Soil nutrient regime classification for white spruce stands in the Sub-boreal Spruce Zone of British Columbia

Using mineralizable N (kg/ha) and C/N ratio measured within the rooting zone as differentiating characteristics, 93 white spruce (Picea glauca (Moench) Voss) stands from the Sub-boreal Spruce Biogeoclimatic Zone of British Columbia were quantitatively classified into five soil nutrient regimes (i.e., very poor, poor, medium, rich, and very rich) by cluster analysis and discriminant analysis. Significant differences in soil chemical properties, frequencies of nitrogen indicator species groups, foliar nutrients, and site index were found among the five soil nutrient regimes. The classification compared favorably (60% match) with the field classification based on topographic and soil morphological features using a dichotomous key. By relating each soil nutrient regime to the quantities of soil nutrients available to plants traditional site classification units can be directly linked to resource availability, thus potential productivity, of the sites. It is recommended that further studies of soil nutrient regime classification in the Sub-boreal Spruce Biogeoclimatic Zone should concentrate on characterizing the regional gradient of soil available nitrogen.