Unifying Nutrient–Chlorophyll Relationships in Lakes

1989 ◽  
Vol 46 (7) ◽  
pp. 1176-1182 ◽  
Author(s):  
Yves T. Prairie ◽  
Carlos M. Duarte ◽  
Jacob Kalff

We used data drawn from the literature to test some basic predictions derived from nutrient limitation theory. Contrary to expectation, nitrogen was not better correlated to chlorophyll in nitrogen limited lakes (as measured by the total nitrogen:total phosphorus (TN:TP) ratio). We also examined whether the variability in published relationships between chlorophyll a (Chla) and nutrient levels in lakes can be explained by differences in the relative concentrations of nitrogen and phosphorus (TN:TP ratio). Our results show that the coefficients and precision of the Chla = f(TP) and Chla = f(TN) regression equations vary systematically and concomitantly with TN:TP ratios, and are highest for lakes with TN:TP ratios of 23–28 (by weight). These findings were confirmed with independent data and explain the variability of published Chla = f(TP) relationships. We propose a model that predicts the coefficients of Chla = f(TP) and Chla = f(TN) equations for lakes with different TN:TP ratios. This model proved useful in predicting the chlorophyll trajectories of lakes over time. The results imply an "optimal" TN:TP ratio beyond which the relative rates of increase in chlorophyll with increasing nutrient concentrations are reduced.

1984 ◽  
Vol 14 (6) ◽  
pp. 794-802 ◽  
Author(s):  
Ralph E. J. Boerner

To determine how soil nutrient availability influences nutrient cycling, fluxes of nutrients through litterfall and decomposition were determined for four forest stands similar in all respects except soil nutrient availability and microclimate, within Neotoma Valley, a small watershed in southern Ohio, U.S.A. Litterfall varied from 10 to 60% among sites while nutrient concentrations and masses in new leaf litter varied as a function of extractable soil nutrient levels. Mass loss from litterbags was significantly higher in more fertile sites. Stepwise regression indicated that initial litter nitrogen and phosphorus concentrations were strongly correlated with relative decomposition rate while lignin concentration and microclimate variables were only correlated weakly. Thus, both litterfall nutrient transfers and decomposition rates were under the control of soil nutrient levels. Nitrogen was immobilized in litter at all sites during the 1st year of decay; litter from more fertile sites mineralized nitrogen during the 2nd year, while that from less fertile sites continued to immobilize nitrogen. Phosphorus and calcium mineralization rates were strongly correlated with the availability of these elements in the soil. Magnesium and potassium were leached rapidly from litter; amounts mineralized were correlated with amounts in litterfall. Interrelations among soil fertility, litterfall, and nutrient mineralization, as well as litter redistribution, are discussed as processes important in the development and maintenance of the soil fertility gradient in this watershed.


Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Willem H. van de Poll ◽  
Gemma Kulk ◽  
Patrick D. Rozema ◽  
Corina P. D. Brussaard ◽  
Ronald J. W. Visser ◽  
...  

Glacial meltwater discharge in fjords on the west coast of Spitsbergen is increasing due to climate change. The influence of this discharge on phytoplankton nutrient limitation, composition, productivity and photophysiology was investigated in central (M) and inner (G) Kongsfjorden (79°N, 11°40’E). Freshwater influx intensified stratification during June 2015, coinciding with surface nutrient depletion. Surface nutrient concentrations were negatively correlated with stratification strength at station M. Here, nitrate addition assays revealed increasing N limitation of surface phytoplankton during the second half of June, which was followed by a pronounced compositional change within the flagellate-dominated phytoplankton community as dictyochophytes (85% of chl a) were replaced with smaller haptophytes (up to 60% of chlorophyll a) and prasinophytes (20% of chlorophyll a). These changes were less pronounced at station G, where surface phosphate, ammonium and nitrate concentrations were occasionally higher, and correlated with wind direction, suggesting wind-mediated transport of nutrient-enriched waters to this inner location. Therefore, glacial meltwater discharge mediated nutrient enrichment in the inner fjord, and enhanced stratification in inner and central Kongsfjorden. Surface chlorophyll a and water column productivity showed 3–4-fold variability, and did not correlate with nutrient limitation, euphotic zone depth, or changed taxonomic composition. However, the maximum carbon fixation rate and photosynthetic efficiency showed weak positive correlations to prasinophyte, cryptophyte, and haptophyte chlorophyll a. The present study documented relationships between stratification, N limitation, and changed phytoplankton composition, but surface chlorophyll a concentration, phytoplankton photosynthetic characteristics, and water column productivity in Kongsfjorden appeared to be driven by mechanisms other than N limitation.


