Carbon Inventory Maps of Planted White Spruce Shelterbelts in Saskatchewan, Canada.

For more than a century, planted shelterbelt trees in Saskatchewan, Canada have provided protection of farmyards from the elements, soil protection from erosion, carbon sequestration and storage, and a myriad of other environmental functions. It is estimated that there are >60,000 km of planted shelterbelts throughout the province, and considerably more in the Canadian Prairies. The overall process of quantifying and mapping the carbon storage capacity in all white spruce (Picea glauca) shelterbelts planted in Saskatchewan was demonstrated. Shelterbelt data collected from field sampling sites, which were located by a unique site selection approach, were used to parameterize two models for use in shelterbelt systems; a separate data set was used to validate model predictions. Tree growth was modeled with the Physiological Principles in Predicting Growth (3PG) model, and carbon flux and stocks in shelterbelts were modeled with the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3). Annual total ecosystem carbon (TEC) flux increased one order of magnitude, from -0.33 to 4.4 MgCkm^-1yr^-1, for age 1-25 years, and reached a peak of 5.5 MgCkm^-1yr^-1 (age 39 years). An initial carbon loss from the shelterbelt soil was offset in full by tree growth by age 17, 18, and 21 years for trees planted at 2.0, 3.5, and 5.0 m spacing within a row, respectively. Carbon stocks, after 60 years of growth, increased in the litter layer (21.8 MgCkm^-1), below- (26.1 MgCkm^-1) and above-ground biomass (117.6 MgCkm^-1). The 60-yr carbon additions ranged 106-195 MgCkm^-1, totaling 50,440 MgC province-wide in 991 km of white spruce shelterbelts, planted in multiple decades. The C additions represented 38% of the province-wide TEC stocks, which totaled 131,750 MgC (=483,000 MgCO₂-eq.). The cumulative carbon storage capacity in all components of planted shelterbelts far exceeded the initial carbon levels present at the time of shelterbelt planting.