Open AccessThe carbon implications of large‐scale afforestation of agriculturally marginal land with short‐rotation willow in S askatchewan
Author(s) -
Amichev Beyhan Y.,
Kurz Werner A.,
Smyth Carolyn,
Rees Ken C. J.
Publication year - 2012
Publication title -
gcb bioenergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.378
H-Index - 63
eISSN - 1757-1707
pISSN - 1757-1693
DOI - 10.1111/j.1757-1707.2011.01110.x
Subject(s) - willow , short rotation coppice , coppicing , marginal land , afforestation , short rotation forestry , biomass (ecology) , environmental science , bioenergy , agroforestry , agronomy , carbon sequestration , forestry , woody plant , biology , biofuel , ecology , geography , agriculture , carbon dioxide
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 for SRC systems in the province of S askatchewan, C anada; (ii) the potential biomass yields of SRC plantations; 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 the B oreal P lains and P rairies ecozones in S askatchewan. The P hysiological P rinciples in P redicting G rowth (3 PG ) model was calibrated with data from SRC experiments in S askatchewan, to quantify potential willow biomass yields, and the C arbon B udget M odel of the C anadian F orest S ector ( CBM ‐ CFS 3), was used to simulate stand and landscape‐level C fluxes and stocks. Short‐rotation willow plantations managed in 3 year rotations for seven consecutive harvests (21 years) after coppicing at Y ear 1 produced about 12 Mg ha −1 yr −1 biomass. The more significant contribution to the C cycle was the cumulative harvest. After 44 years, the potential average cumulative harvested biomass C in the P rairies was 244 Mg C ha −1 (5.5 Mg C ha −1 yr −1 ) about 20% higher than the average for the B oreal P lains, 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 of CO 2 accumulation in the earth's atmosphere and further research is needed to operationalise such a mitigation effort.