How sustainable is stump and root harvesting for bioenergy production?

Extraction of tree stumps and roots is commonplace in the Brecklands as a measure to reduce the risk of tree disease, but its introduction into the British Uplands during the 2000s raised concerns that soil disturbance during extraction could be environmentally detrimental. However, such concerns were largely based on evidence from overseas because there was little or no information under British conditions. A project was initiated to study the nature of soil disturbance resulting from British stump harvesting in 2010, supported by the Forestry Commission, University of Stirling and UPM-Tilhill (now Tillhill Forestry). Andy Moffat was one of three supervisors for this project but its successful outcome was very largely due to the energy and intellect of Dr Jeff Collison, the main investigator. The study showed that stump harvesting can cause disturbance up to five times that measured under trench mounding, a conventional method of site preparation. Such disturbance may be unacceptable in peaty soils where oxidation of soil carbon may counteract environmental benefits from using woody biomass rather than fossil fuels to generate energy. The results of the research have now been published by Scottish Forestry, the journal of the Royal Scottish Forestry Society. To access the paper, click HERE.