Carbon and nitrogen stoichiometry and nitrogen cycling rates in streams.

Academic Article

Abstract

  • Stoichiometric analyses can be used to investigate the linkages between N and C cycles and how these linkages influence biogeochemistry at many scales, from components of individual ecosystems up to the biosphere. N-specific NH4+ uptake rates were measured in eight streams using short-term 15N tracer additions, and C to N ratios (C:N) were determined from living and non-living organic matter collected from ten streams. These data were also compared to previously published data compiled from studies of lakes, ponds, wetlands, forests, and tundra. There was a significant negative relationship between C:N and N-specific uptake rate; C:N could account for 41% of the variance in N-specific uptake rate across all streams, and the relationship held in five of eight streams. Most of the variation in N-specific uptake rate was contributed by detrital and primary producer compartments with large values of C:N and small values for N-specific uptake rate. In streams, particulate materials are not as likely to move downstream as dissolved N, so if N is cycling in a particulate compartment, N retention is likely to be greater. Together, these data suggest that N retention may depend in part on C:N of living and non-living organic matter in streams. Factors that alter C:N of stream ecosystem compartments, such as removal of riparian vegetation or N fertilization, may influence the amount of retention attributed to these ecosystem compartments by causing shifts in stoichiometry. Our analysis suggests that C:N of ecosystem compartments can be used to link N-cycling models across streams.
  • Authors

  • Dodds, Walter K
  • Martí, Eugenia
  • Tank, Jennifer L
  • Pontius, Jeffrey
  • Hamilton, Stephen K
  • Grimm, Nancy B
  • Bowden, William B
  • McDowell, William
  • Peterson, Bruce J
  • Valett, H Maurice
  • Webster, Jackson R
  • Gregory, Stan
  • Status

    Publication Date

  • August 2004
  • Published In

  • Oecologia  Journal
  • Keywords

  • Carbon
  • Ecosystem
  • Environmental Monitoring
  • Nitrogen
  • Nitrogen Isotopes
  • Rivers
  • Digital Object Identifier (doi)

    Pubmed Id

  • 15179578
  • Start Page

  • 458
  • End Page

  • 467
  • Volume

  • 140
  • Issue

  • 3