C: N: P stoichiometry as an indicator of Histosol drainage in lowland and mountain forest ecosystems

  Background  Peatlands form one of the largest carbon pools in the terrestrial ecosystems, representing approximately one-third of the world's soil carbon. The aim of this study was to evaluate C: N: P stoichiometry as an indicator of changes initialized by dehydration in Histosols of varied origins. Four types of Histosols from lowland and mountain areas were investigated: fibric Histosols, hemic Histosols, sapric Histosols and Histosols drainic.

  Results  We established the concentration and stoichiometry of carbon, nitrogen and phosphorous in the Histosols, and found marked differences in C: N: P stoichiometry between the different types-especially the dehydrated samples. The mean C: N: P ratio of dehydrated soil was narrower than the C: N: P ratio of soil under the influence of water, which demonstrates that dehydrating Histosols leads to a narrower C: N: P stoichiometry. This is directly related to the intensification of the organic matter mineralisation process and the resulting loss of organic carbon. We recorded a 50 % lower carbon stock in the case of Histosols drainic compared to the other types of Histosols.

  Conclusions  The narrower C: N: P stoichiometry in Histosols drainic is the result of an decrease in the ratio of N and P to the C content. Thus, this study demonstrates that C: N: P stoichiometry is a useful indicator of the changes that occur in Histosols as a result of dehydration.