Afforestation projects are viewed as potentially effective measures for carbon sequestration and therefore climate change mitigation. Increasing demands for bioenergy products also require land for woodland plantations. Much of the land in temperate regions suitable for afforestation is used for agriculture and consequently afforestation of farmland is frequently proposed. Land owners are commonly reluctant to sacrifice fertile land for purposes other than food and feed production. In Scotland's uplands, grazed pastures are a common land use that could be put under pressure by demands for woodland planting. This chapter explores how farm woodland planting for carbon sequestration and biofuel production affects livestock output. Sheep productivity, soil carbon and tree biomass data from a hill farm in Aberdeenshire, Scotland, are used to estimate the carbon balance and agricultural output of farm woodland plots and silvopastoral systems. The conceptual ideas of trade-off curves are illustrated with the example of 'trees versus sheep'. Planting trees on pastureland can have varying impact on sheep depending on density and planting system. Within the concepts of trade-offs and synergies, it is furthermore discussed whether agroforestry systems such as silvopasture can ameliorate trade-offs between woodland and agriculture by enhancing agricultural productivity while also providing carbon benefits. The concepts presented show that there is great potential for integrating agriculture and forestry to achieve environmental benefits without compromising productivity.