Seasonal patterns of nitrogen and phosphorus limitation in four German lakes and the predictability of limitation status from ambient nutrient concentrations
| Autor: | Sebastian Kolzau, Claudia Wiedner, Jacqueline Rücker, Jan Köhler, Andrew M. Dolman, Antje Köhler |
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| Rok vydání: | 2013 |
| Předmět: |
Chlorophyll
Chlorophyll a Ecological Metrics Nitrogen Science Biomass (Ecology) chemistry.chemical_element Marine and Aquatic Sciences Marine Biology Plant Science Biology Biostatistics Cyanobacteria Phosphorus metabolism chemistry.chemical_compound Nutrient Animal science Germany Phytoplankton Botany Limnology Nitrogen cycle Freshwater Ecology Multidisciplinary Ecology Phosphorus Chlorophyll A Ecology and Environmental Sciences Biology and Life Sciences Aquatic Environments Lakes chemistry Physical Sciences Earth Sciences Medicine Phycology Seasons Mathematics Statistics (Mathematics) Research Article Freshwater Environments |
| Zdroj: | PLoS ONE PLoS ONE, Vol 9, Iss 4, p e96065 (2014) |
| ISSN: | 1932-6203 |
| Popis: | To identify the seasonal pattern of nitrogen (N) and phosphorus (P) limitation of phytoplankton in four different lakes, biweekly experiments were conducted from the end of March to September 2011. Lake water samples were enriched with N, P or both nutrients and incubated under two different light intensities. Chlorophyll a fluorescence (Chla) was measured and a model selection procedure was used to assign bioassay outcomes to different limitation categories. N and P were both limiting at some point. For the shallow lakes there was a trend from P limitation in spring to N or light limitation later in the year, while the deep lake remained predominantly P limited. To determine the ability of in-lake N:P ratios to predict the relative strength of N vs. P limitation, three separate regression models were fit with the log-transformed ratio of Chla of the P and N treatments (Response ratio = RR) as the response variable and those of ambient total phosphorus:total nitrogen (TN:TP), dissolved inorganic nitrogen:soluble reactive phosphorus (DIN:SRP), TN:SRP and DIN:TP mass ratios as predictors. All four N:P ratios had significant positive relationships with RR, such that high N:P ratios were associated with P limitation and low N:P ratios with N limitation. The TN:TP and DIN:TP ratios performed better than the DIN:SRP and TN:SRP in terms of misclassification rate and the DIN:TP ratio had the highest R2 value. Nitrogen limitation was predictable, frequent and persistent, suggesting that nitrogen reduction could play a role in water quality management. However, there is still uncertainty about the efficacy of N restriction to control populations of N2 fixing cyanobacteria. |
| Databáze: | OpenAIRE |
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