The carbon implications of large‐scale afforestation of agriculturally marginal land with short‐rotation willow in S askatchewan
Year: 2011
Type: article
Abstract: Afforestation with short‐rotation coppice (SRC) willow plantations for the purpose of producing bioenergy feedstock was contemplated as one potential climate change mitigation option. The objectives of this study were to assess the magnitude of this mitigation potential by addressing: (i) the land area potentially available forSRCsystems in the province ofSaskatchewan,Canada; (ii) the potential biomass yields ofSRCplantations; and (iii) the carbon implications from such a large‐scale afforestation program. Digital soils and land‐use data were used to identify, map, and group into clusters of similar polygons 2.12 million hectares (Mha) of agriculturally marginal land that was potentially suitable for willow in theBorealPlains andPrairies ecozones inSaskatchewan. ThePhysiologicalPrinciples inPredictingGrowth (3PG) model was calibrated with data fromSRCexperiments inSaskatchewan, to quantify potential willow biomass yields, and theCarbonBudgetModel of theCanadianForestSector (CBM‐CFS3), was used to simulate stand and landscape‐levelCfluxes and stocks. Short‐rotation willow plantations managed in 3 year rotations for seven consecutive harvests (21 years) after coppicing atYear 1 produced about 12 Mg ha−1 yr−1biomass. The more significant contribution to theCcycle was the cumulative harvest. After 44 years, the potential average cumulative harvested biomassCin thePrairies was 244 Mg C ha−1(5.5 Mg C ha−1 yr−1) about 20% higher than the average for theBorealPlains, 203 Mg C ha−1(4.6 Mg C ha−1 yr−1). This analysis did not consider afforestation costs, rate of establishment of willow plantations, and other constraints, such as drought and disease effects on biomass yield. The results must therefore be interpreted as a biophysical mitigation potential with the technical and economic potential being both lower than our estimates. Nevertheless, short‐rotation bioenergy plantations offer one potential mitigation option to reduce the rate ofCO2accumulation in the earth's atmosphere and further research is needed to operationalise such a mitigation effort.
Source: GCB Bioenergy
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2016979679