Canadian Forest Service Publications
Growth and ABA responses of maple seedlings to aluminum. 1995. Bertrand, A.; Robitaille, G.; Boutin, R.; Nadeau, P. Tree Physiology 15: 775-782.
Issued by: Laurentian Forestry Centre
Catalog ID: 16728
Availability: PDF (request by e-mail)
We assessed the impacts of low pH and 2.0 mM aluminum (Al) on the growth of sugar maple (Acer saccharum Marsh.) seedlings over a 13-week period. At Week 9, total leaf area of Al-treated seedlings was reduced by 27%; however, by Week 13, leaf area was similar for seedlings in all treatments. None of the other growth parameters examined were negatively affected by the treatments at either Week 9 or Week 13. The ABA concentration in the xylem sap, which is an indicator of tree stress in the field, was not affected by any of the treatments and was highest during periods of high evaporative demand in June and August. We conclude that the duration of exposure to Al is critical when assessing a threshold concentration for Al toxicity because plants can acclimate to an Al concentration previously considered toxic. Although Al stress did not appear to reduce the vigor of sugar maple seedlings directly, it could facilitate an inciting factor such as winter frost to induce tree decline.