Abstract
Abstract. Published work on the reflectance of vegetation growing over soil mineralizations is reviewed. Experimental work was carried out on several species grown in a glasshouse and was extended to a pilot field study. In the laboratory studies, the most general effects of Cd, Cu, Pb or Zn were growth inhibition. A detailed study of the leaf pigments of pea plants showed that the chl a/chl b ratio (chl=chlorophyll) decreased under conditions of Cd or Cu stress but showed little effect with Pb or Zn. However, the absorption spectra of chloroplast pigments were not found to show any wavelength shifts with metal treatments, indicating that new spectral forms of chlorophyll were not produced as a stress response. A decrease in the total chlorophyll content of leaf tissue (fresh weight basis) was correlated with an increase in visible-wavelength leaf reflectance (R) of pea plants. R at infrared wavelengths of 0.85 μm, 1.65 μm and 2.20 μm decreased in metal-treated plants, compared with controls. Although experiments with other species, and a review of published literature, indicate that reflectance effects are dependent on species, phase of growth cycle and environment, the existence of correlations between R at certain wavelengths and the metal concentrations to which roots are exposed was confirmed using oak trees growing naturally in the area of a copper-arsenic mineralization in south-west England. Metal (Cu or As) concentrations in the soil were strongly negatively correlated (p > 99 per cent) with R at 1.65 μm and 2.20 μm, and positively correlated (p > 95 per cent) with R at 0.660 μm, in close agreement with the experiments on pea plants. The inclusion of the relevant infrared bands on Earth resource survey instruments is likely to enhance their usefulness for detecting heavy metal stress in plants.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Cd, Cu, Pb and Zn generally inhibited plant growth.
- Taxon
- plantsViridiplantaee1
- Treatment
- Cd, Cu, Pb or Zne0
- Outcome
- growthe0
- Direction
- inhibitione0
Not reportedComparator
Verbatim
e0“In the laboratory studies, the most general effects of Cd, Cu, Pb or Zn were growth inhibition.”
e1“A detailed study of the leaf pigments of pea plants showed that the chl a/chl b ratio (chl=chlorophyll) decreased under conditions of Cd or Cu stress”
Claim · model-written summary
Cd or Cu stress decreased the pea leaf chlorophyll a/b ratio.
- Taxon
- pea plants
Lathyrus oleraceuse0 - Organ / stage
- leafe0
- Treatment
- Cd or Cu stresse0
- Outcome
- chl a/chl b ratioe0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A detailed study of the leaf pigments of pea plants showed that the chl a/chl b ratio (chl=chlorophyll) decreased under conditions of Cd or Cu stress”
Claim · model-written summary
Pb or Zn had little effect on pea leaf chlorophyll a/b ratio.
Not reportedTaxonComparator
Verbatim
e0“but showed little effect with Pb or Zn.”
e1“A detailed study of the leaf pigments of pea plants showed that the chl a/chl b ratio (chl=chlorophyll) decreased under conditions of Cd or Cu stress”
Claim · model-written summary
Metal treatments produced no wavelength shifts in chloroplast pigment absorption spectra.
- Treatment
- metal treatmentse0
- Outcome
- absorption spectra of chloroplast pigmentse0
- Direction
- not found to show any wavelength shiftse0
Not reportedTaxonComparator
Verbatim
e0“the absorption spectra of chloroplast pigments were not found to show any wavelength shifts with metal treatments”
Claim · model-written summary
Decreased leaf chlorophyll correlated with increased visible reflectance in pea.
- Taxon
- pea plantsLathyrus oleraceuse0
- Organ / stage
- leaf tissuee0
- Compound
- total chlorophyll contente0
- Outcome
- visible-wavelength leaf reflectance (R)e0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A decrease in the total chlorophyll content of leaf tissue (fresh weight basis) was correlated with an increase in visible-wavelength leaf reflectance (R) of pea plants.”
Claim · model-written summary
Metal treatment decreased infrared reflectance at 0.85, 1.65 and 2.20 μm.
Verbatim
e0“R at infrared wavelengths of 0.85 μm, 1.65 μm and 2.20 μm decreased in metal-treated plants, compared with controls.”
Claim · model-written summary
Reflectance responses varied by species, growth phase and environment.
Not reportedTaxon
Verbatim
e0“reflectance effects are dependent on species, phase of growth cycle and environment”
Claim · model-written summary
Soil Cu or As was negatively correlated with oak reflectance at 1.65 and 2.20 μm.
- Compound
- Metal (Cu or As) concentrations in the soile0
- Outcome
- R at 1.65 μm and 2.20 μme0
- Direction
- negatively correlatede0
- Qualifier
- p > 99 per cente0
QuercusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Metal (Cu or As) concentrations in the soil were strongly negatively correlated (p > 99 per cent) with R at 1.65 μm and 2.20 μm”
e1“oak trees growing naturally in the area of a copper-arsenic mineralization in south-west England”
Claim · model-written summary
Soil Cu or As was positively correlated with oak reflectance at 0.660 μm.
- Compound
- Metal (Cu or As) concentrations in the soile0
- Outcome
- R at 0.660 μme0
- Direction
- positively correlatede0
- Qualifier
- p > 95 per cente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Metal (Cu or As) concentrations in the soil were strongly negatively correlated (p > 99 per cent) with R at 1.65 μm and 2.20 μm, and positively correlated (p > 95 per cent) with R at 0.660 μm”
e1“oak trees growing naturally in the area of a copper-arsenic mineralization in south-west England”
Claim · model-written summary
Including infrared bands was recommended to improve detection of plant metal stress.
- Taxon
- plantsViridiplantaee0
- Outcome
- inclusion of the relevant infrared bands on Earth resource survey instrumentse0
- Qualifier
- likely to enhance their usefulness for detecting heavy metal stresse0
Verbatim
e0“The inclusion of the relevant infrared bands on Earth resource survey instruments is likely to enhance their usefulness for detecting heavy metal stress in plants.”
The same questions in other papers
copper atom · growth · Viridiplantae (plants)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
1 paper more in this group
See all 5 papers →zinc atom · growth · Viridiplantae (plants)Positive and negative results
1 paper in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
1 paper more in this group
See all 5 papers →cadmium atom · growth · Viridiplantae (plants)Results agree
1 paper in the same direction as this paper
- negative
lead atom · growth · Viridiplantae (plants)Results agree
3 papers in the same direction as this paper
- negative
- negative
- no effect
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.