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The current context of ecological transition and the fight against climate change have revived interest in short-rotation coppice (SRC) of woody crops for bioenergy or bioproduct purposes. To determine the growth and yield potential of different willow cultivars, plantations were established in five regions of Quebec (Canada) across a wide climatic gradient. The present study compares results obtained after six years of cultivation at two coppicing frequencies (two and three years). Although annual yields approaching 20 tons ha−1 have been recorded at several of the study sites, little difference in the productivity of the tested cultivars was found, except for Salix viminalis "5027", which was generally less productive. Overall productivity was weakest at La Morandière, the northernmost site. Neither frequency of coppicing lead to a difference in yields. At La Pocatière, one of the coldest regions in this study, yields of cultivars were comparable to those recorded at the southernmost sites. Moreover, the highest cumulative yield after six years was recorded at that site with the cultivar "SV1". The fact that yields at most sites remain high after several years is indicative of the production potential of willow crops in SRC for Eastern Canada. [ABSTRACT FROM AUTHOR]

Abstract: Maintaining the long-term productivity of short-rotation coppice plantations is very important to ensure the large-scale deployment of biomass as a renewable energy source. In Quebec (Canada), willow short rotation coppice has been studied since the early ‘90s, thereby allowing long-term analysis of the dynamic performance of several species and hybrids as well as management practices. In this study, we report on the long-term productivity of two trials maintained in southern Quebec and carried out to compare a) growth and biomass yield of willow Salix viminalis (cultivar 5027) grown for 15 years under fertilized and unfertilized conditions and b) growth of different willow cultivars over three successive rotations (10 years). The first trial showed that after four rotations, sludge-fertilized S. viminalis 5027 produced significantly more biomass, 19.2 odt ha−1 yr−1, whereas unfertilized plots yielded 13.8 odt ha−1 yr−1. The second trial showed that among the wide variety of commercial willow cultivars available, SX64 and SX61 along with some indigenous species (i.e. S25, S365, S546) were the most suitable for short-rotation forestry in southern Quebec. [Copyright &y& Elsevier]

Increasing global populations, finite arable land, and the anthropogenic release of carbon dioxide into the atmosphere are driving the search for bio-based alternatives to the petroleum-derived fuels and chemicals that underpin the global economy. With rapid growth rates, a propensity for coppicing, and a wide geographic range across Canada, native shrub willows (Salix spp.) are an attractive source of low-input, high-volume biomass. To date, most willow research has focused on increasing yields and improving cropping systems, while comparatively little work has been done to assess the intrinsic diversity in cell wall traits and bioenergy potential. In this study, we characterized the cell wall composition and wood ultrastructure of 338 xylem samples from two Canadian willow species, Salix famelica and Salix eriocephala , harvested from a common garden experimental plot. Lignin content ranged from 17.5–25.1% in S. famelica and 18.6–24.3% in S. eriocephala. Following alkali pretreatment with 62.5 mM NaOH at 90 °C for 3 h and a 70-h enzymatic digestion with Accellerase 1000, glucose release ranged from 23.0–38.9 wt% in S. famelica and from 20.5–37.7 wt% in S. eriocephala , while xylose release ranged from 9.4–14.9% in S. famelica and from 9.5–15.2% in S. eriocephala. Partial least squares regression modelling showed that lignin content and composition were important negative regulators of glucose release. Overall, this work highlights the innate variability in cell wall traits of native willows and identifies potential genotypes that should be considered in future breeding and deployment strategies for Canadian bioenergy production. • Extensive assessment of 11 cell wall traits in Salix famelica and Salix eriocephala. • Significant interspecific variation in cell wall composition and wood ultrastructure. • Alkali pretreatment outperformed acid pretreatment in saccharification potential. • Glucose release was strongly impacted by lignin content and composition. • Saccharification potential was largely unaffected by wood ultrastructure. [ABSTRACT FROM AUTHOR]