通过树木年轮δ^(13)C重建大气CO_2碳同位素比δa的可靠性探讨

摘要

Based on the experimental results from seven subtropical species,in contrast with other researchers′ results, the parameter Ci/Ca (ratio of substomatal CO 2 to atmospheric CO 2 concentration)is not stable,but varies with species and environmental factors,especially light intensity.Thus,we concluded that the use of tree ring isotope ratios in the reconstruction of atmospheric CO 2 isotope ratio δa variation,which is based on the assumption that Ci/Ca keeps stable during assimilation,is not reliable under current circumstances.