| Summary: | Increases in temperature and nutrient availability may accelerate soil organic matter (SOM) decomposition while organo-mineral interactions may potentially stabilize SOM components. After 32 years of warming, nitrogen and phosphorus (N+P) fertilization, and the combined treatment, SOM degradation was not significantly enhanced in Arctic soils. Considerable variability in the biomarker data may be attributable to spatial heterogeneity among the blocks. In the second project, biomarker investigations indicated that mineral interactions likely protect lignin from extraction. Suberin and cutin protection of lignin was not observed until after clay mineral dissolution by hydrofluoric acid (HF). This suggests that clay mineral interactions may play a more dominant role in the protection of lignin than interactions with suberin and cutin. Overall, this thesis demonstrates that biomarker methods can show how the distribution of SOM may be reflective of topographical patterns and can provide further evidence that mineral protection mechanisms help stabilize SOM components. M.Sc. 2018-12-15 00:00:00
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