LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PLENARY SESSION 2: METHODOLOGICAL CHALLENGES FOR ANIMAL PRODUCTION SYSTEMS8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Table 9. Illustrative description of the livestock ecosystem services linear programming model. Columns
represent levels of activities and rows represent constraints on those activities. For illustration these have
been collapsed into a single description (e.g., sheep systems are actually 63 columns, with activities such as
hill, upland and lowland ewes, and organic flocks). Similarly rows have been collapsed into ‘Emissions’,
which includes rows for individual emissions such as greenhouse gases, nitrate leaching and pesticides.
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Sheep systems
Pig systems
Beef systems
Chicken
systems
Egg systems
Dairy systemsArablewell-suitedArablemoderateArablemarginal
Objective (services) = P+R+C
Provisioning + + + + + + + + + + = P
Regulating + = R
Cultural + + + + + + + + + + -ve = C
Constraint
Production 1 1 1 1 1 1 = Demand
Arable land + + + + + + 1 = L
Grassland + + + + + + 1 1 1 1 = L
Hill land + + 1 = L
Emissions + + + + + + + + + -1 = 0
Labour + + + + + + + + + -1 = 0
Intra-system + + + + + + = 0
Inter-system 1 -ve = 0
Land types + + + + + + < L
Notes: + denotes positive coefficients, -ve denotes negative coefficients, +/-1 denotes unit coefficients, L denotes limits/constraints
on land and soil types
The objective function to be maximised is the sum of the various ecosystem services, which have been
converted to a common monetary (£) valuation system (P+R+C). This comprises positive monetary values
for livestock production and arable production, negative values for emissions, and positive values for cultural
services and employment generation (columns, Table 1). Cultural services include landscape, biodiversity
and recreation benefits services considered jointly in terms of a value of willingness to pay that varies by
land use. In the main analyses, we consider employment as a benefit and value it as the minimum wage. The
relations between activities and constraints (columns and rows, respectively, Table 1) are defined by an array
of technical coefficients, showing, for example, farm labour requirements of a tonne of beef or nitrate emissions
generated in the production of a tonne of meat on a particular type of land.
The systems-based LCA approach also enabled the implications of a range of alternative future scenarios
to be explored, including a 25% reduction in livestock production balanced by plant commodities, a shift
from red to white meat and arable substitution of the livestock sector. The model maximises the weighted net
benefit of the ecosystems services generated from each of the livestock sectors.
3. Results
Estimates of the value of ecosystem services, classified into provisioning, regulating and cultural services
were first obtained for the BAU scenario. This involved an allocation of land, both grassland and the arable
area required to provide non-grass feeds, to meet current demand for livestock products. The proportional
distribution of grassland and arable land for each 5x5 km square in England and Wales was estimated using
spatially interpolated 2004 Agricultural Census data (Edine, 2010). These confirm the greater incidence of
grassland and livestock production in the northern and western regions, associated with sheep, dairy, and
beef systems, although it is worth noting the significant production of pigs and poultry in the eastern part of
England. Grasslands were divided into lowland (