Experiment 2: Effects of individual Rare Earth Elements (La, Nd, Ce) on terrestrial crop and native plants: uptake, accumulation and effects of calcium level in the test medium
The objective of this experiment was to examine the effect of calcium (Ca) addition/shortage on plant sensitivity to Rare Earth Elements (REEs). It was postulated that REEs are able to exert effects on plants due to their similarity in ionic radii to Ca. As Ca is vital to many physiological processes, competition with the REEs may lead to undesirable effects on plant health. Due to the assumed link between REEs and Ca availability, it was hypothesized that plant sensitivity to REEs (as indicated by lower germination and biomass inhibition concentrations) would increase when exposed to lower soil Ca levels. Three Ca concentrations were assessed at two pH levels and three REE doses. Two species were tested: the native common milkweed, Asclepias syriaca as well as the crop tomato, Solanum lycopersicum var. Beefsteak. Experiments were conducted in NWRC greenhouses of Environment and Climate Canada with plants tested individually in pots. Three REEs were investigated in separate experiments: lanthanum (La), neodymium (Nd) and cerium (Ce). Concentrations of Ca and REEs were determined. At a given pH level, measured Ca concentrations in roots and shoots tended to increase with increasing soil Ca levels from the low Ca to the medium Ca treatment, but there was little difference between the medium Ca and high Ca soil treatments, indicating a threshold. Aboveground shoot Ca concentrations in both species were generally higher than their corresponding root measures. The worst case scenario for REE uptake and accumulation in the roots and shoots of both species would be at low soil pH and generally at low soil calcium levels. No effect of any REEs was detected on percent seed germination while some subtle and mixed effects were observed on speed of germination. There was generally a significant reduction in shoot and root biomass in both S. lycopersicum and A. syriaca due to REEs. The concentration of Ce in the soil had more of an effect on the two plant species than was observed in La and Nd experiments. There was generally an increase in biomass with addition of soil Ca. Many interactions between REE concentrations, Ca and pH were significant meaning that the relationships between these variables were not linear.
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Metadata Record Information
- File Identifier
- 8b53889d-9d9c-484d-b03f-72806ac61a9b XML
- Date Stamp
- 2021-05-12T06:01:28
- Metadata language
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eng; CAN
- Character set
- UTF8
- Hierarchy Level
- Series
http://ec.gc.ca
Data identification
- Date (Publication)
- 2018-05-24
- Date (Creation)
- 2018-05-24
- Status
- Completed
- Metadata language
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eng; CAN
- Character set
- UTF8
- Topic category
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- Biota
- Maintenance and Update Frequency
- As needed
- Spatial representation type
- Vector
613 998 0458
Keywords
- Theme
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Rare Earth Element, metal, Toxicology, Terrestrial plant, lanthanum, neodymium, cerium
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Substance
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Government of Canada Core Subject Thesaurus
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Toxicology
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ECCC Information Category EN
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Nature and Biodiversity - Contaminants
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Business Functions
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Assess Toxicity, Manage and Monitor for Environmental Presence of Hazardous Substances and Waste
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Assess Toxicity of Substance
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Geography
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National (CA)
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external.theme.EC_Branch
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Science and Technology Branch
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external.theme.EC_Directorate
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Wildlife and Landscape Science
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external.theme.GC_Security_Level
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Unclassified
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- Use Limitation
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Open Government Licence - Canada ( http://open.canada.ca/en/open-government-licence-canada )
- Access Constraints
- License
- Use Constraints
- License
- Begin Date
- 2017-04-03
- End Date
- 2018-03-30
Extent
))
Ref. system Reference Systems
- Reference system identifier
- EPSG / 4326 / inconnue
Distribution
Distribution Formats
- Distribution format
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CSV
(
Inconnue
)
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CSV
(
Inconnue
)
http://ec.gc.ca
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