NUTRIENT ACCUMULATION IN VEGETATION FOLLOWING CONVENTIONAL AND WHOLE-TREE HARVEST OF SITKA SPRUCE PLANTATIONS IN NORTH WALES

The role of regrowing vegetation in buffering nutrient losses following whole-tree and conventional harvest of Sitka spruce was examined at Beddgelert Forest in North Wales. Biomass and nutrient accumulation were about twice as rapid on the whole-tree (WH) than the conventional harvest (CH) plots, apparently because logging residue shaded the ground on the CH plots. This result probably helps to explain much higher leaching of nutrients from the root zone on the CH than the WH plots. However, the differences in nutrient accumulation in regrowing vegetation between WH and CH plots were much smaller than the differences (in the opposite direction) in nutrient removal of forest products. Thus, higher nutrient accumulation in regrowing vegetation following WH compared with CH may partly counteract leaching losses during the first few years but this effect is clearly outweighed by the higher nutrient removal in forest products in WH.