Frequency-dependent signals in multi-centennial oak vessel data

Abstract

This work evaluates whether vessel size data contain a coherent spring precipitation signal over different frequency domains, and how this climatic information varies from the signal encoded in radial growth. The study was conducted at a forest site dominated by old oak trees (Quercus petraea (Mattuschka) Liebl.) located in the southern part of the Swiss Alps.Measurements of earlywood vessel size of 27 cores from 12 oak trees were performed in order to build an unprecedented multi-centennial vessel size chronology. Age-independent long-term growth changes and climatic responses in the high-, mid-and low-frequency domains of differently composed chronologies are explored to test the stability of the signals.Results are compared with analyses of tree-ring width measurements from the same material to gain a deeper understanding of physiological processes. We find that mean vessel size data, in contrast to tree-ring width, carry a frequency-dependent signal. Although the signal of both parameters is similar in the low-frequency domain, the climate response in the high-frequency domain differs: vessel size responds negatively to wet spring conditions, whereas ring width mainly responds positively to water availability during the summer. We hypothesize that the processes responsible for signal registration in the specific frequencies are different. The differing high-frequency signals appear to be directly linked to dissimilar responses to weather conditions driving ring and vessel formation. In contrast, the long-term response is related to conditions that affect tree vigour and, due to a positive feedback on growth, is indirectly reflected in the vessels and ring width characteristics. Due to the change in the frequency related response observed in this pioneering study, it appears that the mean earlywood vessel size of oak is not an adequate proxy for long-term reconstruction of spring precipitation.

Specific climatic signals recorded in earlywood and latewood δ¹⁸O of tree rings in southwestern China

“…The y-axis for each parameter has been standardized to be dimensionless. environmental factors such as climate conditions during xylem development can also affect the anatomical features of woody tissues (Fonti et al, 2009). For tree-ring cellulose d…”

Do High-Elevation Northern Red Oak Tree-Rings Share a Common Climate-Driven Growth Signal?

“…tree-ring records developed from temperate and Mediterranean regions, open-canopy high-elevation northern red oak tree-ring records hold the potential for evaluating decadal climate variability over the past four centuries across the Southern Appalachian region. Disentangling the apparent time-dependent mixed temperature-precipitation signal retained in high-elevation northern red oak ring-width represents a challenge that will likely require an intra-seasonal examination of vesselwood-latewood variance, especially relationships to seasonal climate variability and/or possible frequency-dependent climate responses contained therein (e.g., Gonzalez and Eckstein, 2003;Fonti et al, 2009). It is important to note that although future hydroclimate change remains uncertain for the southeastern United States in response to climatic warming (e.g., Seager et al, 2009), this study points out that temperature change across the Southern Appalachian region may have differential effects on winter and summer precipitation seasonality, and if so, tree-ring records may have difficulty resolving this change clearly.…”

“…This common signal is possibly tied to the variance spectrum of the regional climate growth control, but since much of northern red oak's growth lacks significant high-frequency variability, a frequency-dependent bias may be present within these records making it more challenging to calibrate interannual temperature and precipitation variability with ring-width (e.g., Fonti et al, 2009). …”

Influence of climate on tree-ring and earlywood vessel formation in Quercus robur in Latvia

“…Since the 1970s with the progress of digital technologies and automation of measurements, the use of anatomical structures of wood has gained importance in dendrochronology (Eckstein and Frisse 1982;Fonti et al 2009aFonti et al , 2010Woodcock 1989). Wood anatomical proxies, such as earlywood vessel (EV) parameters, can provide additional information about climatic factors, which are not evident in tree-ring width series (Fonti et al 2009b(Fonti et al , 2010Matisons and Dauškane 2009).…”