2020 ◽  
Author(s):  
Mateus Dantas de Paula ◽  
Thomas Hickler

<p>The HUMBOLDT-LSM<sub>bio</sub> component is an expansion of the LPJ-GUESS dynamic vegetation model , including local diversity of plant traits and an organic matter module representing the Nitrogen and Phosphorus cycles. In the new trait variation module the initial full range of possible traits is filtered along the altitudinal gradient with the aim to predict the trait distribution of communities observed in the field. The model was parameterized using local trait data per species collected by field campaigns along the whole altitudinal gradient, considering the leaf and wood economics spectrum and tissue nutrient concentrations, and locally measured N and P flux data, in which we were able to use deposition and weathering rates, as well as soil organic and mineral layer nutrient concentrations. In order to evaluate the model with regards to nutrient limitation, the simulation experiment was designed with the NUMEX nutrient manipulation experiment in mind, meaning that the reference nutrient limited community was compared to simulations in which N or/and P limitations were deactivated (i.e. plants could grow independent of their N or P demands being met). Results in NUMEX suggested that the removal of nutrient limitation would produce more biotically homogenous communites, and taller trees with higher productivity and more allocation to belowground biomass.</p><p>Our results indicate that including trait diversity and nutrient limitation provide a significant improvement in relation to ecosystem representation especially at higher elevations. Deactivation of nutrient limitation suggests reduced community trait differentiation along the elevation gradient (e.g. specific leaf area), and increased productivity (i.e. Carbon and NPP values). Deactivation of trait diversity impels plant survival at higher altitudes. Significant model improvements are expected in the future with further field trait measurements from the RESPECT subprojects, and the inclusion of other significant processes such as leaf herbivory, seed dispersal and of course the coupled model runs with LSM<sub>atmo</sub> and LSM<sub>hydro</sub>.</p>


2010 ◽  
Vol 67 (4) ◽  
pp. 743-753 ◽  
Author(s):  
Philippe Souchu ◽  
Béatrice Bec ◽  
Val H. Smith ◽  
Thierry Laugier ◽  
Annie Fiandrino ◽  
...  

A cross-ecosystem comparison of data obtained from 20 French Mediterranean lagoons with contrasting eutrophication status provided the basis for investigating the variables that best predict chlorophyll a (Chl a) concentrations and nutrient limitation of phytoplankton biomass along a strong nutrient enrichment gradient. Summer concentrations of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) comprised only a small fraction of total nitrogen (TN) and total phosphorus (TP). On the basis of inorganic nutrient concentrations, the most oligotrophic lagoons appeared to be phosphorus-limited, with a tendency towards the development of nitrogen limitation as eutrophication increased, as evidenced by decreasing DIN:DIP ratios. A weak but significantly positive relationship was found between dissolved silicate (DSi) and Chl a, reflecting DSi accumulation in the water column along the trophic state gradient and implying a progressive shift away from potential Si limitation of phytoplankton growth. Observed concentrations of Chl a were far better explained by TN and TP than by DIN and DIP concentrations, suggesting that a total nutrient based approach is likely to be the most appropriate for managing eutrophication in Mediterranean lagoons and other coastal waters. These results give credence to the idea that marine and freshwater environments respond in a similar fashion to nutrient enrichment.


2021 ◽  
Vol 21 (2) ◽  
pp. 81-88
Author(s):  
Anna Płachta

Abstract A study was carried out on Lake Mielenko in Kartuzy. It is a small and shallow waterbody (7.8 ha, max. depth 1.8 m), whose morphometric conditions qualify it as a polymictic lake (the first lake in a river - lake system). Before the reclamation began, the lake was characterized by a high concentration of chlorophyll-a (16.4 mg m−3 in spring to 33 mg m−3 in summer) and low visibility. The purpose of the study was to determine the impact of the first stage of restoration of Lake Mielenko by phosphorus inactivation using a combination of aluminum and iron coagulants (PIX and PAX). After coagulant dosing into the lake, a significant decrease in chlorophyll-a was observed, which resulted in improving water transparency in the lake and decreasing concentrations of both nutrients (nitrogen and phosphorus). The total concentration of nutrients was dominated by organic forms (constituting 71-95%). Maximum nutrient concentrations were 0.273±0.01 mg P L−1 and 5.52±0.1 mg N L-1 (in the summer period before the restoration activities were performed).


Oikos ◽  
2014 ◽  
Vol 124 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Matthew E. S. Bracken ◽  
Helmut Hillebrand ◽  
Elizabeth T. Borer ◽  
Eric W. Seabloom ◽  
Just Cebrian ◽  
...  

