Carbon and nitrogen stoichiometry and nitrogen cycling rates in streams

• Published in: Oecologia
• Main Authors: Dodds, W. K., Martí, Eugènia, Tank, J. L., Pontius, J., Hamilton, S. K., Grimm, N. B., Bowden, W. B., McDowell, W. H., Peterson, B. J., Valett, H. M., Webster, J. R., Gregory, S. V.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2004
• Subjects: Carbon; Carbon:Nitrogen ratio; Nitrogen; Stoichiometry; Streams; Tundra
• Online Access: http://hdl.handle.net/10261/37392; https://doi.org/10.1007/s00442-004-1599-y

10 Páginas 4 Tablas 3 Figuras 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. The research was supported by the United States National Science Foundation, LINX and the Konza Long-Term Ecological Research grant. This is publication 01-147-J from the Kansas Agricultural Experiment Station. Peer reviewed