Empirical Models for Zoobenthic Biomass in Lakes

1987 ◽  
Vol 44 (5) ◽  
pp. 990-1001 ◽  
Author(s):  
Joseph B. Rasmussen ◽  
Jacob Kalff
Keyword(s):  
Littoral Zone ◽  
Chlorophyll Concentration ◽  
Empirical Models ◽  
Phosphorus Concentration ◽  
Lake Area ◽  
Total Phosphorus Concentration ◽  
Secchi Disk Transparency ◽  
Littoral Zones ◽  
Explained Variance ◽  
Local Variability

Estimates of macrozoobenthos from the literature were regressed against a series of limnological variables to yield empirical models for zoobenthic biomass in the profundal, sublittoral, and littoral zones of lakes. Variables indicative of phytoplankton biomass (chlorophyll concentration, total phosphorus concentration, and Secchi disk transparency) explained between 14 and 57% of the variance of zoobenthic biomass ((g/m2)0.1). Other factors such as humic colour, morphometry (slope, mean depth, ratio of mean to maximum depth, and lake area), and mean annual air temperature substantially increased the amount of explained variance. In the profundal and sublittoral zones, the best models explain 70% of the variance in zoobenthic biomass. Littoral zone models explained less than 50%, and this deficiency was attributed to sampling difficulties and to high local variability of slope and wave exposure in the littoral zone.

Forest fire induced impacts on phosphorus, nitrogen, and chlorophyll a concentrations in boreal subarctic lakes of northern Alberta

2000 ◽  
Vol 57 (S2) ◽  
pp. 73-81 ◽  
Author(s):  
P McEachern ◽  
E E Prepas ◽  
J J Gibson ◽  
W P Dinsmore
Keyword(s):  
Total Phosphorus ◽  
Forest Fire ◽  
Chlorophyll Concentration ◽  
Soluble Reactive Phosphorus ◽  
Phosphorus Concentration ◽  
Subarctic Lakes ◽  
Total Phosphorus Concentration ◽  
Subarctic Region ◽  
Total Dissolved Nitrogen ◽  
Northern Alberta

The biogeochemistry of 10 headwater lakes in burnt peatland-conifer catchments and 14 in unburnt catchments was evaluated throughout a summer 2 years following forest fire in a boreal subarctic region of northern Alberta. Cation exchange within burnt catchments resulted in proton flux and a 9% reduction in mean pH. Lakes in burnt catchments contained more than twofold higher (P << 0.01) mean concentrations of total, total dissolved, and soluble reactive phosphorus, 1.5-fold higher (P << 0.01) concentrations of dissolved organic carbon, and more than 1.2-fold higher (P < 0.05) concentrations of total and total dissolved nitrogen, nitrate + nitrite, and ammonium compared with reference lakes. Total phosphorus concentration explained 86% of the variance in reference lake chlorophyll concentration but was not related to chlorophyll concentration in burnt lakes. Analysis of chlorophyll - total phosphorus residuals suggested that algae in burn-impacted lakes were light limited. With the addition of five lakes burnt between 1961 and 1985, time since disturbance and percent disturbance combined explained 74% of the variance in total phosphorus among burnt lakes. Fire caused increased flux of materials to the study lakes with slow recovery over decades.

Relationship of Salmonine Production to Lake Trophic Status and Temperature

1993 ◽  
Vol 50 (6) ◽  
pp. 1324-1328 ◽  
Author(s):  
Céline Plante ◽  
John A. Downing
Keyword(s):  
Trophic Status ◽  
Phosphorus Concentration ◽  
Lake Area ◽  
Eutrophic Lakes ◽  
Total Phosphorus Concentration ◽  
Phytoplankton Productivity ◽  
The North ◽  
Air Temperatures ◽  
Statistical Effect ◽  
Relationship Of

Data on trout, char, and salmon from lakes in several geographic areas indicate that salmonine production (P, kilograms per hectare per year) increases with total phosphorus concentration (TP, micrograms per litre) as log10P = 0.47 + 0.95 log10TP (r2 = 0.61). A positive relationship was also found between P and phytoplankton productivity and this relationship suggests that energy transfer efficiencies from phytoplankton to salmonines are reduced in eutrophic lakes. Lake area and mean depth had no significant statistical effect on P but salmonine production was significantly lower in warmer climates. Analysis of these data suggests that projected global increases in air temperatures could lead to about 50% reductions in salmonine production and yield in the north temperate zone.

