Publikationsdatum:
2001-04-09
Beschreibung:
A comparative (15)N-tracer study of nitrogen dynamics in headwater streams from biomes throughout North America demonstrates that streams exert control over nutrient exports to rivers, lakes, and estuaries. The most rapid uptake and transformation of inorganic nitrogen occurred in the smallest streams. Ammonium entering these streams was removed from the water within a few tens to hundreds of meters. Nitrate was also removed from stream water but traveled a distance 5 to 10 times as long, on average, as ammonium. Despite low ammonium concentration in stream water, nitrification rates were high, indicating that small streams are potentially important sources of atmospheric nitrous oxide. During seasons of high biological activity, the reaches of headwater streams typically export downstream less than half of the input of dissolved inorganic nitrogen from their watersheds.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Peterson, B J -- Wollheim, W M -- Mulholland, P J -- Webster, J R -- Meyer, J L -- Tank, J L -- Marti, E -- Bowden, W B -- Valett, H M -- Hershey, A E -- McDowell, W H -- Dodds, W K -- Hamilton, S K -- Gregory, S -- Morrall, D D -- New York, N.Y. -- Science. 2001 Apr 6;292(5514):86-90.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11292868" target="_blank"〉PubMed〈/a〉
Schlagwort(e):
Absorption
;
Animals
;
Bacteria/metabolism
;
Biofilms
;
*Ecosystem
;
Eukaryota/metabolism
;
*Fresh Water
;
Fungi/metabolism
;
Geologic Sediments
;
Nitrates/metabolism
;
Nitrogen/*metabolism
;
Oxidation-Reduction
;
Photosynthesis
;
Quaternary Ammonium Compounds/metabolism
;
Seasons
;
United States
Print ISSN:
0036-8075
Digitale ISSN:
1095-9203
Thema:
Biologie
,
Chemie und Pharmazie
,
Informatik
,
Medizin
,
Allgemeine Naturwissenschaft
,
Physik
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