Claim · model-written summary
Daily absorbance changes of chlorophyll extracts had a linear relation with pyrheliometer light sums.
- Outcome
- cumulative light sumse0
- Qualifier
- linear relationship over timee0
- Comparator
- changes in absorbance at 660 nme0
Pinus
QuercusNot reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleTreatmentSettingDirectionValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On each day, there was a linear relationship over time between changes in absorbance at 660 nm of the chlorophyll extracts and cumulative light sums in g cal/cm2 as measured by an Eppley pyrheliometer”
e1“under oak and pine canopies”
Title
Measurement of Solar Radiation Under Forest Canopies by Use of Chlorophyll Extracts
Frederick R. Swan; Helmut Lieth Journal of Biogeography 1976. doi:10.2307/3038014
Other claims from this paper (10)
- Method / resource Chlorophyll extracts allowed many simultaneous radiation measurements at heights up to 4-5 m.
- Method / resource Chlorophyll extracts were more practical than solarimeters and pyranometers for inexpensive simultaneous daily light measurements.
- Method / resource Chlorophyll extracts gave less reproducible results than solarimeters and pyranometers.
- Observation Oak-stand transmittance was reported as 590% less than pine-stand transmittance.
- Observation Oak-stand basal area was 150% greater than pine-stand basal area.
- Observation Daily average light sums in pine stands were 33-509 % greater than in oak stands.
- Observation Seedlings, mostly hardwoods, were twice as dense in pine stands as in oak stands.
- Observation The average range of daily light sums was 2 6 times greater in pine stands.
- Observation On three of five days, light sums under pine tree canopies alone exceeded those under other canopy combinations.
- Association Seedling species showed random distributions with respect to measured light, except red maple in the pine stand.