Publication Date:
2016-07-26
Description:
Considering recent increases in anthropogenic N loading it is essential to identify the controls on N removal and retention in aquatic ecosystems because the fate of N has consequences for water quality in streams and downstream ecosystems. Biological uptake of nitrate (NO 3 - ) is a major pathway by which N is removed from these ecosystems. Here we used data from the second Lotic Intersite Nitrogen eXperiment (LINX II) in a multivariate analysis to identify the primary drivers of variation in NO 3 - uptake velocity among biomes. Across 69 study watersheds in North America, DOC:NO 3 - ratios and photosynthetically active radiation were identified as the two most important predictor variables in explaining NO 3 - uptake velocity. However, within a specific biome the predictor variables of NO 3 - uptake velocity varied, and included various physical, chemical and biological attributes. . Our analysis demonstrates the broad control of elemental stoichiometry on NO 3 - uptake velocity as well as the importance of biome-specific predictors. Understanding this spatial variation has important implications for biome-specific watershed management and the downstream export of NO 3 - , as well as for development of spatially explicit global models that describe N dynamics in streams and rivers.
Print ISSN:
0886-6236
Electronic ISSN:
1944-9224
Topics:
Biology
,
Chemistry and Pharmacology
,
Geography
,
Geosciences
,
Physics
