• Carbon Isotope Measurement as an Index of Soil Development

      Ladyman, S. J.; Harkness, D. D. (American Journal of Science, 1980-01-01)
      14C and 13C enrichment values are reported for a series of surface soil profiles which represent the progressive transition from mor to mull humus induced by birch (Betula pendula) colonization. Variations in Deltaand delta-13C, which range between 85 to 154 ppm modern and -28.1 to -25.3 ppm (PDB), respectively, reflect changes in the rate and mode of organic decomposition. The most marked alterations in soil character occur over the first few decades following the introduction of birch, with clear isotopic evidence for the deeper penetration and accelerated mineralization of organic material.