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
[Research article]
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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 | ||||
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Title: | Nitrate-depleted conditions on the increase in shallow northern European lakes | ||||
Series Name/Journal: | Limnology and Oceanography | ||||
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: | Research 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: |
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ID Code: | 12093 | ||||
Faculty: | NL - Faculty of Natural Resources and Agricultural Sciences (until 2013) | ||||
Department: | (NL, NJ) > Dept. of Environmental Assessment (until 080831) | ||||
Deposited By: | SLUpub Connector | ||||
Deposited On: | 30 Jun 2015 09:47 | ||||
Metadata Last Modified: | 09 Sep 2020 14:17 |
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