Regional And Watershed-Scale Coherence In the Stable-Oxygen and Carbon Isotope Ratio Time Series In Tree Rings Of Coast Redwood (Sequoia sempervirens)

Abstract

Coast redwood (Sequoia sempervirens) ecosystems are strongly influenced by the presence of summer marine fog, and variation in fog frequency is closely linked to climate variation in the NE Pacific region. Because oxygen isotope composition (d 18 O) of organic matter records distinct water sources (e.g. summertime fog vs. winter precipitation) and carbon isotopes (d 13 C) are typically sensitive to humidity and water status, it then follows that inter-annual variation in tree-ring isotope ratios, which are coherent across multiple sites, should preserve a potentially powerful proxy for climate reconstruction. Here we present an analysis of a 50-year time series for both d 18 O and d 13 C values from subdivided tree rings obtained from multiple redwood trees at multiple sites. Within-site and betweensite correlations were highly significant (p , 0.01) for the d 18 O time series indicating a regionally coherent common forcing of d 18 O fractionation. Within-site and between-site correlation coefficients were lower for the d 13 C than for the d 18 O time series although most were still significant (at least to p , 0.05). The hypothesized reason for the differences in the correlation is that carbon isotope discrimination is more sensitive to microenvironmental and tree-level physiological variation than is d 18 O fractionation. Stable-isotope variation in tree-ring cellulose was similar between slope, gully and riparian micro-habitats within a single watershed, implying that minor topographic variation when sampling should not be a major concern. These results indicate that stable-isotope time series from redwood tree rings are strongly influenced by regional climate drivers and potentially valuable proxies for Pacific coastal climate variability.

Assessing tree-ring carbon and oxygen stable isotopes for climate reconstruction in the Canadian northeastern boreal forest

“…Even if some authors have reported a high natural variability between individual δ 18 O series (e.g., Szymczak et al, 2012), important variabilities between individual δ 13 C series have been also documented for different deciduous and coniferous species in previous studies (Saurer et al, 1997b;Masson-Delmotte et al, 2004;Raffalli-Delerce et al, 2004;Roden et al, 2011). This phenomenon suggests a sensitivity of carbon isotopes to environmental conditions surrounding each sampled tree.…”

Oxygen and carbon stable isotopes in coast redwood tree rings respond to spring and summer climate signals

“…[10] Tree cores for this study come from three separate sites in classic redwood habitat along 100 km of the Northern California coastline. The sites and trees used for this study are identical to those used by Roden et al [2009Roden et al [ , 2011. Excluded from the present work is one site from Sonoma, CA, located~300 km to the south, determined to be a statistical outlier from the three sites used here [Roden et al, 2011].…”

Series de incremento del área basal en árboles dominantes de Pseudotsuga menziesii (Mirb.) Franco muestran periodicidad de acuerdo con patrones climáticos globales

“…El análisis de serie de tiempo de la especie abeto Douglas ayudaría a confirmar los eventos extremos pasados en patrones de circulación atmosférica, escasez de recursos hídricos e impacto socioeconómico en la población (Cerano et al, 2011;Návar & Lizárraga-Mendiola, 2013). Recientemente, el uso del análisis de series de tiempo, combinado con isótopos de madera, y la dendrocronología han demostrado ser útiles para describir la relación de la fisiología de los árboles y la variabilidad del clima de acuerdo con el aumento de CO 2 atmosférico (Monserud & Marshall, 2001;Roden, Johnstone, & Dawson, 2011;Swetnam & Lynch, 1993).…”

“…Time series analysis of tree species like Douglas-fir would also help to confirm extreme past events in atmospheric circulation patterns, water resources shortage, and its socioeconomic impact on the population (Cerano et al, 2011;Návar & Lizárraga-Mendiola, 2013). More recently, the use of time series analysis combined with wood isotopes and dendrochronology have showed to be useful to describe the relationship of tree physiology and climate variability according to increased atmospheric CO 2 (Monserud & Marshall, 2001;Roden, Johnstone, & Dawson, 2011;Swetnam & Lynch, 1993).…”