Nitrogen saturation in stream ecosystems

Simple item page
dc.contributor.authorEarl, S. R.en
dc.contributor.authorValett, H. M.en
dc.contributor.authorWebster, Jackson R.en
dc.contributor.departmentBiological Sciencesen
dc.date.accessed2014-03-11en
dc.date.accessioned2014-03-27T13:06:00Zen
dc.date.available2014-03-27T13:06:00Zen
dc.date.issued2006-12en
dc.description.abstractThe concept of nitrogen (N) saturation has organized the assessment of N loading in terrestrial ecosystems. Here we extend the concept to lotic ecosystems by coupling Michaelis-Menten kinetics and nutrient spiraling. We propose a series of saturation response types, which may be used to characterize the proximity of streams to N saturation. We conducted a series of short-term N releases using a tracer ((NO3)-N-15-N) to measure uptake. Experiments were conducted in streams spanning a gradient of background N concentration. Uptake increased in four of six streams as NO3-N was incrementally elevated, indicating that these streams were not saturated. Uptake generally corresponded to Michaelis-Menten kinetics but deviated from the model in two streams where some other growth-critical factor may have been limiting. Proximity to saturation was correlated to background N concentration but was better predicted by the ratio of dissolved inorganic N ( DIN) to soluble reactive phosphorus (SRP), suggesting phosphorus limitation in several high-N streams. Uptake velocity, a reflection of uptake efficiency, declined nonlinearly with increasing N amendment in all streams. At the same time, uptake velocity was highest in the low-N streams. Our conceptual model of N transport, uptake, and uptake efficiency suggests that, while streams may be active sites of N uptake on the landscape, N saturation contributes to nonlinear changes in stream N dynamics that correspond to decreased uptake efficiency.en
dc.description.sponsorshipNational Science Foundation (DEB 0206443)en
dc.description.sponsorshipVirginia Academy of Scienceen
dc.description.sponsorshipVirginia Polytechnic Institute and State Universityen
dc.identifier.citationStevan R. Earl, H. Maurice Valett, and Jackson R. Webster 2006. NITROGEN SATURATION IN STREAM ECOSYSTEMS. Ecology 87:3140-3151. http://dx.doi.org/10.1890/0012-9658(2006)87[3140:NSISE]2.0.CO;2en
dc.identifier.doihttps://doi.org/10.1890/0012-9658(2006)87[3140:nsise]2.0.co;2en
dc.identifier.issn0012-9658en
dc.identifier.urihttp://hdl.handle.net/10919/46818en
dc.identifier.urlhttp://www.esajournals.org/doi/pdf/10.1890/0012-9658%282006%2987%5B3140%3ANSISE%5D2.0.CO%3B2en
dc.language.isoen_USen
dc.publisherEcological Society of Americaen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectMichaelis-Mentenen
dc.subjectnitrateen
dc.subjectnitrogen spiralingen
dc.subjectnitrogen uptakeen
dc.subjectsaturationen
dc.subjectstable isotopeen
dc.subjectstreamsen
dc.subjecttransient storageen
dc.subjectforest ecosystemsen
dc.subjectmountain streamen
dc.subjectnitrate uptakeen
dc.subjectPhosphorusen
dc.subjectperiphytonen
dc.subjectexporten
dc.subjectlimitationen
dc.subjectretentionen
dc.subjectnutrientsen
dc.titleNitrogen saturation in stream ecosystemsen
dc.title.serialEcologyen
dc.typeArticle - Refereeden

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
0012-9658%282006%2987%5B3140.pdf
Size:
254.2 KB
Format:
Adobe Portable Document Format
Description:
Main article
Download

Collections

Scholarly Works, Biological Sciences