Comparison of biomass production in coppice and single stem woodland management systems on an imperfectly drained gley soil in central Scotland

A comparison of biomass production from single stems and coppice has been c arried out in Lanarkshire, Scotland. The site comprises a noncalcareous gle y at 210 m above sea level and has a cool, temperate climate with 1100 mm p recipitation. Red alder (Alnus rubra Bong,) and balsam spire poplar (Populus balsamifera var. Michauxii (Henry) x Populus trichocarpa var. Hastata (Dode) Farwell) w ere grown at 1.0 m spacing as coppice or single stems and at 1.5 m spacing as single stems only. Common osier willow (Salix viminalis L.) was also gro wn as coppice at 1.0 m spacing. Trees were planted in May 1989 and the copp ice was cut back in the winter following planting. High mortality occurred in the red alder following coppicing and this reduced the stocking by 50%. Biomass production ranged from 2.0 to 8.4 Mg ha(-1) y(-1) in 1992 and this had increased to between 6.5 and 10.7 Mg ha(-1) y(-1) by 1995. Production f rom coppice and single stems was similar in 1992. By 1995, coppice producti on was 28% less than single stems due, in part, to a decrease in willow pro ductivity from 1992 onwards. Although individual trees were larger at wider spacing, productivity per hectare was reduced. Analysis showed that a single regression model using basal area explained 9 1% of the variation in woody biomass per tree for all treatments and for al l years. (C) 1999 Elsevier Science Ltd. All rights reserved.