The Role of Soil Organic Matter and Manures in Sustainable Nutrient Cycling - Sustainable Management of Soil Organic Matter - page 326

species in all soils, but is highest in the south. Increasing b5ca/b6ca ratios to
the north indicate a decreasing degree of condensation.
The profile pattern of

15 N (Fig. 4.14.4) contrasts with
the chemical analysis of SOM, if only aerobic decomposition processes are

δ

13 C and

δ

Fig. 4.14.3. Composition of SOM in soils of the forest tundra, northern taiga and central taiga
with respect to lignin-derived phenols, microbial-derived amino sugars and pyrogenic C (for details,
see Methods).