Estimating long-term carbon accumulation rates in boreal peatlands by radiocarbon dating

Abstract

Uses direct radiocarbon dates of peat samples, pollen dates and land-uplift chronology from <1300 cores comprising all or most of the Holocene in the boreal region of Finland, Estonia and Maine to obtain long-term carbon accumulation rates for boreal peatlands. The 'apparent' long-term rate of carbon accumulation (LORCA; g C m-2a-1) ranged from 4.6 to 85.8 (mean 19.9 ± 10.7), depending on the geographical location, wetland type and the age of the mire. The 'true' or 'actual' rate of carbon accumulation (ARCA), as derived from models for peatbog growth, was usually ca 70% of the LORCA. Studies the raised bog Reksuo more intensely in terms of growth dynamics, and reports preliminary results of the 'three-dimensional' or spatial carbon accumulation rates. These results strongly contradict the concept of constant input and constant decay throughout the millennia. The study emphasizes the importance of exploring the formation and dynamics of entire mire ecosystems, and the role of carbon in these systems, in addition to studying single cores.