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

Silviu O Petrovan,Philip M Wheeler,Emma Yapp,John Dixie

doi:10.1007/s10344-017-1106-5

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.

Highlights

The rapid expansion of bioenergy crops and their relationship with farmland biodiversity in temperate climates have generated increasing interest and concern in recent years (Semere and Slater 2007; Pedroli et al 2013; Everaars et al 2014; Bourke et al 2014), given that biodiversity in such areas has declined markedly for decades due to agricultural intensification (Benton et al 2002; Tscharntke et al 2012)
While there is a general scarcity of data in this area, previous research on ecological effects of such crops has focused on birds, plants or invertebrates and remarkably little is currently known about the impacts of bioenergy crops on mammals, medium- to large-bodied species
While previous studies on the effects of biomass energy crops on biodiversity have looked at patterns in occurrence of multiple species, there have been no detailed investigations of the mechanisms by which species interact with these crops, something which is vital if crop production and biodiversity conservation are to be managed jointly

Summary

Introduction

The rapid expansion of bioenergy crops and their relationship with farmland biodiversity in temperate climates have generated increasing interest and concern in recent years (Semere and Slater 2007; Pedroli et al 2013; Everaars et al 2014; Bourke et al 2014), given that biodiversity in such areas has declined markedly for decades due to agricultural intensification (Benton et al 2002; Tscharntke et al 2012). The theoretical potential for total area occupied by biomass energy crops (principally Miscanthus and short-rotation coppice willow) of between 0.72 and 2.80 Mha in the UK alone (DECC 2012) is sufficient to generate significant impacts and land-use conflicts with both food production and farmland biodiversity. While there is a general scarcity of data in this area, previous research on ecological effects of such crops has focused on birds, plants or invertebrates and remarkably little is currently known about the impacts of bioenergy crops on mammals, medium- to large-bodied species This is despite the fact that medium and large mammals in Europe include both threatened species of conservation concern and abundant species such as deer, which can have significant economic and biodiversity effects (Côté et al 2004). While previous studies on the effects of biomass energy crops on biodiversity have looked at patterns in occurrence of multiple species, there have been no detailed investigations of the mechanisms by which species interact with these crops, something which is vital if crop production and biodiversity conservation are to be managed jointly

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