  Financial incentives are provided by governments to encourage the plantation
of new woodland to increase habitat, biodiversity, carbon sequestration, and
other economic benefits for landowners. Whilst these are largely positive
effects, it is worth considering that greater biodiversity and presence of
wildlife species in proximity to agricultural holdings may pose a risk of
disease transmission between wildlife and livestock. Wildlife transmission and
the provision of a reservoir for infectious disease is particularly important
in the transmission dynamics of bovine tuberculosis.
  In this paper we develop an economic model for changing land use due to
forestry subsidies. We use this asses the impact on wild deer populations in
the newly created woodland areas and the emergent infectious disease risk
arising from the proximity of new and existing wild deer populations and
existing cattle holdings.
  We consider an area in the South-West of Scotland, having existing woodland,
deer populations, and extensive and diverse cattle farm holdings. In this area
we find that, with a varying level of subsidy and plausible new woodland
creation, the contact risk between areas of wild deer and cattle increases
between 26% and 35% over the contact risk present with zero subsidy.
  This model provides a foundation for extending to larger regions and for
examining potential risk mitigation strategies, for example the targeting of
subsidy in low risk areas or provisioning for buffer zones between woodland and
agricultural holdings.
