Carbon Sequestration Potential of Shelterbelt Agroforestry Systems.

Sequestration of carbon in soils, through the implementation of agroforestry practices, is identified as one of the major strategies in the reduction of greenhouse gases by the Intergovernmental Panel on Climate Change (IPCC). This study determines the potential of hardwood and conifer shelterbelts across the soil zones of Saskatchewan for belowground sequestration of soil organic carbon (SOC) at the farm landscape scale. Carbon sequestered under shelterbelts was determined by measuring the SOC under shelterbelts and comparing it to the adjoining fields in order to determine the increase in SOC pools due to shelterbelts. Our study indicates that shelterbelts have significantly higher amount of SOC compared to the adjacent agricultural fields. The average yearly accrual of SOC under the shelterbelts varied from 0.7-1 t ha^-1 yr^-1. Carbon sequestration under the shelterbelts was dependent on the shelterbelt species as well as the age of the shelterbelts. The average increase in the pools of SOC under the shelterbelts compared to the adjacent fields, was determined to be 14 t C/ha under caragana (Caragana arborescens) shelterbelts, 17 t C/ha under white spruce (Picea glauca) shelterbelts and 32 t C/ha under the hybrid poplar (Populus spp.) shelterbelts. The average increase in SOC pools under the shelterbelts increased from 16% for the shelterbelts aged less than 30 years, to 40% for shelterbelts aged more than 30 years across all shelterbelt species. Higher amount of SOC under shelterbelts compared to cultivated fields indicates that shelterbelt plantations can be an effective management strategy for carbon sequestration.