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

Northern European trees show a progressively diminishing response to increasing atmospheric carbon dioxide concentrations

In order to predict accurately how elevated atmospheric CO2 concentrations will affect the global carbon cycle, it is necessary to know how trees respond to increasing CO2 concentrations. In this paper we examine the response over the period AD 1895 – 1994 of three tree species growing across northern Europe to increases in atmospheric CO2 concentrations using parameters derived from stable carbon isotope ratios of trunk cellulose. Using the isotope data we calculate values of intrinsic water-use efficiency (IWUE) and intercellular CO2 concentrations in the leaf (ci). Our results show that trees have responded to higher levels of atmospheric CO2 by increasing IWUE whilst generally maintaining constant ci values. However, the IWUE of most of the trees in this study has not continued to rise in line with increasing atmospheric CO2. This behaviour has implications for estimations of future terrestrial carbon storage

Mesolithic exploitation patterns in the Central Pennines A palynological study of Soyland Moor

11.00SIGLEAvailable from British Library Lending Division - LD:1863.1856(BAR-BS--139) / BLDSC - British Library Document Supply CentreGBUnited Kingdo