An investigation of the common signal in tree ring stable isotope chronologies at temperate sites

Abstract

[1] It is currently not well known how coherent carbon and oxygen isotope chronologies from different species and sites are under temperate climate conditions. Here we investigated nine chronologies from Switzerland covering the last two centuries, including three deciduous species (Fagus sylvatica, Fraxinus excelsior, and Quercus petraea) and three conifer species (Abies alba, Picea abies, and Pinus sylvestris) from sites neither strongly limited by temperature nor precipitation. All of the chronologies except Fraxinus were significantly correlated to at least one other chronology. Correlations between different species of the same site were of similar strength to correlations between the sites. We observed a strong common high-frequency (interannual) signal for the d 13 C chronologies, whereas the low-frequency (decadal-scale) signal was more similar among the d 18O chronologies. For both carbon and oxygen isotopes, we found significant positive relationships with annual and growing season temperatures and negative relationships with precipitation, again of similar magnitude for all species except for Fraxinus, which contained only minor climatic information. Averaging of all chronologies resulted in an increase in the climatic signal of the mean chronology. The combined d18 O record reflected decadal-scale temperature variations remarkably well (r = 0.72). However, the relationship between climate and carbon isotopes declined over the last 3 decades of the 20th century, probably related to the steep increase in atmospheric CO 2 concentrations, resulting in strongly diverging d 13 C trends of the different chronologies. Our study indicates that combining chronologies from different species enhances the potential of isotope studies for extending climate reconstructions into areas of temperate climate.

Observed and modeled controls on precipitation δ18O over Europe: From local temperature to the Northern Annular Mode

“…First, the improvements in considering regionally averaged d 18 O from GNIP rather than those at individual stations illustrates the utility of combining multiple, targeted, isotopic archives across a given region. This technique has been applied for Greenland ice cores [White et al, 1997;Rogers et al, 1998] and for tree cellulose [Treydte et al, 2007;Saurer et al, 2008] [36] The NAM-like expression was identified through an empirical analysis of the controls rather than with a single circulation index and a priori assumption of the dominant control. Indeed, as Hurrell et al…”

“…O record, providing a complementary source of reconstruction information [McDermott, 2004;Saurer et al, 2008;Lachniet, 2009].…”

δ13C signature of tree rings and radial increment of Fagus sylvatica trees as dependent on tree neighborhood and climate

“…Drought effects in forests can be enhanced by intraspecific or interspecific competition for water (Gouveia and Freitas 2008) which may be reflected in the chronology of annual tree rings (Saurer et al 2008). Another archive of environmental changes is the tree-ring d 13 C signature.…”

“…Both mechanisms can have consequences for tree growth and the d 13 C signature in the annual rings. Thus, long-term records of these growth and water status proxies can provide valuable insight into a tree's long-term water regime and possibly also into competition-induced changes of the water balance (McNulty and Swank 1995;Buchmann et al 1997;Skomarkova et al 2006;Grams et al 2007;Saurer et al 2008).…”

Climatic sensitivity of δ13C in tree rings of Quercus robur L., Populus tremula L. and Pinus sylvestris L. in Vilnius region (eastern Lithuania)

“…Although strong correlations between isotopic and instrumental data from temperate areas such as Britain (Loader et al, 2003;Loader et al, 2008;Robertson et al, 1997b), Northern France (Etien et al, 2009), Southern Finland (Hilasvuori & Berninger, 2010 and Swiss Central Plateau (Saurer et al, 2008) were evaluated, and only one publication concerning the climate reconstruction of the site neither strongly limited by temperature nor precipitation (temperature in Central England) (Young et al, 2012) was found.…”