Compared to slower growing trees like spruces, hybrid poplars and selected aspens grown in these plantations are ready for harvest in less than 20 years. The technology development specialists established this a mixed wood crop to evaluate how short-rotation or fast-growing tree crops (123 to 17 years to maturity) could sustain and expand the bioenergy sector. High-yield crops like these are crucial for the sector, which relies on woody biomass to produce clean energy.