Dynamic standardization of tree-ring series

1990 ◽  
Vol 20 (9) ◽  
pp. 1422-1431 ◽  
Author(s):  
William G. Warren ◽  
David C. LeBlanc

The compound growth function of Warren (W.G. Warren. 1980. Tree-Ring Bull. 40: 35–44) represented an attempt at developing a model-based approach that standardized tree ring width sequences and was more flexible than the monotonic functions that were then commonly used. While the idea was conceptually attractive, operational difficulties of fitting hindered its use as a practical tool. This paper describes the modifications, and what are believed to be improvements, that have recently been made to the method, and which have led to an interactive computer program by which the fitting of the model to any sequence of ring widths may be readily accomplished. The approach also permits the location of both positive and negative departures from a trend (releases and suppressions, respectively) and estimation of the rate of ring-width increase or decrease. For illustration it has been applied to a sample of red spruce (Picearubens Sarg.) cores from Whiteface Mountain, New York. Some synchrony in releases and suppressions was detected, with suppressions being very conspicuous since the late 1950s. Also, the recent reductions in growth rates are as great, or greater, than those previously exhibited by the trees of this sample.

1990 ◽  
Vol 20 (9) ◽  
pp. 1399-1407 ◽  
Author(s):  
David C. LeBlanc

This paper describes relationships between tree growth indices based on ring width measurements at 1.4 m aboveground and indices derived from whole-stem analysis for red spruce (Picearubens Sarg.) in a high-elevation spruce-fir forest on Whiteface Mountain, New York. Coefficients of determination for linear regressions between mean, standardized chronologies for breast-height ring width versus whole-stem ring width and basal area increment versus annual volume increment are 0.89 and 0.93, respectively. However, substantial variability is apparent in breast-height versus whole-stem relationships for individual trees, particularly for unstandardized growth indices. Also, relationships between unstandardized growth indices exhibit temporal instability associated with individual tree maturation and stand dynamics. Nonetheless, strong relationships between mean standardized chronologies of breast-height and whole-stem growth indices validate the use of breast-height growth indices to represent year-to-year variation in mean growth performance of red spruce. A volume-equation-based procedure is described that provides better dendrochronological estimates of annual volume increment than estimates based on basal area increment alone.


2021 ◽  
Vol 303 ◽  
pp. 108394
Author(s):  
Nathsuda Pumijumnong ◽  
Piyarat Songtrirat ◽  
Supaporn Buajan ◽  
Sineenart Preechamart ◽  
Uthai Chareonwong ◽  
...  

2010 ◽  
Vol 29 (17-18) ◽  
pp. 2111-2122 ◽  
Author(s):  
X. Shao ◽  
Y. Xu ◽  
Z.-Y. Yin ◽  
E. Liang ◽  
H. Zhu ◽  
...  

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire

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.


The Holocene ◽  
2021 ◽  
pp. 095968362110116
Author(s):  
Jeroen DM Schreel

Over the last few decades – at a range of northern sites – changes in tree-ring width and latewood density have not followed mean summertime temperature fluctuations. This discrepancy sharply contrasts an earlier correlation between those variables. As the origin of this inconsistency has not been fully deciphered, questions have emerged regarding the use of tree-ring width and latewood density as a proxy in dendrochronological climate reconstructions. I suggest that temperature is no longer the most limiting factor in certain boreal areas, which might explain the observed divergence.


Ecology ◽  
1936 ◽  
Vol 17 (3) ◽  
pp. 457-478 ◽  
Author(s):  
Charles J. Lyon

2014 ◽  
Vol 10 (2) ◽  
pp. 437-449 ◽  
Author(s):  
P. Breitenmoser ◽  
S. Brönnimann ◽  
D. Frank

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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