Farm-scale ecological and economic impacts of agricultural change in the uplands
Recent decades have witnessed substantial losses of biodiversity in Europe, partly driven by the ecological changes associated with intensification of agricultural production. These changes have particularly affected avian (bird) diversity in marginal areas such as the uplands of the UK. Future trends for upland birds will likely be impacted by changes in agricultural support regimes, such as those currently envisaged in on-going reforms of the Common Agricultural Policy. We developed integrated ecological-economic models, using seven different indicators of biodiversity based on avian species richness and individual bird densities. The models represent six different types of farms which are typical for the UK uplands, and were used to assess the outcomes of different agricultural futures. Our results show that the impacts of these future agricultural scenarios on farm incomes, land use and biodiversity are very diverse across policy scenarios and farm types. Moreover, each policy scenario produces un-equal distributions of farm income changes and gains and losses in alternative biodiversity indicators. This shows that generalisations of the effects of policy and pricing changes on farm incomes, land uses and biodiversity can be misleading. Our results also suggest that a focus on umbrella species or biodiversity indicators (such as total species richness) can miss important compositional effects.