www.tsec-biosys.ac.uk The UK’s energy crop potential in current and future climates Gail Taylor University of Southampto

1. www.tsec-biosys.ac.uk The UK’s energy crop potential in current and future climates Gail Taylor University of Southampton University of Aberdeen, Forest Research, Imperial College, Scottish Agricultural College, Rothamsted Research The Royal Society, London: 28th July 2009

2. Strategic importance of bioenergy remains high – UK Renewable Energy Strategy, 2009 • UK Renewable Energy Strategy – July 2009 • Biomass for heat • Sustainable biofuels • Biomass for electricity • Better management of woodlands • Increased growth of dedicated energy crops • New crops for bioenergy

3. UK Biomass supply? • Food crops • Oil seed rape – 800,000 ha • Wheat – 2 million ha • Woodland and woody biomass resource • Could supply 2-20 million tonnes annually • Waste • 2-10 million tonnes • Dedicated energy crops – grasses and trees • Currently approximately 15,000 ha – 150,000 tonnes • Could supply 1-10 million tonnes biomass for energy

4. Aims of TSEC-BIOSYS • Quantify biomass for bioenergy supply at regional scale • Develop spatial and temporal supply maps • Cost-based supply analysis • Map environmental constraints – GHG, water, biodiversity • Develop process based models – test new genotypes and assess impacts of climate change UKCIP2003/09 scenarios

5. Why focus on 2G crops? • Improved energy balance, GHG balance compared to food crops- sustainable • Ability to be grown on wide categories of agricultural and non-agricultural (abandoned and marginal) land • Very limited evidence base compared to food crops – models, supply, costs, genotypes, etc

6. Approach – integrate disparate data • Used available datasets, alongside those for soil, temperature, water availability etc., to develop empirical yield maps – correlations for current conditions -miscanthus -SRC • Use available datasets to develop predictive process-based models – able to make statements about future climates?

7. How can yield maps be useful? Growers and planners Bioenergy developers/economic analysis Assess environmental impacts biodiversity GHG SRC yield from Aylott et al 2008, New Phytologist. Water

8. Empirical Yield Maps Forest Research 49 site trial (DEFRA) • Extensive database • Good coverage of UK climatic zones • Willow and poplar

9. Empirical model: Results • Models described 51-75% of yield variation • Willow yields were higher than poplar, particularly in the 2nd rotation • Spring/summer precipitation correlates highly with yield, indicating both species were affected most by water supply

10. Trichobel P Jorunn W Q83 We have produced extensive yield map datasets for SRC willow and poplar

11. Empirical yield model for MiscanthusRichter, G. M. et al. (2008) Soil Use and Management24 (3), 235

12. Land use trade-offs - Methods • Accounted for land quality by Agricultural Land Classification (ALC) grade and currently grown food crops • Incorporated a range of constraints on energy crops • environmental, physical • agricultural, agronomic • socio-economic • Used revised Miscanthus yield map for England and display on ALC 3, 4 land only Lovett, A. A. et al., BioEnergy Research (2009)

13. Regional distribution of Miscanthus yield • Regional contrasts occur in the importance of different constraints • Areas with highest yields co-locate with important food producing areas • On average, Miscanthus yields 12.5 odt ha-1 on suitable land(ALC 3 or 4) • Between 10 and 40% are likely to be below an economic threshold of 9 t/ha Lovett, A. A. et al., BioEnergy Research (in press)

14. Excluded areas: • Areas of Outstanding Natural Beauty • National Park • Forest Park • Planted Ancient Woodland Site • RSPB Reserve • Inland water, town and road • National Trust land • Lowland Heath/Bogs/Fens/Mire • Ancient woodland • Coastal sand dune • RAMSAR site • SSSI • Special Protected Area • Local or National Nature Reserve • Countryside Right of Way • Registered Common Land • Country Park • Listed building, World Heritage Site or Monument

15. Supply & Demand Modelling • Majority of land would yield between 10 - 14 t odm/ha/yr • Map based on annual costs of 20 - 60 £/odt • Preference map shows 4.4 Mha of Miscanthus and 6 Mha of SRC • This preference may change with better estimates (models) and varieties

16. Assessing the GHG mitigation potential of UK bioenergy crops • SRC and Miscanthus generally have better soil C balance than WW or OSR (i.e. they have lower net emissions or higher net sequestration) • Soil GHG emissions are highest in regions where Soil C is currently highest, e.g. Westerly regions, the fens. • So net balance clearly depends both on the bioenergy crop cultivated, and on the initial soil conditions (directly affected by previous land use).

17. GHG balance – also combined with LCA from Topic 3.2

18. What about climate change? • Predictive, process-based models are required • Process-based models also identify plant target traits for future breeding • Grass and tree models exist but they are not parameterized or validated for SRC and miscanthus

19. Process based modelling • Process-based models allow linkages between climate change scenarios and productivity to be investigated. • The forest productivity model, ForestGrowth1,2, has been parameterised for SRC using literature and field measurements3,4. • Outputs have been validated against site/species-specific data5. 1. (Evans et al., 2004), 2. (Deckmyn et al., 2004) 3. (Casella & Sinoquet, 2003), 4. (Gielen et al., 2003) 5. (Aylott et al., unpublished data)

20. Model overview ForestGrowth • Phase 2: Leaves are then added and if there is insufficient light, stem growth will occur • Phase 1: Storage carbon replenishes the existing canopy for 20 days • Phase 3: Carbon will be added to the pool of stored carbon – in preparation for the following years growth • Phase 4: Leaf fall occurs Phase 5: Dormancy

21. Process model – work in progress ForestGrowth Outputs • ForestGrowth has been parameterised for two poplar species (and soon for willow). • Preliminary evidence – 20% yield increase when temp, rainfall and CO2 modified to 2050 medium scenarios Productivity map of Populustrichocarpagenotype ‘trichobel’, second rotation

22. What about growers? • Drax & Wilton 10 • Eccleshall • Didcot • 150 respondents • 3 growing SRC Willow • 9 growing Miscanthus

23. TSEC BIOSYS Imperil College London

24. Key findings for policy makers from farmer attitudes • Significant non-financial barriers including security and stability of income from contracts • Simply increasing gross margin without tackling these barriers won’t bring about widespread adoption

25. Summary – key findings • We have developed empirical yield models for SRC willow, poplar and miscanthus and GIS-based maps – tools for stakeholders. Contribute to developing the energy landscape in the UK. • Made massive strides forward towards predictive yield modelling – parameterize and validate. • We have mapped GHG emissions for miscanthus and SRC – important outputs emerging • Identified the non-financial barriers to farmer uptake – How can we overcome them?

26. Thank you for your attention! www.tsec-biosys.ac.uk