Frost hardiness in bark and needles of Norway spruce in southern Sweden

Abstract

Bark necrosis and resin flows in Norway spruce have increased in southern Sweden over the last few decades. Frost damage late in spring has been suggested as a possible cause, but other factors besides the climate may have contributed to the damage. The nutrient status influences the hardening processes and plants with poor nutritional conditions have an increased sensitivity to frost. In this study the sensitivity to frost of bark and the hardiness status of needles of Norway spruce were compared with the nutrient status at two sites with different soil fertility. The trees were 30-40 years old. The hardiness status of the bark and needles was negatively affected by low concentrations of P and Mg.

Excess nitrogen affects the frost sensitivity of the inner bark of Norway spruce

“…In another study on 30-40 year-old Norway spruce in southern Sweden, the frost sensitivity of the bark and hardiness status of needles were related to the concentrations of P and Mg in bark and needles, which in turn was related to differences in soil fertility between the study sites. The results also indicated influence of K [20]. Both this and the present study support the hypothesis that nutrient imbalances increases the risk for development of frost related bark lesions in southern Sweden.…”

“…Also, a correlation to nutrient concentrations and ratios can only be expected if there is a difference between the trees studied [20]. For instance, the Cu/N ratio was below the level considered optimal in all treatments, hence all trees were affected approximately equally and a potential influence on frost sensitivity and carbohydrate concentrations is then less likely to be detected.…”

Frost sensitivity and nutrient status in a fertilized Norway spruce stand in Denmark

“…Also low hardiness status of Norway spruce needles has been related to low levels of P and Mg in needles (Jönsson et al, 2001). These studies support the general conclusion that nutrient deficiencies increase the frost sensitivity, and that maximal frost resistance is obtained with a balanced nutrient status, adequate for normal growth (Bigras et al, 2001).…”

“…Due to the correlation between the concentrations of P and K, it is difficult to attribute the difference in frost sensitivity to either P or K. The frost sensitivity of Norway spruce bark, also measured as an index of injury, has been related to low levels of P, Mg and K in needles and bark (Jönsson et al, 2001;Jönsson et al, 2004). Also low hardiness status of Norway spruce needles has been related to low levels of P and Mg in needles (Jönsson et al, 2001).…”

Differences in frost hardiness of two Norway spruce morphotypes growing at Mt. Brocken, Germany

“…the ability of hardening and dehardening (Beck et al, 2004). Hardening and dehardening are strongly affected by ambient temperature (Jönsson et al, 2004;Søgaard et al, 2009), day length/photoperiod (Beck et al, 2004;Beuker et al, 1998), nutrients (Jönsson et al, 2001) and drought stress (Beck et al, 2007). While the initiation of hardening in autumn is mainly driven by photoperiod, the dehardening in spring is mainly regulated by temperature (Beck et al, 2004).…”