Nutrient deficits increase frost hardiness in Sitka spruce ( Picea sitchensis) needles

• Published in: Forest ecology and management 1998-08, Vol.107 (1), p.191-201
• Main Authors: Jalkanen, R.E, Redfern, D.B, Sheppard, L.J
• Format: Article
• Language: English
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; AZOTE; Biological and medical sciences; CARENCE EN SUBSTANCE NUTRITIVE; Climatic adaptation. Acclimatization; DAMAGE; DANOS; DEFICIENCIAS NUTRITIVAS; DEGAT; Electrolyte leakage; FEUILLE; FOSFORO; FROST; Fundamental and applied biological sciences. Psychology; GEL; General agronomy. Plant production; HELADA; HOJAS; LEAVES; NITROGEN; NITROGENO; NUTRIENT DEFICIENCIES; PHOSPHORE; PHOSPHORUS; PICEA SITCHENSIS; POTASIO; POTASSIUM; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; TEMPERATURE RESISTANCE; Visible damage scoring
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(97)00338-1

Frost hardiness of Sitka spruce ( Picea sitchensis (Bong.) Carr) trees growing in a nutrient deficiency trial was monitored between September and May by freezing detached shoots in a purpose built cabinet. Hardiness was assessed visually, as the temperature causing 50% shoot death (LT 50), and from measurements of electrolyte leakage. Trees, 14–20 years old, growing on a raised upland peat bog were given fertilizer applications designed to exacerbate macronutrient (N, P, K) deficiency. Depriving these trees of N, P and K resulted in N, P and K concentrations of 1-year-old needles of 1.01, 0.09 and 0.19% dry weight, respectively, whereas fertilized control trees whose nutrient concentrations were considered normal, resulted in concentrations of 1.43, 0.22 and 0.82% dry weight, respectively. The timing of autumn hardiness acquisition and the level of mid-winter hardiness were strongly influenced by nutrient deprivation. One-year-old shoots deprived of K were hardy to −20°C 5 weeks before shoots from the full nutrient treatment, and in mid January −K trees were 5 to 10°C harder than trees supplied with all three macronutrients. Likewise, prior to budburst in spring, −K trees were approximately 10°C harder than control trees. Similar, but smaller, effects were induced by deficiency of N and P. Effects of nutrient deprivation were greatest during the hardening phase and smallest over the winter period. Effects of needle age were detectable in autumn when 2-year-old needles were hardy to colder temperatures than 1-year-old needles. The observation that N, P or K deprivation increases frost hardiness in Sitka spruce is important in view of the concern over rising levels of N deposition.