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Nitrate-depleted conditions on the increase in shallow northern European lakes

Weyhenmeyer, Gesa and Jeppesen, Erik and Adrian, Rita and Arvola, Lauri and Blenckner, Thorsten and Jankowski, Thomas and Jennings, Eleanor and Noges, Peeter and Noges, Tiina and Straile, Dietmar (2007). Nitrate-depleted conditions on the increase in shallow northern European lakes. Limnology and Oceanography. 52:4, 1346-1353
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Official URL: http://dx.doi.org/10.4319/lo.2007.52.4.1346

Abstract

We determined relative nitrate-nitrogen (NO3- N) loss rates in 100 north-mid-European lakes from late spring to summer by using the exponential function N-2 5 N-1e(-k)( (t)(2) - (t)(2)), where N-1 and N-2 are NO3- N concentrations at the beginning (t(1)) and the end (t(2)) of the time interval, respectively, and k is the specific NO3- N loss rate. We found that k decreased with increasing lake depth. Adjusting k to the lake depth (k(adj)), we observed that k(adj) was positively related to spring NO3-N concentrations, but this relationship became insignificant at mean lake depths exceeding 12.5 m. A relationship between k(adj) and spring NO3- N concentrations in lakes shallower than 12.5 m implies that changes in spring NO3-N concentrations influence the NO3- N loss rate and thereby summer NO3- N concentrations. Time series from one Estonian, one German, and 14 Swedish lakes shallower than 12.5 m since 1988 revealed that May to August NO3-N concentrations have decreased over time everywhere, and the number of time periods exhibiting a NO3-N depleted condition, i.e., NO3-N levels below 10 mu g L-1, in these lakes has tripled since 1988. We explained the decreasing NO3-N concentrations by a reduction in external nitrogen loading including atmospheric deposition, and by changes in climate. The observed prolongation of NO3- N depleted conditions might be one possible explanation for the increasing occurrence of nitrogen- fixing cyanobacteria in a variety of lake ecosystems.

Authors/Creators:Weyhenmeyer, Gesa and Jeppesen, Erik and Adrian, Rita and Arvola, Lauri and Blenckner, Thorsten and Jankowski, Thomas and Jennings, Eleanor and Noges, Peeter and Noges, Tiina and Straile, Dietmar
Title:Nitrate-depleted conditions on the increase in shallow northern European lakes
Series/Journal:Limnology and Oceanography (0024-3590)
Year of publishing :2007
Depositing date:2015
Volume:52
Number:4
Page range:1346-1353
Number of Pages:8
Place of Publication:WACO
Publisher:Association for the Sciences of Limnology and Oceanography (ASLO)
ISSN:0024-3590
Language:English
Publication Type:Journal article
Refereed:Yes
Article category:Scientific peer reviewed
Version:Published version
Full Text Status:Public
Agris subject categories.:M Aquatic sciences and fisheries > M40 Aquatic ecology
P Natural resources > P10 Water resources and management
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 405 Other Agricultural Sciences > Environmental Sciences related to Agriculture and Land-use
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Fish and Aquacultural Science
Agrovoc terms:lakes, nitrogen, Europe, ecosystems, environment
Keywords:lakes, nitrogen, Europe, lake ecosystems, depleted conditions, environment
URN:NBN:urn:nbn:se:slu:epsilon-e-2761
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2761
Additional ID:
Type of IDID
Web of Science (WoS)000248215800006
ID Code:12093
Faculty:NL - Faculty of Natural Resources and Agricultural Sciences (until 2013)
Department:(NL, NJ) > Dept. of Environmental Assessment
Deposited By: SLUpub Connector
Deposited On:30 Jun 2015 09:47
Metadata Last Modified:09 Feb 2016 10:40

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