1990 ◽  
Vol 47 (7) ◽  
pp. 1348-1355 ◽  
Author(s):  
Ralph E. H. Smith ◽  
W. Glen Harrison ◽  
Leslie R. Harris ◽  
Alex W. Herman

The vertical fine structure of particulate matter and inorganic nutrients through the bottom layers of sea ice was determined at a site in the Canadian high arctic. Intense vertical gradients of chlorophyll a, nitrate, ammonium, nitrite, phosphate, and silicate developed in the lower 6 cm of the ice as ice algae attained standing crops of 250 mg∙m−2 (up to 60 mg∙L−1) of chlorophyll a. Pigment and inorganic nutrient concentrations were closely correlated, and pools of inorganic nutrient were shown to exist in the particulate matter, suggesting that the extremely high dissolved nutrient concentrations in the bottom ice (e.g. up to 400 μmol∙L−1 nitrate) were derived at least in part from leakage of algal intracellular pools. Nitrogen and phosphorus were present in excess of algal needs, but silicon may not have been. The ratios of particulate organic carbon to chlorophyll a and to particulate organic nitrogen increased from the ice–water interface upwards, consistent with a physiological response of the ice algae to the strong corresponding gradient of light availability. Although spatially compact, the assemblage of algae in the bottom ice inhabits a highly stratified environment.


2005 ◽  
Vol 40 (4) ◽  
pp. 418-430 ◽  
Author(s):  
Markus L. Heinrichs ◽  
Brian F. Cumming ◽  
Kathleen R. Laird ◽  
J. Sanford Hart

Abstract Diatom and chironomid analysis of sediments encompassing the past 400 years from Bouchie Lake, British Columbia, suggests two distinct periods of limnological conditions. Prior to 1950 AD, Fragilaria construens and F. pinnata are the most common diatom species, and Chironomus, Procladius and Tanytarsini dominate the chironomid record. Moderately low nutrient concentrations consistent with oligo-mesotrophic lakes are inferred. From 1950, the diatom assemblage is dominated by Stephanodiscus parvus, a eutrophic indicator, whereas the chironomid communities show a relative increase in littoral taxa coincident with lower head capsule abundance. Higher nutrient levels, specifically total phosphorus, which increased from 8 µg L-1 prior to 1950 to 20 µg L-1 currently, are coincident with midge communities indicative of lower oxygen concentrations. Observed biotic changes and nutrient levels inferred from the sediment core correspond to historical land-use changes.


Author(s):  
Néstor David Giraldo ◽  
Sandra Marcela Correa ◽  
Andrés Arbeláez ◽  
Felix L. Figueroa ◽  
Rigoberto Ríos-Estepa ◽  
...  

AbstractIn this study the metabolic responses of Botryococcus braunii were analyzed upon different inorganic carbon dosages and nutrient limitation conditions in terms of lipid and biomass productivity, as well as photosynthetic performance. The nutritional schemes evaluated included different levels of sodium bicarbonate and nitrogen and phosphorus starvation, which were contrasted against standard cultures fed with CO2. Bicarbonate was found to be an advantageous carbon source since high dosages caused a significant increase in biomass and lipid productivity, in addition to an enhanced photosynthetic quantum yield and neutral lipids abundance. This contrasts to the commonly used approach of microalgae nutrient limitation, which leads to high lipid accumulation at the expense of impaired cellular growth, causing a decline in overall lipid productivity. The lipidome analysis served to hypothesize about the influence of the nutritional context on B. braunii structural and storage lipid metabolism, besides the adaptive responses exhibited by cells that underwent nutrient stress.


Author(s):  
Yuequn Lai ◽  
Jing Zhang ◽  
Yongyu Song ◽  
Zhaoning Gong

Remote sensing retrieval is an important technology for studying water eutrophication. In this study, Guanting Reservoir with the main water supply function of Beijing was selected as the research object. Based on the measured data in 2016, 2017, and 2019, and Landsat-8 remote sensing images, the concentration and distribution of chlorophyll-a in the Guanting Reservoir were inversed. We analyzed the changes in chlorophyll-a concentration of the reservoir in Beijing and the reasons and effects. Although the concentration of chlorophyll-a in the Guanting Reservoir decreased gradually, it may still increase. The amount and stability of water storage, chlorophyll-a concentration of the supply water, and nitrogen and phosphorus concentration change are important factors affecting the chlorophyll-a concentration of the reservoir. We also found a strong correlation between the pixel values of adjacent reservoirs in the same image, so the chlorophyll-a estimation model can be applied to each other.


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