Field level evaluation and risk assessment of the toxicity of dichloroacetic acid to the aquatic macrophytes Lemna gibba, Myriophyllum spicatum, and Myriophyllum sibiricum

The potential of three aquatic macrophytes, Azoll caroliniana, Salvinia minima and Lemna gibba, was evaluated in this work aimed at selection of plants to be used in remediation of environments contaminated by arsenic (As). The experiments were carried out in a greenhouse during six days in pots containing Hoagland solution (¼ ionic strength) at As concentrations of 0.5; 2.5 and 5.0 mg L-1. The three species showed greater As accumulation as the concentration of the metalloid in solution increased. However, a reduction was detected in fresh and dry mass gain when the plants were exposed to high As concentrations. The macrophytes showed differences in efficiency of removal of As in solution. A. caroliniana, S. minima and L. gibba accumulated, on average, 0.130; 0.200; and 1.397 mg mDM-1, respectively, when exposed to 5.0 mg L-1 of As. The macrophytes absorbed a greater quantity of As in solution with low phosphate content. The greater As concentration in L. gibba tissues lowered the chlorophyll and carotenoid contents as shown by the high chlorosis incidence. Lemna gibba also exhibited a decrease in leaf size, with the total chlorophyll and carotenoid synthesis not being affected by As in A. caroliniana. This species exhibited purplish leaves with high concentration of anthocyanin, whose presence suggested association to phosphate deficiency. Marginal necrosis occurred on S. minima floating leaves, with the released daughter-plants not showing any visual symptoms during the treatment. The percentage of As removed from the solution decreased when the plants were exposed to high concentrations of the pollutant. Among the three species studied, only L. gibba could be considered an As hyper-accumulator. The use of this plant species for remediation of aquatic environments was shown to be limited and requires further investigation.

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CHEMICAL COMPOSITION OF AQUATIC MACROPHYTES I. INVESTIGATION OF ORGANIC CONSTITUENTS AND NUTRITIONAL POTENTIAL

Canadian Journal of Plant Science ◽

10.4141/cjps78-122 ◽

1978 ◽

Vol 58 (3) ◽

pp. 829-841 ◽

Cited By ~ 12

Author(s):

A. JABBAR MUZTAR ◽

S. J. SLINGER ◽

J. H. BURTON

Keyword(s):

Dry Matter ◽

Aquatic Macrophytes ◽

Nutritive Value ◽

Myriophyllum Spicatum ◽

Ash Content ◽

Neutral Detergent Fiber ◽

Mineral Matter ◽

Cladophora Glomerata ◽

Additional Processing ◽

Gross Energy

Chemical analyses were conducted on unwashed samples of four aquatic plant species harvested at three progressive dates during 1974. All species showed an extremely high ash content. The ash content increased in Potamogeton spp. with progress in the harvesting time and varied only slightly in Cladophora glomerata. Myriophyllum spicatum and Vallisneria americana, harvested in September, were second growth, which was reflected in the much lower ash and considerably higher organic nutrient levels. The neutral-detergent fiber (NDF) level tended to be higher in all species for samples harvested in September. Acid-detergent fiber (ADF) was also higher during the same month except in Potamogeton spp. With the exception of Potamogeton spp., the level of acid-detergent lignin (ADL) was similar in all species at the different dates. Both NDF and ADF values were inflated because of unavoidable contamination with mineral matter. A further experiment with washed and unwashed plant samples harvested the following year showed that washing decreased the ash content markedly, in most cases with a concomitant increase in proximate constituents and gross energy values. All species, either washed or unwashed, were very low in dry matter (5–20%); the NDF and ADF levels for most plants were similar to those of alfalfa, while ADL content was relatively low. Results indicated that aquatic macrophytes would have nutritive value similar to alfalfa; however, their high ash and low dry matter contents would necessitate quality control and additional processing for possible use as feedstuffs.