Low-Nitrate-Days (LND), a Potential Indicator of Cyanobacteria Blooms in a Eutrophic Hardwater Reservoir

2007 ◽  
Vol 42 (4) ◽  
pp. 269-283 ◽  
Author(s):  
Gertrud K. Nürnberg
Keyword(s):  
Water Quality ◽  
Low Flow ◽  
Phosphorus Concentration ◽  
Climatic Index ◽  
Catchment Basin ◽  
Total Phosphorus Concentration ◽  
Secchi Disk Transparency ◽  
Natural Lakes ◽  
Cyanobacteria Blooms ◽  
Thames River

Abstract When nitrate was low in a hypereutrophic, hardwater reservoir, cyanobacteria proliferated into blooms. Based on this observation an index was developed that relates an easily measurable variable, the period of Low-Nitrate-Days (LND), to the period when nuisance cyanobacteria (blue-greens) proliferate and “bloom”. The bloom indicator LND (d·yr-1) was defined as the period of time during summer and early fall when nitrate concentration is below a lake-specific threshold. This concept was valuable in Fanshawe Lake, a southern Ontario reservoir of the Thames River in the Lake Erie catchment basin, where traditional bloom indicators are rare. A nitrate threshold of 1 to 2 mg·L-1 is supported by occasional observations of chlorophyll (Chl) concentration, blue-green biomass, visual inspection, and photographic documentation. Fanshawe Lake's water quality (phosphorus, Chl, and Secchi disk transparency) varied from summer to summer and LND ranged from 0 to 175 d·yr-1 with a long-term average of 62 d·yr-1 for 38 years. LND was positively and significantly correlated with average summer total phosphorus concentration (available for 8 years), but not Chl (n = 6) nor transparency (n = 11), possibly because of an invasion by the zebra mussel Dreissena. LND values agreed well with cyanobacteria biomass indicators predicted from other models. Significant relationships with 38 years of flows and the climatic index (winter North Atlantic Oscillation) reveal that during high-flow years estimated cyanobacteria blooms are infrequent, while during low-flow years bloom periods are extended and the water quality is poor. Investigations on other man-made lakes and river sections of the Thames River, and preliminary studies on natural lakes with differing trophic states show that LND may be a useful variable in all lakes and reservoirs where nutrient limitation switches from phosphorus to nitrogen during summer.

Empirical Relationships of Phytomacrofaunal Abundance to Plant Biomass and Macrophyte Bed Characteristics

1988 ◽  
Vol 45 (6) ◽  
pp. 976-984 ◽  
Author(s):  
Hélène Cyr ◽  
John A. Downing
Keyword(s):  
Organic Matter ◽  
Total Phosphorus ◽  
Plant Biomass ◽  
Organic Matter Content ◽  
Matter Content ◽  
Rooting Depth ◽  
Phosphorus Concentration ◽  
Regression Equations ◽  
Lake Area ◽  
Total Phosphorus Concentration

The abundance of phytophilous invertebrates was measured in 13 macrophyte beds and was related, using multiple regression analysis, to the biomass of macrophytes among which the invertebrates were collected, the average plant biomass growing per unit lake area, water and organic matter content of the sediments, total phosphorus concentration in the water, rooting depth of the macrophyte bed, and sampling date. Quantitative analyses are presented for chironomids, cladocerans, cyclopoid copepods, gastropods, water mites (Hydracarina), ostracods, and trichopterans. R2 values for the regression equations ranged from 0.43 to 0.81. The abundance of invertebrates was best related to the biomass of separate plant species, but equations based only on total plant biomass sometimes had equivalent R2 values, in general, the abundance of phytophilous invertebrates was positively related to areal plant biomass, sediment organic matter, and lake trophic status and negatively related to depth. The abundance of phytophilous invertebrates generally rose throughout the sampling season. The sign of the relationship with sediment water content, however, varied among invertebrate taxa. Macrophyte beds with high areal plant biomass, in lakes with high total phosphorus concentration, support the greatest abundance of potential invertebrate food for fish and waterfowl.

