Patterns in the Submerged Macrophyte Biomass of Lakes and the Importance of the Scale of Analysis in the Interpretation

1990 ◽  
Vol 47 (2) ◽  
pp. 357-363 ◽  
Author(s):  
Carlos M. Duarte ◽  
Jacob Kalff
Keyword(s):  
Plant Biomass ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Site Specific ◽  
Light Levels ◽  
Threshold Phenomena ◽  
Site Characteristics ◽  
Specific Biomass ◽  
Regulation Mechanisms ◽  
Lake Characteristics

The relative contributions of lake characteristics (i.e. alkalinity, chlorophyll A concentration, total phosphorus concentration, conductivity, and morphometry) and site characteristics (i.e. depth, littoral slope, exposure to waves, and underwater light levels) to the variability in submerged biomass were examined in 25 Canadian and American lakes. Lake-average submerged biomass is a function of water alkalinity and the lake-average littoral slope whereas site-specific biomass is a function of both site and lake characteristics. Plant biomass decreased with increasing slope and wave exposure and increased with increasing alkalinity and light levels. However, these relationships are complex because submerged biomass is also influenced by threshold phenomena (e.g. critical littoral slopes and transparency-dependent critical depths) that set limits to macrophyte colonization and because the relative contributions of the most relevant environmental factors studied (i.e. littoral slope, exposure, water transparency, and alkalinity) are depth dependent. By demonstrating the importance of lake-average and site-specific scales of variation and the existence of noncontinuous (e.g. threshold) regulation mechanisms the findings provide a new conceptual framework for the study of the relationship between submerged macrophytes, and their associated biota as well as their environment.

Reconstructing past lake water total phosphorus concentration using sediment geochemical records

2020 ◽  
Author(s):  
Madeleine Moyle ◽  
John Boyle ◽  
Richard Chiverrell
Keyword(s):  
Lake Sediment ◽  
Lake Water ◽  
Critical Evaluation ◽  
Future Climate Change ◽  
Phosphorus Concentration ◽  
General Applicability ◽  
Total Phosphorus Concentration ◽  
Site Specific ◽  
Geochemical Method ◽  
P Cycle

<p>To understand current phosphorus (P) cycling, which encompasses disturbances caused by human activity, it is necessary to quantify the long-term natural P cycles on which modern drivers act. The shortness of monitored P records renders this difficult by only covering the post-disturbance period and therefore fail to capture pre-disturbance baselines. Target driven management of sensitive ecosystems suffering from eutrophication uses baselines for P that cannot be reliably quantified at present. Recovery will only be possible if P loadings can be brought under control and this requires an understanding of what water quality targets are both desirable and achievable on a site-specific basis. This matters because a well-functioning ecosystem will be more resilient under future climate change and increasing human pressure on the landscape.</p><p>Where lakes are present in the landscape, there is the opportunity to use the sediment archive to provide long records of past P concentration.  At present, these reconstructions rely on diatoms or related microfossil indicators. These require time and resource intensive tailored training sets and furthermore the records do not preserve in all lakes. Here we present a novel geochemical method for reconstructing water P concentrations based on lake sediment P burial fluxes, which in principle is universally applicable.</p><p>Tested at six published lake sites, the method produces results that agree very well with overlapping monitoring data for those lakes (r<sup>2 </sup>= 0.8). We want to share our method with the research community to identify additional sites to further verify the general applicability.</p><p>To illustrate the value of this approach to site-specific management, we compare past lake water total P reconstructions at Crosemere (UK) with a record of Holocene land cover change to identify the drivers of acceleration in the P cycle. Wider application of this lake sediment geochemical method will allow more critical evaluation of the human and natural drivers of the P cycle and be of benefit to ‘systems understanding’ spanning terrestrial and aquatic ecosystems.</p>

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.

Wild oat and barley interactions: varietal differences in competitiveness in relation to phosphorus supply

1989 ◽  
Vol 67 (11) ◽  
pp. 3366-3371 ◽  
Author(s):  
D. W. Konesky ◽  
M. Y. Siddiqi ◽  
A. D. M. Glass ◽  
A. I. Hsiao
Keyword(s):  
Plant Biomass ◽  
Sand Culture ◽  
Phosphorus Concentration ◽  
Wild Oat ◽  
Herbicide Application ◽  
Hordeum Vulgare L ◽  
Total Phosphorus Concentration ◽  
Barley Cultivars ◽  
Selection Of ◽  
Phosphorus Levels

Nine cultivars of barley (Hordeum vulgare L.) were separately planted with wild oat (Avena fatua L.) in sand culture at two external phosphorus concentrations. Barley cultivars differed substantially in their ability to compete with wild oat. Relative competitive abilities of the barley cultivars were strongly influenced by external phosphorus levels. The greatest effect of competition, particularly at low external phosphorus, was upon plant biomass rather than on internal total phosphorus concentration. The selection of cultivars that are able to compete effectively with wild oat may represent an alternative (biological) strategy to the traditional one of herbicide application.

