Temperature sensitivity of blue intensity, maximum latewood density, and ring width data of living black spruce trees in the eastern Canadian taiga

Tropical volcanoes synchronize eastern Canada with Northern Hemisphere millennial temperature variability

“…1 ) and better-constrained uncertainties (Fig. 2c ), due to the enhanced sensitivity of MXD data to high-frequency temperature variability 5 , 11 , 21 ( r D-STREC = 0.72 vs. r 3P-STREC = 0.40 with the 10-year high-pass temperature target). Furthermore, D-STREC agrees nicely with the historical record at 1816 CE following the 1815 CE Tambora eruption, although the recovery is one year longer for sites farther north (Supplementary Fig.…”

“…The RSFi method efficiently removed nonclimatic signals (e.g., local competition and disturbances) introduced by trees established in different eras, while preserving the long-term variability. In addition, because the MXD series of black spruce trees are known to exhibit heteroscedastic variance 21 , we compared chronologies calculated from ratios and residuals plus power-transformation 52 via a time-efficient linear scaling reconstruction approach 53 . The RSFi ratio chronologies were chosen for the final D-STREC temperature reconstruction due to better overall performance (Supplementary Method 2 ).…”

Blue is the fashion in Mediterranean pines: New drought signals from tree-ring density in southern Europe

“…To our knowledge, this is the first study analyzing the potential of blue intensity variables for their applications in dendroclimatic or dendroecological research under Mediterranean conditions. Previous studies exploring the usefulness of the BI data were mainly carried out in higher latitudes with temperature being the strongest growth limiting factor (Björklund et al, 2014;Seftigen et al, 2020;Wang et al, 2020). Under the presented growing conditions, BI series have been found to be a better proxy than conventional tree-ring series for dendroclimatic analyses, especially for populations at lower elevations (Figs.…”

“…Climate-growth relationships revealed differences both in climatic signal type and intensity between the measured BI and RW related variables, and this difference was found to be more pronounced at LES. The BI series can be interpreted as density values of the tree ring, due to strong similarities (Campbell et al, 2007) or sometimes indistinguishability among both (Wang et al, 2020), and are related to the relationship between cell wall thickness to the cell (tracheid) size (Björklund et al, 2021). With the smaller cell lumina and thicker wall (i.e., higher density), the water conductance efficiency is decreasing, but the mechanical strength and resistance to hydraulic failure is enhanced (Hacke et al, 2006;Pellizzari et al, 2016).…”

Experiments of the efficacy of tree ring blue intensity as a climate proxy in central and western China

“…Compared to WinDENDRO TM , a lower cost alternative for measuring BI has been incorporated into the CooRecorder/CDendro software package, 45 by which several experiments (Rydval et al, 2014;Wilson et al, 2012;Wilson et al, 2014) have been conducted with this approach now becoming more and more popular in the tree ring community (Kaczka and Wilson, 2021). BI-based tree ring research, focusing on both climate and ecological based studies, have been widely carried out in Europe (Helama et al, 2013;Babst et al, 2009;Mccarroll et al, 2002;Campbell et al, 50 2007;Rydval et al, 2014;Dolgova, 2016;Fuentes et al, 2018) and North America (Wilson et al, 2014;Wiles et al, 2019;Harley et al, 2021;Heeter et al, 2021;Wilson et al, 2019;Wang et al, 2020).…”