Claim · model-written summary
Thirteen percent of the tallest Populus hybrid reached the mean height of dominant and codominant alder after six years.
Populus
AlnusNot reportedGeneCompoundOrgan / stageSecond interactorSecond interactor roleTreatmentComparatorSettingDirectionQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 6 years, only 2% of the Populustrichocarpa Torr. & Gray clone and 13% of the tallest Populus hybrid were equal to or above the mean height of alder dominants and codominants (6.2 m).”
Title
Paul E. Heilman Canadian Journal of Forest Research 1990. doi:10.1139/x90-012
Other claims from this paper (12)
- Observation Populus grew abnormally slowly and was overtopped by a dense alder stand by year three.
- Observation Soil nitrogen content rose on average by 56 kg per hectare per year.
- Observation Populus foliar nitrogen rose significantly from 0.69% in year two to 2.06% in year seven.
- Observation Height growth of the largest Populus increased from below 0.5 m/year in the first three years to above 1.0 m/year in years five and six.
- Intervention effect Nitrogen and nitrogen-plus-phosphorus fertilizer increased Populus height growth in 1982 and the following year, totaling 64%.
- Intervention effect After 1984 fertilizer had no significant effect on Populus height growth, total height or diameter.
- Intervention effect Nitrogen fertilization increased Populus foliar nitrogen significantly in the treatment year.
- Intervention effect Phosphorus fertilization did not significantly affect growth or foliar phosphorus concentration.
- Observation Only 2% of the Populus trichocarpa clone reached the mean height of dominant and codominant alder after six years.
- Observation Populus cross-sectional area was only 8% of that of normal trees for its height.
- Recommendation The authors concluded that Populus may not compete satisfactorily with alder on low-nitrogen mudflow sites.
- Observation The paper contrasts high-nitrogen sites, where red alder cannot compete with Populus.