Chinese pine (Pinus tabulaeformis) trees were sampled in the Helan Mountain, northwest China. The stable carbon isotope (delta(13)C) values of whole wood, holocellulose and alpha-cellulose in tree rings over 30 years (1968-1997) were measured to study the delta(13)C response of different tree-ring components to past environmental change. There were obvious differences in the delta(13)C values of the three components. The Pearson correlation coefficient between the delta(13)C of alpha-cellulose and that of holocellulose was 0.547 (rho < 0.01); between alpha-cellulose and whole wood, the coefficient was -0.126 (rho > 0.10); between holocellulose and whole wood, the coefficient was -0.056. Correlation function analyses indicated that the delta(13)C content of tree-ring alpha-cellulose correlated strongly with the average temperature from June to August (r = 0.427, rho < 0.05), more than that of holocellulose (0.324, rho < 0.10) or total wood (-0.245, rho > 0.10). Significant correlations were observed between delta(13)C of tree-ring alpha-cellulose and the precipitation from the current year's February to July (r = -0.514, rho < 0.01) that were much higher than that of holocellulose (-0.481, rho < 0.05) or total wood (-0.249, rho > 0.10). A significant correlation (-0.545, rho < 0.01) was also found between the ring width and the delta(13)C residual chronologies. These results suggest that more past environmental information is retained in the delta(13)C of tree-ring alpha-cellulose. Thus, the delta(13)C of alpha-cellulose of tree rings is the most suitable among the studied parameters for reconstructing the past climatic conditions during the growing season. The delta(13)C values of other organic compounds in Pinus tabulaeformis xylem were affected by the external environment after carbon was fixed from the atmosphere.
The environmental signals of stable carbon isotope in various tree-ring components of Pinus tabulaeformis
LORENZINI, GIACOMO
2011-01-01
Abstract
Chinese pine (Pinus tabulaeformis) trees were sampled in the Helan Mountain, northwest China. The stable carbon isotope (delta(13)C) values of whole wood, holocellulose and alpha-cellulose in tree rings over 30 years (1968-1997) were measured to study the delta(13)C response of different tree-ring components to past environmental change. There were obvious differences in the delta(13)C values of the three components. The Pearson correlation coefficient between the delta(13)C of alpha-cellulose and that of holocellulose was 0.547 (rho < 0.01); between alpha-cellulose and whole wood, the coefficient was -0.126 (rho > 0.10); between holocellulose and whole wood, the coefficient was -0.056. Correlation function analyses indicated that the delta(13)C content of tree-ring alpha-cellulose correlated strongly with the average temperature from June to August (r = 0.427, rho < 0.05), more than that of holocellulose (0.324, rho < 0.10) or total wood (-0.245, rho > 0.10). Significant correlations were observed between delta(13)C of tree-ring alpha-cellulose and the precipitation from the current year's February to July (r = -0.514, rho < 0.01) that were much higher than that of holocellulose (-0.481, rho < 0.05) or total wood (-0.249, rho > 0.10). A significant correlation (-0.545, rho < 0.01) was also found between the ring width and the delta(13)C residual chronologies. These results suggest that more past environmental information is retained in the delta(13)C of tree-ring alpha-cellulose. Thus, the delta(13)C of alpha-cellulose of tree rings is the most suitable among the studied parameters for reconstructing the past climatic conditions during the growing season. The delta(13)C values of other organic compounds in Pinus tabulaeformis xylem were affected by the external environment after carbon was fixed from the atmosphere.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