Nutrient, chlorophyll, and water clarity relationships in Florida's nearshore coastal waters with comparisons to freshwater lakes

2002 ◽  
Vol 59 (6) ◽  
pp. 1024-1031 ◽  
Author(s):  
Mark V Hoyer ◽  
Thomas K Frazer ◽  
Sky K Notestein ◽  
Daniel E Canfield, Jr.
Keyword(s):  
Coastal Waters ◽  
Chlorophyll Concentration ◽  
Secchi Depth ◽  
Dominant Factor ◽  
Phosphorus Concentration ◽  
Limiting Factor ◽  
Freshwater Lakes ◽  
Total Phosphorus Concentration ◽  
Marine Systems ◽  
Freshwater Systems

Models relating chlorophyll to nutrients and Secchi depth to chlorophyll using data from nearshore coastal waters of Florida were successfully developed. The models suggest that phosphorus is the primary limiting factor for phytoplankton in the nearshore coastal waters of Florida and that total phosphorus concentration accounts for 81% of the variance in chlorophyll concentration. The models also show that chlorophyll is the dominant factor determining Secchi depth in nearshore coastal waters of Florida and that chlorophyll concentrations account for 68% of the variance in Secchi depth. Thus, these models are robust and should be useful for eutrophication management of Florida's coastal marine systems. The models developed with data from nearshore coastal waters of Florida are similar to models developed for freshwater lakes in Florida, but the amount of chlorophyll per unit of phosphorus and Secchi depth per unit of chlorophyll are both significantly less for marine samples. This suggests that the chlorophyll to biovolume ratios in the nearshore coastal waters of Florida are less than in freshwater systems of Florida. Therefore, nutrient to chlorophyll and chlorophyll to Secchi depth models developed for freshwater systems are probably ill suited for use in Florida's marine systems.

Chlorophyll-total phosphorus relationships in Lake Burragorang, New South Wales, and some other Southern Hemisphere lakes

1985 ◽  
Vol 36 (2) ◽  
pp. 157 ◽  
Author(s):  
JM Ferris ◽  
PA Tyler
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Total Phosphorus ◽  
Chlorophyll Concentration ◽  
Predictor Variable ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
Annual Maximum ◽  
Total Phosphorus Concentration ◽  
Turbid Waters

Linear regression of chlorophyll concentration on total phosphorus concentration for phosphorus- limited Lake Burragorang, N.S.W., yields regression coefficients within the range reported for individual lakes in the Northern Hemisphere. Some variation in slope of published regressions is attributable to the choice of different regression subvariables (e.g. annual mean or annual maximum). The extent of this variation is quantified. Data from Lake Burragorang and other sites indicate that chlorophyll-phosphorus relationships in the Southern Hemisphere are concordant with those in the north if turbid waters are excluded from consideration. This is obviously significant in Australia, with so many turbid waters. The notion of 'growing season', as applied to Northern Hemisphere studies, is inappropriate for the warm temperate conditions of Lake Burragorang, and it was necessary instead to use the annual maximum chlorophyll concentration. Prediction of annual maximum chlorophyll concentration is of particular significance to water-quality management. Despite highly significant regressions, 95% confidence intervals and 95% prediction limits are wide, so that prediction of chlorophyll concentration from single values of total phosphorus, using double-In regressions, gives a wide arithmetic range. Use of annual mean total phosphorus concentration as the predictor variable limits the forecasting ability of the Lake Burragorang regressions but facilitates future coupling with a phosphorus loading model. This would assist in the assessment of projected management plans and the formulation of protective loading criteria.

