Introduction to hedgerows and field margins

Abstract

This book is primarily about the ecology of hedgerows, but we have included ‘field margins’ in the title of the book because to understand what happens in hedgerows, it is necessary to consider the influences of the adjacent land use, and these are much more complex than when Ernie Pollard, Max Hooper and Norman Moore published their seminal work Hedges in 1974 (Pollard et al. 1974). Indeed, in many cases in order to understand what is happening at the local level, it is important to consider the wider landscape-scale issues. Since the publication of Hedges, compulsory set-aside has come and gone (at least in the EU; Daugbjerg & Swinbank 2011), several classes of pesticide have been developed and been superseded by others (Jeschke et al. 2011), farmland intensification has continued with continuing loss of hedgerows either through removal (Figure 1.1) or lack of management (Carey et al. 2009a), farmland wildlife has significantly declined (Stanton et al. 2018) and responses such as agri-environment schemes have been introduced in an attempt to stem the losses (Anonymous 2009). In addition, the biodiversity and wider value of hedgerows to farming and society have been increasingly recognised through the concept of ecosystem services (Reid et al. 2005). Hedgerows are given protection in a number of countries (Baudry et al. 2000), though such protection may be partial. In the UK, for example, whilst hedgerows are designated as priority habitat (JNCC 2011), they must exhibit specific characteristics to be eligible for protection, and protection is not available for certain types of hedgerow such as those surrounding curtilages (DOE 1997; Marrington 2010). This chapter briefly introduces readers to the different components of hedgerows and field margins and some important concepts. Succeeding chapters concentrate on particular issues; in some the emphasis is strictly on one component of the system (such as Chapter 3 on the management of hedges or Chapter 6 on softening 1