A management regime for hybrid aspen stands combining conventional forestry techniques with early biomass harvests to exploit their rapid early growth

A management regime that combines early harvests and conventional forestry techniques is proposed for hardwood stands in northern environments and is illustrated by the potential use of hybrid aspen (Populus tremuloides Michx. × Populus tremula L.). The high early biomass production rates of hardwoods could be exploited by corridor cleaning and use of the material harvested for biofuels, while the remaining stand could be treated with ordinary forestry measures to produce pulpwood and logs. Regenerating hybrid aspen rapidly produces a large number of suckers. In this study, 76,000 suckers ha−1 on average was found at a site in southern Sweden 2 years after clear felling. After 4 years 38 tonnes of dry matter ha−1 could be extracted, corresponding to 9.5 tonnes ha−1 year−1. However, areas, which were corridor-cleaned already 2 years after felling produced, in total significantly less biomass (6.8–6.9 tonnes ha−1 year−1) in the 4-year post-felling period. The high early rates of biomass production suggest that the combined forestry concept has interesting potential, but the effects of corridor cleaning and biomass removal on the future growth and quality of the stand should be examined in further studies before it is practiced on a commercial scale.