Carbon storage in a chronosequence of red spruce (Picea rubens) forests in central Nova Scotia, Canada

Red spruce ( Picea rubens Sarg.) forests are an ecologically and economically important forest type in eastern Canada. We quantified the carbon (C) stocks of natural red spruce dominated stands in central Nova Scotia. Twenty-four stands over a 140 year chronosequence were sampled. Within each stand, major C pools including above- and below-ground tree biomass, shrub and herb vegetation, dead organic matter, and upper (0–10 cm) mineral soil were measured. A nonlinear four-parameter logistic function was fitted to the total site C stock data to describe the change in total ecosystem C storage over time. Total site C storage increased throughout stand development in a general sigmoidal pattern, increasing from 94.4 Mg C·ha –1 in the youngest age-class to a maximum of 247.0 Mg C·ha –1 in the 81- to 100-year-old age-class, then decreasing in the oldest age-classes. Carbon pools of live vegetation, standing dead trees, and downed woody debris displayed recognizable changes in C storage throughout stand development, conforming to some of the fundamental ideas on forest stand dynamics. Overall, above- and below-ground tree biomass had the greatest influence on total site C storage dynamics. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate carbon stocks at the regional scale.