Response of summer chlorophyll concentration to reduced total phosphorus concentration in the Rhine River (Netherlands) and the Sacramento – San Joaquin Delta (California, USA)

2007 ◽  
Vol 64 (11) ◽  
pp. 1529-1542 ◽  
Author(s):  
Erwin E Van Nieuwenhuyse
Keyword(s):  
Total Phosphorus ◽  
Nitrogen Concentration ◽  
Chlorophyll Concentration ◽  
Water Systems ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
Flowing Water ◽  
Rhine River ◽  
Total Phosphorus Concentration ◽  
Fold Reduction

Reductions in wastewater loading led to significant declines in mean summer total phosphorus (TP) and chlorophyll concentration (Chl) in two large flowing water systems despite their initially shallow (<2 m) euphotic depth and continually high (>40 mg·m-3) soluble reactive P concentration. In the Rhine River, a gradual 2.7-fold reduction in TP resulted in a 4-fold decline in Chl. In the Sacramento – San Joaquin Delta, an abrupt 1.5-fold reduction in TP led to an equally abrupt 2.6-fold reduction in Chl. Neither response could be attributed to coincidental changes in flow, light, or nitrogen concentration. The slope of the response (Chl:TP) in both systems paralleled the average trajectory calculated using an among-system TP–Chl relationship for a broad cross section of flowing waters. The results suggest that TP was the principal determinant of Chl in both systems and that control of phosphorus loading may be an effective tool for managing eutrophication in other flowing water systems with relatively high (10–100 mg·m-3) soluble reactive P concentrations.

Lake Paranoá, Brasília, Brazil: Integrated Management Plan for its Restoration

1992 ◽  
Vol 27 (2) ◽  
pp. 271-286 ◽  
Author(s):  
Sonia Paulino Mattos ◽  
Irene Guimarães Altafin ◽  
Hélio José de Freitas ◽  
Cristine Gobbato Brandão Cavalcanti ◽  
Vera Regina Estuqui Alves
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Integrated Management ◽  
Algal Growth ◽  
Nutrient Content ◽  
Management Plan ◽  
Cylindrospermopsis Raciborskii ◽  
Phosphorus Concentration ◽  
Limiting Factor ◽  
Total Phosphorus Concentration

Abstract Built in 1959, Lake Paranoá, in Brasilia, Brazil, has been undergoing an accelerated process of nutrient enrichment, due to inputs of inadequately treated raw sewage, generated by a population of 600,000 inhabitants. Consequently, it shows high nutrient content (40 µg/L of total phosphorus and 1800 µg/L of total nitrogen), low transparency (0.65 m) and high levels of chlorophyll a (65 µg/L), represented mainly by Cylindrospermopsis raciborskii and sporadic bloom of Microcystis aeruginosa, which is being combatted with copper sulphate. With the absence of seasonality and a vertical distribution which is not very evident, the horizontal pattern assumes great importance in this reservoir, in which five compartments stand out. Based on this segmentation and on the identification of the total phosphorus parameter as the limiting factor for algal growth, mathematical models were developed which demonstrate the need for advanced treatment of all the sewage produced in its drainage basin. With this, it is expected that a process of restoration will be initiated, with a decline in total phosphorus concentration to readings below 25 µg/L. Additional measures are proposed to accelerate this process.

scholarly journals Phytase-Producing Rahnella aquatilis JZ-GX1 Promotes Seed Germination and Growth in Corn (Zea mays L.)

2021 ◽  
Vol 9 (8) ◽  
pp. 1647
Author(s):  
Gui-E Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Shi-Bo Ma
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Biomass Accumulation ◽  
Root Surface ◽  
Phosphorus Concentration ◽  
Maize Seedlings ◽  
Total Phosphorus Concentration ◽  
Rahnella Aquatilis ◽  
Maize Seeds

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1，the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.

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