ABSTRACT
This chapter aims to evaluate the quality of the soil organic matter (SOM) and to determine the distribution of different organic fractions and access the bioreactive fractions in some arctic tundra ecosystems. With moisture and temperature being the major controllers of SOM decomposition, higher decomposition rates would likely result from warming conditions. The primary objectives of the Flux Study are to determine the rates and controls over trace gas fluxes in arctic Alaska and to predict how these fluxes will change in response to climatic warming. Soils studied included Aquepts, Ochrepts, and Histosols where the dominant organic carbon fraction was humic acid, followed in decreasing order by humins, lignins, fulvic acids, and polysaccharides. The low extractability of the organic horizons by alkali solution is attributed to the presence of fresh or partially decomposed organic matter including roots and litter. Conventionally, the alkali-insoluble fraction was considered as humin.
