Agriculture, bioenergy and ecosystem services: A British perspective

Background/Question/Methods

The UK has around 11 million ha of productive agricultural land, which is managed largely for food production. The mid-late 20th Century saw a trend for increased yields, specialisation and landscape homogenisation, driven by mechanisation, markets and policies. Self-sufficiency in indigenous foods has risen from less than 40% in the 1930s to over 70 %;  one third of the 150 million tonnes of biomass used in the UK is sourced from overseas. During the 1990s, greater priority was given to environmental issues. Some ecosystem services from UK Farmland have been improving, including climate regulation, air and water quality, while others such as biodiversity are in decline. Demands on the land are now increasing because of rapid rises in food prices (food production is increasing again), urban spread, and the policy requirements for increased bioenergy production. The UK now aims to obtain 15% of all its energy from renewables by 2020; this may require around 350,000 ha of domestically-grown perennial energy crops, compared with virtually zero in 2000, as well as 740,000 ha of crops for biofuels.  Such areas could be found if other sectors (e.g. livestock) were to be smaller.

Results/Conclusions

The impacts of greater levels of bioenergy crops on ecosystem services vary; the main impact of using arable crops (excluding crop wastes) is to increase pressure for indirect land use change, while the impacts of perennial crops on climate regulation and nutrient cycling depend on what is replaced. Short rotation coppice may also enhance biodiversity.

Bioenergy from arable crops is not a solution: a new plant to produce biofuel from wheat opened in 2009 and shut down in 2011 because of ‘depressed market conditions.’ Estimates of future production from perennial crops vary greatly according to constraints on land use change.

It may prove impossible to meet all future demands for ecosystem services in the UK under present projections. We need to better understand how ecosystem processes interact if we are to generate farmed landscapes that deliver food, energy and other ecosystem services in optimum ways. Public engagement is needed to establish priorities, values and mechanisms for ecosystem service delivery from Enclosed Farmland, not least because the full cost of these services may prove far greater than allowed for in current policies and markets.