Impacts on biodiversity
Impacts on biodiversity are shown in Figure 12.5 to vary substantially between regions and policy scenarios, and to differ substantially from the policy impacts on mosaic. For Jonkoping, REFORM had little impact on biodiversity, unlike the impact on mosaic. This result is attributable to the similarity, as described above, of the GAEC obligation and agri-environmental schemes for semi-natural grassland. Despite a significant decline in modelled beef output under REFORM due to decoupling of headage payments, farm agents reorganised livestock holdings to minimise the cost of landscape management by switching to sheep from cattle. As indicated above, only 49% of the semi-natural grassland area is preserved in Jonkoping under the BOND scenario (i.e. in absence of the GAEC obligation). Additional simulations indicate that this proportion would fall towards zero if agri-environmental payments were also eliminated. In this sense, existing Pillar 2 payments act to buffer the landscape impacts of decoupling, but not entirely. Note, however, that the substantial decline in mosaic (-36%) and land abandonment (41%) in Jonkoping under BOND does not translate into a proportional reduction in biodiversity; a result of the diminishing marginal productivity of habitat. As shown in Figure 12.5, biodiversity falls by only 15% according to our indicator (but this is potentially serious as it represents the loss of around 26 red-listed species).
Impacts on biodiversity were similar across all scenarios for Vasterbotten because coupled Pillar 2 national support, which remains unchanged in all scenarios, buffers the impacts of decoupling on production. Since arable grassland is the dominant habitat in this region, the reduction in area under BOND (-16 %) has only a marginal impact on biodiversity (because the marginal biodiversity value of arable grassland in this region is low).
Figure 12.5. Relative change in biodiversity in 2013 compared to 2004
Percentage change in number of species ? AGENDA ? REFORM ? BOND
N/A: Not applicable.
Source: Brady et al. (2009).
Reduced biodiversity in the REFORM and BOND scenarios for Vysocina might seem inconsistent with the corresponding improvements in mosaic shown in Figure 12.4, since land use diversity is generally supposed to be important for maintaining biodiversity. The primary driver of biodiversity conservation in this region is the area of pasture. Pasture is not only the ecologically most productive habitat but it is also scarce, which translates into high marginal biodiversity value according to the species-area relationship. As such, even a small reduction in the area of pasture causes a relatively large reduction in biodiversity. In terms of mosaic, the reduction in pasture area is compensated for by increased diversity of arable crops. AGENDA (i.e. pre-accession policy) results in increased biodiversity because it favours suckler/extensive beef production (due to lower payment levels) and hence a greater area of pasture. Perhaps surprisingly, the BOND scenario is better for biodiversity than REFORM. This result is due to two complementary effects: an increase in the relative profitability of suckler beef production which requires pasture, and the EUR 110/ha agri-environmental payment to pasture/grassland which raises the relative profitability of this land use in BOND. Hence pasture area and biodiversity decreased relatively less compared to REFORM, which is more favourable to intensive beef production.
The modelled losses in biodiversity in Vysocina illustrate the problem of having a minimum land management obligation when biodiversity is dependent on preserving specific habitats. Even though agricultural activity is maintained, important habitats may still be lost, denying the general proposition of joint production between farming and the environment.
For Calabria, both decoupling scenarios result in significant reductions in the area of managed olive plantation. However, due to uncertainty about the importance of agriculture for biodiversity conservation in this region, we do not present a biodiversity index (i.e. we have not been able to investigate the ecological consequences of ceasing to manage perennial habitat). A similar effect did not occur for Marche because of the relatively small area of olives. Reduced mosaic value for Marche under BOND did not translate into lower biodiversity value because different arable crops in the region were assumed to have equivalent habitat value (i.e. can substitute for each other). Since the total area of arable habitat remained unaffected by decoupling, so did biodiversity value according to our indicator.