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The paper presents a model system, which consists of a partial equilibrium model and process-based terrestrial biogeochemistry models, to determine the optimal distributions of both Miscanthus ( Miscanthus × giganteus) and short rotation coppice willow ( SRC) ( Salix. viminalis L. x S. viminalis var Joruun) in Great Britain ( GB), as well as their potential contribution to meet heat and electricity demand in GB. Results show that the potential contribution of Miscanthus and SRC to heat and electricity demand is significant. Without considering farm-scale economic constraints, Miscanthus and SRC could generate, in an economically competitive way compared with other energy generation costs, 224 800 GWh yr−1 heat and 112 500 GWh yr−1 electricity, with 8 Mha of available land under Miscanthus and SRC, accounting for 66% of total heat demand and 62% of total electricity demand respectively. Given the pattern of heat and electricity demand, and the relative yields of Miscanthus and SRC in different parts of GB, Miscanthus is mainly favoured in the Midlands and areas in the South of GB, whereas SRC is favoured in Scotland, the Midlands and areas in the South of GB. [ABSTRACT FROM AUTHOR]

This paper defines the potentially available land for perennial energy crops across Great Britain as the first component of a broader appraisal undertaken by the 'Spatial Modelling of Bioenergy in Great Britain to 2050' project. Combining data on seven primary constraints in a GIS reduced the available area to just over 9 M ha (40% of GB). Adding other restrictions based on land cover naturalness scores to represent landscape considerations resulted in a final area of 8.5 M ha (37% of GB). This distribution was compared with the locations of Miscanthus and SRC willow established under the English Energy Crop Scheme during 2001-2011 and it was found that 83% of the planting fell within the defined available land. Such a correspondence provides confidence that the factors considered in the analysis were broadly consistent with previous planting decisions. [ABSTRACT FROM AUTHOR]

Land-use change can have significant impacts on soil and aboveground carbon (C) stocks and there is a clear need to identify sustainable land uses which maximize C mitigation potential. Land-use transitions from agricultural to bioenergy crops are increasingly common in Europe with one option being Short Rotation Forestry ( SRF). Research on the impact on C stocks of the establishment of SRF is limited, but given the potential for this bioenergy crop in temperate climates, there is an evident knowledge gap. Here, we examine changes in soil C stock following the establishment of SRF using combined short (30 cm depth) and deep (1 m depth) soil cores at 11 sites representing 29 transitions from agriculture to SRF. We compare the effects of tree species including 9 coniferous, 16 broadleaved and 4 Eucalyptus transitions. SRF aboveground and root biomass were also estimated in 15 of the transitions using tree mensuration data allowing assessments of changes in total ecosystem C stock. Planting coniferous SRF, compared to broadleaved and Eucalyptus SRF, resulted in greater accumulation of litter and overall increased soil C stock relative to agricultural controls. Though broadleaved SRF had no overall effect on soil C stock, it showed the most variable response suggesting species-specific effects and interactions with soil types. While Eucalyptus transitions induced a reduction in soil C stocks, this was not significant unless considered on a soil mass basis. Given the relatively young age and limited number of Eucalyptus plantations, it is not possible to say whether this reduction will persist in older stands. Combining estimates of C stocks from different ecosystem components (e.g., soil, aboveground biomass) reinforced the accumulation of C under coniferous SRF, and indicates generally positive effects of SRF on whole-ecosystem C. These results fill an important knowledge gap and provide data for modelling of future scenarios of LUC. [ABSTRACT FROM AUTHOR]

To date, most Miscanthus trials and commercial fields have been planted on arable land. Energy crops will need to be grown more on lower grade lands unsuitable for arable crops. Grasslands represent a major land resource for energy crops. In grasslands, where soil organic carbon ( SOC) levels can be high, there have been concerns that the carbon mitigation benefits of bioenergy from Miscanthus could be offset by losses in SOC associated with land use change. At a site in Wales (UK), we quantified the relatively short-term impacts (6 years) of four novel Miscanthus hybrids and Miscanthus × giganteus on SOC in improved grassland. After 6 years, using stable carbon isotope ratios (13C/12C), the amount of Miscanthus derived C (C4) in total SOC was considerable (ca. 12%) and positively correlated to belowground biomass of different hybrids. Nevertheless, significant changes in SOC stocks (0-30 cm) were not detected as C4 Miscanthus carbon replaced the initial C3 grassland carbon; however, initial SOC decreased more in the presence of higher belowground biomass. We ascribed this apparently contradictory result to the rhizosphere priming effect triggered by easily available C sources. Observed changes in SOC partitioning were modelled using the RothC soil carbon turnover model and projected for 20 years showing that there is no significant change in SOC throughout the anticipated life of a Miscanthus crop. We interpret our observations to mean that the new labile C from Miscanthus has replaced the labile C from the grassland and, therefore, planting Miscanthus causes an insignificant change in soil organic carbon. The overall C mitigation benefit is therefore not decreased by depletion of soil C and is due to substitution of fossil fuel by the aboveground biomass, in this instance 73-108 Mg C ha−1 for the lowest and highest yielding hybrids, respectively, after 6 years. [ABSTRACT FROM AUTHOR]

Maps of energy demand from buildings in Great Britain have been created at 1 km square resolution. They reveal the spatial variation of demand for heat and electricity, of importance for energy distribution studies and particularly for bioenergy research given the significant distance-based restrictions on the viability of bioenergy crops. Maps representing the spatial variation of energy demand for the year 2009 were created using publicly available sub-national gas and electricity consumption data. A new statistical model based on census data was used to increase the spatial resolution. The energy demand was split into thermal energy (the heat energy required for space heating and hot water) and electricity used for purposes other than heating (nonheating electricity or NHE) and was determined separately for the domestic and nondomestic sectors. 'Scenario factors,' representing the fractional change at national level in the demand for heat and NHE, were derived from scenarios constructed by UKERC. These scenarios represent a range of pathways from the present day to 2050. The present work focused on the two cases of greatest relevance, the 'low carbon' and 'additional policies' scenarios, and factors for both were derived, for the demand types described, for every 5 years between 2000 and 2050. Approximately, future spatial energy demands can be obtained by applying the scenario factors to the base mapping data for 2009. [ABSTRACT FROM AUTHOR]