Gill, A. L., R. M. Grinder, C. R. See, F. S. Chapin, L. C. DeLancey, M. C. Fisk, P. M. Groffman, T. Harms, S. E. Hobbie, J. D. Knoepp, J. M. Knops, M. Mack, P. B. Reich, and A. D. Keiser. 2023. Soil carbon availability decouples net nitrogen mineralization and net nitrification across United States Long Term Ecological Research sites. Biogeochemistry 162:13-24.
Autotrophic and heterotrophic organisms require resources in stoichiometrically balanced ratios of carbon © to nutrients, the demand for which links organismal and ecosystem-level biogeochemical cycles. In soils, the relative availability of C and nitrogen (N) also defines the strength of competition for ammonium between autotrophic nitrifiers and heterotrophic decomposers, which may influence the coupled dynamics between N mineralization and nitrification. Here, we use data from the publicly available US National Science Foundation funded Long Term Ecological Research (LTER) network to evaluate the influence of soil C concentration on the relationship between net nitrification and net N mineralization. We found that soil C availability constrains the fraction of mineralized N that is ultimately nitrified across the continental gradient, contributing to reduced rates of nitrification in soils with high C concentrations. Nitrate, which is produced by nitrification, is a highly mobile ion that easily leaches to aquatic ecosystems or denitrifies into the greenhouse gas nitrous oxide (N2O). Understanding the connection between soil C concentration and soil N transformations is thus important for managing potential ecosystem N losses, understanding the biogeochemical constraints of these losses, and accurately representing coupled C-N dynamics in ecosystem models
Associated Treatment Areas:
Cross Site SynthesisSign in to download PDF back to index