Possibility using carbon-to-nitrogen ratio as a criterion for palsa and lithalsa distinguishing

Abstract

The palsa and lithalsa are reliable indicators of the presence of permafrost, especially on the its southern border. The subject of the study is the consideration of the C/N ratio in the peat of the palsa and the litter and humus horizon of the lithalsa as a criterion for the separation of the palsa and lithalsa. The palsa near the Yeletskaya village in the Bolshezemelskaya tundra and the lithalsa in the Southern Transbaikalia near the Preobrazhenka village and in the valley of the Sentsa in the Eastern Sayan are considered. The history of the study of lithalsa and palsa in Russia at the beginning of the twentieth century is considered also. It was found that the nitrogen content in the surface layers of the lithalsa (0.45-1.73% in the valley of the Sentsa River and 0.47-2.01% near the Arachley Lake) is approximately in the same range as in the surface horizons of the palsa, regardless of the permafrost region. The results of the carbon and nitrogen content determining, as well as their ratios in the peat cover of the palsa are summarized. In contrast to lithalsa, the carbon content in the peat horizons of the palsa and flat-hummock peatlands is many times higher than the values obtained for both surface and buried organic horizons of the lithalsa. The value of C/N less than 13 has not been recorded for the peat cover of palsa, this indicator for lithalsa never exceeds 10-12.