ABSTRACT
In Canada, the coniferous forest was generally found to be nitrogen (N) deficient, but base cation deficiencies may be becoming more prevalent. Newly-developed nutritional standards based on leaf nutrient concentrations and compositional nutrient diagnosis (CND) were applied on published data of white spruce nutrition from sites across Canada. Results suggest that nutritional disorders in white spruce are not restricted to N deficiencies. Based on nutrient concentrations, deficiencies are common, particularly in phosphorus (P), potassium (K), and calcium (Ca), but toxicities are rare. The CND analysis revealed some cases of excess N, P, and magnesium (Mg).
ACKNOWLEDGMENTS
The research was supported in part by the Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT), the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Centre of Excellence on Sustainable Forest Management Network (SFMN).
Notes
1Deficient and excessive correspond to more than a 10% reduction in growth relative to optimum concentrations.
1Critical Mg scores were extrapolated from the regression equation to enable the computation of IMg(CitationQuesnel et al., 2006).
2Limiting or excess when Index is < −1 or > 1, respectively; corresponds to more than 10% reduction in growth compared to optimum nutrition.