Plant stable-carbon isotope fractionation models indicate that δ13C of atmospheric CO2, CO2 concentration, light and moisture stress, among other factors, may potentially affect the δ13C of fixed carbon. Seasonal δ13C variations in tree rings may therefore represent a new tool for paleoenvironmental reconstruction. The seasonal δ13C patterns in growth rings exist in trees (conifer and hardwood) from tropical and temperate localities, and isotopic variation is even seen in trees which are lacking or have poorly-defined rings. The patterns in different rings from a single tree are usually similar, although differences in amplitude and timing of maxima and/or minima are common. Some of the differences may be attributable to radial variation of the δ13C patterns which was found to be substantial in a severely water-stressed tree. Correlations of δ13C patterns and corresponding seasonal environmental variation for one well-monitored tree showed greater response of the δ13C change to measured soil moisture and precipitation than to temperature, calculated soil moisture, solar radiation, or net photosynthesis (as estimated from CO2 release).
ASJC Scopus subject areas
- Environmental Science(all)
- Earth and Planetary Sciences(all)