On the purification of α-cellulose from resinous wood for stable isotope (H, C and O) analysis

α-Cellulose was isolated from four samples of Scots pine (Pinus sylvestris L.). Each sample was divided into two portions. One portion had the resins removed by solvent extraction prior to removal of lignins by treatment with acidic sodium chlorite solution and treatment with sodium hydroxide solution to remove hemicelluloses. The other portion was processed in the same way apart from the solvent extraction step. The isolated wood constituents were characterised by attenuated total reflectance Fourier transform infrared (ATR/FT-IR) spectroscopy. The infrared spectra of the resulting α-cellulose samples were identical indicating that treatment with acidic sodium chlorite and sodium hydroxide was sufficient to remove resins. The values of the stable isotope ratios (carbon, oxygen and hydrogen) for each pair of α-cellulose sub-samples also showed no significant differences within the reproducibility of the methods. The implication of these studies demonstrate that the customary step of resin extraction from pine is unnecessary if sodium chlorite and sodium hydroxide are used for the isolation of α-cellulose following the technique described in this paper. In addition, the study demonstrates that the oxygen isotope ratio of the water used for cellulose extraction does not influence the stable isotope values in the α-cellulose obtained. The importance of isotopic homogeneity within the cellulose sample is also highlighted

Carbon and nitrogen acquisition strategies by wood decay fungi influence their isotopic signatures in Picea abies forests

202

Strategies of carbon and nitrogen acquisition by saprotrophic and ectomycorrhizal fungi in Finnish boreal Picea abies-dominated forests

201

The relationship between needle sugar carbon isotope ratios and tree rings of larch in Siberia

Significant gaps still exist in our knowledge about post-photosynthetic leaf level and downstream metabolic processes and isotopic fractionations. This includes their impact on the isotopic climate signal stored in the carbon isotope composition (delta C-13) of leaf assimilates and tree rings. For the first time, we compared the seasonal delta C-13 variability of leaf sucrose with intra-annual, high-resolution delta C-13 signature of tree rings from larch (Larix gmelinii Rupr.). The trees were growing at two sites in the continuous permafrost zone of Siberia with different growth conditions. Our results indicate very similar low-frequency intra-seasonal trends of the sucrose and tree ring delta C-13 records with little or no indication for the use of 'old' photosynthates formed during the previous year(s). The comparison of leaf sucrose delta C-13 values with that in other leaf sugars and in tree rings elucidates the cause for the reported C-13-enrichment of sink organs compared with leaves. We observed that while the average delta C-13 of all needle sugars was 1.2% more negative than delta C-13 value of wood, the delta C-13 value of the transport sugar sucrose was on an average 1.0% more positive than that of wood. Our study shows a high potential of the combined use of compound-specific isotope analysis of sugars (leaf and phloem) with intra-annual tree ring delta C-13 measurements for deepening our understanding about the mechanisms controlling the isotope variability in tree rings under different environmental conditions.201

Europos izotopų tinklas ISONET: pirmieji rezultatai

Within the EU-Project ISONET (co-ordinator: G. Schleser, http//www.isonet-online.de), 13 partner institutions collaborate to develop the first large-scale network of stable isotopes (C, O and H), integrating 25 European tree sites reaching from the Iberian Peninsula to Fennoscandia. Key species are oak and pine. The sampling design considers not only ecologically “extreme” sites, with mostly a single climate factor dominating tree growth, as supportive for ring width and wood density analyses (Bräuning & Mantwill 2005; Briffa et al. 2001, 2002; Frank & Esper 2005a, b), but also temperate regions with diffuse climate signals recorded in the ‘traditional’ tree ring parameters. Within the project we aim to estimate temperature, humidity and precipitation variations with annual resolution, to reconstruct local to European scale climate variability over the last 400 years. Climate variability is addressed on three timescales, namely decade-century, interannual and intra-annual. This strategy allows understanding of both, high frequency (high resolution exploration of seasonality signals, and extreme events) and longer-term trends (source water/air mass dominance, baseline variability) in site specific and synoptic climate across Europe. Here we present results from initial network analyses considering first data of carbon (δ13C) and oxygen (δ18O) isotopes, to evaluate (a) common patterns in these networks and (b) their potential for detailed climate reconstruction beyond the information commonly achieved from ring width and density analysesVytauto Didžiojo universiteta

Klimato signalai Europos izotopų tnkle ISONET

Over the last three years, 16 European isotope labs collaborated in the EU project ISONET (co-ordinator: G. Schleser, http//www.isonet-online.de) on developing the first large-scale network of 13C, 18O and 2H in from oak, pine and cedar tree-rings, covering sites from Fennoscandia to the Mediterranean region. The sampling design considered not only ecologically “extreme” sites, with a single climate factor predominantly determining tree growth, as required for ring width and wood density analyses (Bräuning & Mantwill 2005, Briffa et al. 2001, 2002, Frank & Esper 2005a, b), but also temperate regions with diffuse climate signals recorded in the ‘traditional’ tree ring parameters. This strategy, however, may enable expanding climatic reconstructions into regions not yet well covered. As reported earlier (Treydte et al. 2005), the aim is to estimate temperature, humidity and precipitation variations with annual resolution, to reconstruct local to European scale climate variability over the last 400 years. Climate variability is addressed on intra-annual to century timescales. This strategy should allow understanding both, high frequency variations including the exploration of seasonality signals and extreme events, and longer-term trends including source water/air mass changes and baseline variability across Europe. Here we present first climate calibration results for the 20th century, using 13C and 18O data from up to 25 sites currently available in the networkVytauto Didžiojo universiteta

NOAA/WDS Paleoclimatology - European Tree-Ring Oxygen Isotope Network from 1600-2013 CE

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Climate Reconstruction. The data include parameters of instrumental with a geographic location of Europe. The time period coverage is from 350 to -70 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data