Bioenergy crops and farmland biodiversity: benefits and limitations are scale-dependant for a declining mammal, the brown hare

Abstract

Biomass energy crops are prompting major land-use changes in agricultural and marginal land in an effort to reduce dependency on fossil fuels. Miscanthus × giganteus , a perennial giant grass, is one of the main such crops in Europe but few studies exist of its interaction with farmland wildlife, particularly mammals. Understanding ecological impacts of bioenergy planting schemes is vital for mitigating potential negative effects on already declining farmland biodiversity and for maximising any benefits from these low-management, structurally diverse crops. We assessed in a mixed farming area in the UK the impact of Miscanthus crops on the brown hare ( Lepus europaeus ), a widespread but declining farmland species of conservation concern. We intensively radio-tracked hares in Miscanthus blocks of contrasting size and analysed hare diet for evidence of the consumption of Miscanthus . Home ranges differed starkly averaging 10.5 versus 49.6 ha in the small and the large Miscanthus blocks, respectively. Despite entirely avoiding the crop as food, hares appeared able to exist and even thrive in areas planted with Miscanthus though their populations may be significantly limited by reduced food availability and increased energy use where dense Miscanthus is planted over a wide area. As a component of a mixed farming landscape, Miscanthus may provide biodiversity benefits by increasing spatial heterogeneity and refuge areas for declining farmland species like brown hares but any effect is likely to be strongly scale-dependant.