup>C and δ<sup>18</sup>O) and land surface models as demonstrated here should contribute towards reducing current uncertainties in forest carbon and water cycling.</p>

scholarly journals A 368-year maximum temperature reconstruction based on tree-ring data in the northwestern Sichuan Plateau (NWSP), China

2016 ◽  
Vol 12 (7) ◽  
pp. 1485-1498 ◽  
Author(s):  
Liangjun Zhu ◽  
Yuandong Zhang ◽  
Zongshan Li ◽  
Binde Guo ◽  
Xiaochun Wang
Keyword(s):  
Tree Ring ◽  
Land Surface ◽  
Temperature Reconstruction ◽  
Temperature Variability ◽  
Ice Age ◽  
Maximum Temperature ◽  
Tree Ring Data ◽  
The Mean ◽  
Extreme Cold ◽  
The 19Th Century

Abstract. We present a reconstruction of July–August mean maximum temperature variability based on a chronology of tree-ring widths over the period AD 1646–2013 in the northern part of the northwestern Sichuan Plateau (NWSP), China. A regression model explains 37.1 % of the variance of July–August mean maximum temperature during the calibration period from 1954 to 2012. Compared with nearby temperature reconstructions and gridded land surface temperature data, our temperature reconstruction had high spatial representativeness. Seven major cold periods were identified (1708–1711, 1765–1769, 1818–1821, 1824–1828, 1832–1836, 1839–1842, and 1869–1877), and three major warm periods occurred in 1655–1668, 1719–1730, and 1858–1859 from this reconstruction. The typical Little Ice Age climate can also be well represented in our reconstruction and clearly ended with climatic amelioration at the late of the 19th century. The 17th and 19th centuries were cold with more extreme cold years, while the 18th and 20th centuries were warm with less extreme cold years. Moreover, the 20th century rapid warming was not obvious in the NWSP mean maximum temperature reconstruction, which implied that mean maximum temperature might play an important and different role in global change as unique temperature indicators. Multi-taper method (MTM) spectral analysis revealed significant periodicities of 170-, 49–114-, 25–32-, 5.7-, 4.6–4.7-, 3.0–3.1-, 2.5-, and 2.1–2.3-year quasi-cycles at a 95 % confidence level in our reconstruction. Overall, the mean maximum temperature variability in the NWSP may be associated with global land–sea atmospheric circulation (e.g., ENSO, PDO, or AMO) as well as solar and volcanic forcing.

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 Debris-flow activity in abandoned channels of the Manival torrent reconstructed with LiDAR and tree-ring data

2011 ◽  
Vol 11 (5) ◽  
pp. 1247-1257 ◽  
Author(s):  
J. Lopez Saez ◽  
C. Corona ◽  
M. Stoffel ◽  
A. Gotteland ◽  
F. Berger ◽  
...  
Keyword(s):  
Debris Flow ◽  
Tree Ring ◽  
Debris Flows ◽  
Temporal Distribution ◽  
Alluvial Fan ◽  
Tree Ring Data ◽  
Pine Trees ◽  
Spatio Temporal ◽  
Flow Activity ◽  
Abandoned Channels

Abstract. Hydrogeomorphic processes are a major threat in many parts of the Alps, where they periodically damage infrastructure, disrupt transportation corridors or even cause loss of life. Nonetheless, past torrential activity and the analysis of areas affected during particular events remain often imprecise. It was therefore the purpose of this study to reconstruct spatio-temporal patterns of past debris-flow activity in abandoned channels on the forested cone of the Manival torrent (Massif de la Chartreuse, French Prealps). A Light Detecting and Ranging (LiDAR) generated Digital Elevation Model (DEM) was used to identify five abandoned channels and related depositional forms (lobes, lateral levees) in the proximal alluvial fan of the torrent. A total of 156 Scots pine trees (Pinus sylvestris L.) with clear signs of debris flow events was analyzed and growth disturbances (GD) assessed, such as callus tissue, the onset of compression wood or abrupt growth suppression. In total, 375 GD were identified in the tree-ring samples, pointing to 13 debris-flow events for the period 1931–2008. While debris flows appear to be very common at Manival, they have only rarely propagated outside the main channel over the past 80 years. Furthermore, analysis of the spatial distribution of disturbed trees contributed to the identification of four patterns of debris-flow routing and led to the determination of three preferential breakout locations. Finally, the results of this study demonstrate that the temporal distribution of debris flows did not exhibit significant variations since the beginning of the 20th century.

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