The role of amino acids in the nitrogen cycle of peatlands

Future release of carbon from peatlands in response to climate change may be impacted by nitrogen limitation. The current study considers the role of amino acids as a nitrogen source in peatlands. The total free amino acid (TFAA) concentration for peats ranged from 0-2.3 µM, and leucine was the primary contributor. The dominance of sedge or ericaceous shrub plant types did not significantly impact the TFAA pool. Ammonium concentrations were much greater than TFAA and nitrate concentrations. TFAA concentrations were greatest in spring and least in fall. The springtime maxima and summer decrease in concentrations were simulated in a modeling study; however, the model over predicted concentrations. The model was shown to be sensitive to microbial process rates which is likely contributing to model uncertainty. Amino acids may still be considered an important nitrogen source even at low concentrations, and further research on peatland amino acid cycling is needed