Short Rotation Woody Crop Site Suitability: Willow

This data depicts site suitability for the establishment of area-based Short Rotation Woody Crops (SRWC) of willow on lands eligible (i.e. non-forested) for afforestation across Canada.

Determining the feasibility of a large-scale afforestation program is one approach being investigated by the Government of Canada to increase Canada's potential to sequester carbon from the atmosphere and/or produce bioproducts and bioenergy. Large-scale afforestation, however, requires knowledge of where it is suitable to establish and grow trees. Spatial models based on Boolean logic and/or statistical models within a geographic information system may be used for this purpose, but empirical environmental data are often lacking, and the association of these data to land suitability is most often a subjective process. As a solution to this problem, a fuzzy-logic modeling approach to assess site suitability for afforestation of hybrid poplar (Populus spp.) and willow (Salix spp.) in Canada was developed. Expert knowledge regarding the selection and magnitudes of environmental variables were integrated into fuzzy rule sets from which estimates of site suitability were generated and spatially presented. The environmental variables selected included growing season precipitation, climate moisture index, growing degree days, the Canada Land Inventory capability for agriculture and elevation.

Site suitability is generally defined as the fitness of a given type of land for a particular use. For this assessment, site suitability was defined as the fitness of edaphic, climatic and topographic conditions to establish and grow SRWC species at rates 8 times those of native species. Suitability index values range from 1-100, with higher values corresponding to higher suitability. Approximately 246,000 km2, or 38% of the eligible land base within Canada was found to be suitable for afforestation using Short Rotation Woody Crops (SRWC) of hybrid poplar and/or willow.