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.

scholarly journals Efficiency of Recycled Biogas Digestates as Phosphorus Fertilizers for Maize

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 553
Author(s):  
Inga-Mareike Bach ◽  
Lisa Essich ◽  
Torsten Müller
Keyword(s):  
Biomass Production ◽  
Plant Biomass ◽  
Nutrient Content ◽  
Phosphorus Concentration ◽  
Available Phosphorus ◽  
Phosphorus Fertilizers ◽  
Future Supply ◽  
Application Techniques ◽  
Phosphorus Recycling ◽  
Fertilizing Effect

Despite phosphorus resources on Earth being limited, over fertilization in many agricultural situations causes significant resource consumption. Phosphorus-recycling within agricultural production can reduce global dilution into the environment and is thus essential to secure sustainable future supply. This study investigated the fertilization efficacy of phosphorus fertilizers recycled from biogas digestates in maize shoots grown under controlled greenhouse conditions, in two soils, in a pot experiment. Variables investigated were plant-available phosphorus in soil, plant biomass production, and concentration of phosphorus, calcium, and magnesium in shoots. Soils were treated with three different fertilizer fractions, separated from biogas digestates, at equivalent phosphorus concentrations, using different combinations and application techniques, isolated or in combination, and compared to triple superphosphate (TSP) as a reference. One of the fractions (P-Salt) had effects on biomass production and plant phosphorus concentration equivalent to TSP in agricultural surface soil. In the second soil (with less active soil life and nutrient content), equivalence to TSP was achieved with combinations of two recycled fractions (P-Salt and dried solids). The enhancement of the phosphorus fertilizing effect by the solids was synergistic, indicating that the solids had a soil conditioning effect. The results show that biogas digestates are a valuable source for phosphorus recycling of fractions that have equivalent or even superior fertilizing properties compared to TSP.

Phosphorus and land-use changes are significant drivers of cladoceran community composition and diversity: an analysis over spatial and temporal scales

2010 ◽  
Vol 67 (8) ◽  
pp. 1262-1273 ◽  
Author(s):  
Marc Richard Albert ◽  
Guangjie Chen ◽  
Graham K. MacDonald ◽  
Jesse C. Vermaire ◽  
Elena M. Bennett ◽  
...  
Keyword(s):  
Land Use ◽  
Community Composition ◽  
Time Series Data ◽  
Temporal Analysis ◽  
Phosphorus Loading ◽  
Series Data ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Watershed Disturbance ◽  
Subfossil Cladoceran

We conducted paleolimnological studies over spatial and temporal gradients to define the responses of subfossil cladoceran community composition and diversity to changes in land use and phosphorus concentrations in shallow lakes. We predicted that watershed disturbance by humans, through its impact on water quality, would explain significant variation in cladoceran diversity and composition. Across lakes, water-column total phosphorus concentration was a significant (p < 0.05) predictor of the subfossil cladoceran community composition. Chydorid diversity was also found to be related significantly to phosphorus concentration (r = –0.55, p < 0.05) and the proportion of disturbed land in the watershed (r = –0.47, p < 0.05). However, net load of phosphorus to the watershed rather than proportion of watershed disturbance was a significant predictor of chydorid diversity (r = –0.86, p < 0.001) in our temporal analysis of an eutrophying lake. Given that phosphorus loading to surface waters is often related to phosphorus concentrations in soils, we suggest that the net phosphorus load to the watershed is a more sensitive metric of land-use change and necessary for detecting ecological responses in time series data.

Forest harvest impacts on water quality and aquatic biota on the Boreal Plain: introduction to the TROLS lake program

2001 ◽  
Vol 58 (2) ◽  
pp. 421-436 ◽  
Author(s):  
E E Prepas ◽  
B Pinel-Alloul ◽  
D Planas ◽  
G Méthot ◽  
S Paquet ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Zooplankton Biomass ◽  
Phosphorus Concentration ◽  
Zooplankton Abundance ◽  
Total Phosphorus Concentration ◽  
Buffer Strip ◽  
Stratified Lakes ◽  
Lake Volume ◽  
Order Of Magnitude

Eleven headwater lakes in Alberta's Boreal Plain were monitored for nutrients and plankton 2 years before and 2 years after variable watershed harvesting (harvesting mean 15%, range 0-35%). After harvesting, variations in annual precipitation resulted in lake water residence times that differed by an order of magnitude from one year to the next. During the first posttreatment year, total phosphorus concentrations increased (overall 40%) in most lakes; however, response was most consistent in lakes that were shallow and the water column mixed or weakly thermally stratified. Chlorophyll a, cyanobacteria (Aphanizomenon-Anabaena), and cyanotoxins (microcystin-LR) increased after harvesting, primarily in shallow lakes. Zooplankton abundance and biomass decreased after harvesting, particularly in stratified lakes where edible phytoplankton biomass declined. In the weakly or nonstratified lakes, declines in zooplankton biomass were associated with higher cyanobacterial biomass and cyanotoxins. Posttreatment change in total phosphorus concentration was strongly related to weather (greatest response in a wet year) and relative drainage basin size (drainage basin area to lake volume, r2 = 0,78, P << 0,01). There was no evidence that buffer strip width (20, 100, and 200 m) influenced lake response. These results suggest that activities within the entire watershed should be the focus of catchment-lake interactions.

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