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Genetic diversity and differentiation in populations of invasive Eurasian (Myriophyllum spicatum) and hybrid (Myriophyllum spicatum × Myriophyllum sibiricum) watermilfoil

Invasive Plant Science and Management ◽

10.1017/inp.2020.12 ◽

2020 ◽

Vol 13 (2) ◽

pp. 59-67

Author(s):

Ryan A. Thum ◽

Gregory M. Chorak ◽

Raymond M. Newman ◽

Jasmine A. Eltawely ◽

Jo Latimore ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

Population Genetic ◽

Myriophyllum Spicatum ◽

Population Variation ◽

Efficacy Evaluation ◽

Submerged Aquatic Plant ◽

Myriophyllum Sibiricum ◽

Control Response ◽

Herbicide Response

AbstractPopulation genetic studies of within- and among-population genetic variability are still lacking for managed submerged aquatic plant species, and such studies could provide important information for managers. For example, the extent of within-population genetic variation may influence the potential for managed populations to locally adapt to environmental conditions and control tactics. Similarly, among-population variation may influence whether specific control tactics work equally effectively in different locations. In the case of invasive Eurasian watermilfoil (Myriophyllum spicatum L.), including interspecific hybrids with native northern watermilfoil (Myriophyllum sibiricum Kom.), managers recognize that there is genetic variation for growth and herbicide response. However, it is unclear how much overall genetic variation there is, and how it is structured within and among populations. Here, we studied patterns of within- and among-lake genetic variation in 41 lakes in Michigan and 62 lakes in Minnesota using microsatellite markers. We found that within-lake genetic diversity was generally low, and among-lake genetic diversity was relatively high. However, some lakes were genetically diverse, and some genotypes were shared across multiple lakes. For genetically diverse lakes, managers should explicitly recognize the potential for genotypes to differ in control response and should account for this in monitoring and efficacy evaluation and using pretreatment herbicide screens to predict efficacy. Similarly, managers should consider differences in genetic composition among lakes as a source of variation in the growth and herbicide response of lakes with similar control tactics. Finally, laboratory or field information on control efficacy from one lake may be applied to other lakes where genotypes are shared among lakes.

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Synergy of High-Resolution Radar and Optical Images Satellite for Identification and Mapping of Wetland Macrophytes on the Danube Delta

Remote Sensing ◽

10.3390/rs12142188 ◽

2020 ◽

Vol 12 (14) ◽

pp. 2188 ◽

Cited By ~ 2

Author(s):

Simona Niculescu ◽

Jean-Baptiste Boissonnat ◽

Cédric Lardeux ◽

Dar Roberts ◽

Jenica Hanganu ◽

...

Keyword(s):

Time Series ◽

Aquatic Macrophytes ◽

Aquatic Vegetation ◽

Myriophyllum Spicatum ◽

Danube Delta ◽

Backscatter Coefficient ◽

Macrophyte Communities ◽

Optical Images ◽

Detailed Classification ◽

Floating Vegetation

In wetland environments, vegetation has an important role in ecological functioning. The main goal of this work was to identify an optimal combination of Sentinel-1 (S1), Sentinel-2 (S2), and Pleiades data using ground-reference data to accurately map wetland macrophytes in the Danube Delta. We tested several combinations of optical and Synthetic Aperture Radar (SAR) data rigorously at two levels. First, in order to reduce the confusion between reed (Phragmites australis (Cav.) Trin. ex Steud.) and other macrophyte communities, a time series analysis of S1 data was performed. The potential of S1 for detection of compact reed on plaur, compact reed on plaur/reed cut, open reed on plaur, pure reed, and reed on salinized soil was evaluated through time series of backscatter coefficient and coherence ratio images, calculated mainly according to the phenology of the reed. The analysis of backscattering coefficients allowed separation of reed classes that strongly overlapped. The coherence coefficient showed that C-band SAR repeat pass interferometric coherence for cut reed detection is feasible. In the second section, random forest (RF) classification was applied to the S2, Pleiades, and S1 data and in situ observations to discriminate and map reed against other aquatic macrophytes (submerged aquatic vegetation (SAV), emergent macrophytes, some floating broad-leaved and floating vegetation of delta lakes). In addition, different optical indices were included in the RF. A total of 67 classification models were made in several sensor combinations with two series of validation samples (with the reed and without reed) using both a simple and more detailed classification schema. The results showed that reed is completely discriminable compared to other macrophyte communities with all sensor combinations. In all combinations, the model-based producer’s accuracy (PA) and user’s accuracy (UA) for reed with both nomenclatures were over 90%. The diverse combinations of sensors were valuable for improving the overall classification accuracy of all of the communities of aquatic macrophytes except Myriophyllum spicatum L.

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