Aufgrund von Vorbereitungen auf eine neue Version von KOPS, können kommenden Montag und Dienstag keine Publikationen eingereicht werden. (Due to preparations for a new version of KOPS, no publications can be submitted next Monday and Tuesday.)
Type of Publication: | Journal article |
URI (citable link): | http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-38404 |
Author: | Weyhenmeyer, Gesa A.; Jeppesen, Erik; Adrian, Rita; Arvola, Lauri; Blenckner, Thorsten; Jankowski, Thomas; Jennings, Eleanor; Nỡges, Peeter; Nỡges, Tiina; Straile, Dietmar |
Year of publication: | 2007 |
Published in: | Limnology and Oceanography ; 52 (2007), 4. - pp. 1346-1353. - eISSN 0024-3590 |
DOI (citable link): | https://dx.doi.org/10.4319/lo.2007.52.4.1346 |
Summary: |
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 N2 = N1e -k(t2 - t2), where N1 and N2 are NO3-N concentrations at
the beginning (t1) and the end (t2) 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 mg L21, 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. |
Subject (DDC): | 570 Biosciences, Biology |
Keywords: | nitrate-depleted, northern lakes, relative nitrate-nitogen, mean lake depth, denitrification |
Link to License: | Attribution-NonCommercial-NoDerivs 2.0 Generic |
Bibliography of Konstanz: | Yes |
WEYHENMEYER, Gesa A., Erik JEPPESEN, Rita ADRIAN, Lauri ARVOLA, Thorsten BLENCKNER, Thomas JANKOWSKI, Eleanor JENNINGS, Peeter NỠGES, Tiina NỠGES, Dietmar STRAILE, 2007. Nitrate-depleted conditions on the increase in shallow northern European lakes. In: Limnology and Oceanography. 52(4), pp. 1346-1353. eISSN 0024-3590. Available under: doi: 10.4319/lo.2007.52.4.1346
@article{Weyhenmeyer2007Nitra-7200, title={Nitrate-depleted conditions on the increase in shallow northern European lakes}, year={2007}, doi={10.4319/lo.2007.52.4.1346}, number={4}, volume={52}, journal={Limnology and Oceanography}, pages={1346--1353}, author={Weyhenmeyer, Gesa A. and Jeppesen, Erik and Adrian, Rita and Arvola, Lauri and Blenckner, Thorsten and Jankowski, Thomas and Jennings, Eleanor and Nỡges, Peeter and Nỡges, Tiina and Straile, Dietmar} }
Weyhenmeyer_etal07.pdf | 498 |