Survival and growth of Picea glauca seedlings as a function of freezing temperatures and exposure times during budbreak and shoot elongation

Abstract

The impact of freezing temperatures and exposure times during budbreak and shoot elongation on 10-month-old containerized white spruce seedlings [Picea glauca (Moench) Voss] was studied. Seedlings were exposed to 0, −2, −4, −6, −8 and −10°C for 0, 1, 2, 3, 4, 5 and 6 h at four stages of budbreak and shoot elongation (stage 1: unswollen bud; stage 2: swollen bud; stage 3: bud scales parted by emerging needles; stage 4: 1–5 cm of terminal shoot growth). Seedling and terminal bud survival, viability of first-year needles (developed before frost exposure), terminal shoot length, stem diameter and aerial dry mass were measured 90 days after freezing exposure. Frost severity had a much greater influence on seedling survival, damage and subsequent growth than exposure time. The bud development stage at which freezing temperatures were applied also affected survival and subsequent growth.

Keywords:

• Cold tolerance
• forest nurseries
• seedling survival
• spring frost

Acknowledgments

We thank Yves Dubuc for his technical assistance, Michèle Bernier-Cardou for statistical supervision and Sylvain Boisclair for statistical analyses. We also thank Pampev Inc. and the ministère des Ressources naturelles, de la Faune et des Parcs du Québec, for providing the seedlings. This research was funded by the ministère des Ressources naturelles, de la Faune et des Parcs du Québec, the Natural Sciences and Engineering Research Council of Canada and the Biotechnology Network of Natural Resources Canada – Canadian Forest Service.

Notes

Bigras, F. J. ¹ , Coursolle, C. ² and Margolis, H. A. ² (¹Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 3800, Sainte-Foy, QC, Canada, G1V 4C7, and ²Faculté de Foresterie et de Géomatique, Université Laval, Québec, QC, Canada, G1K 7P4). Survival and growth of Picea glauca seedlings as a function of freezing temperatures and exposure times during budbreak and shoot elongation.

Additional information

Notes on contributors

Francine J. Bigras

Bigras, F. J. 1 , Coursolle, C. 2 and Margolis, H. A. 2 (1Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 3800, Sainte-Foy, QC, Canada, G1V 4C7, and 2Faculté de Foresterie et de Géomatique, Université Laval, Québec, QC, Canada, G1K 7P4). Survival and growth of Picea glauca seedlings as a function of freezing temperatures and exposure times during budbreak and shoot elongation.