Background information and definitions
Scrub may consist of vegetation dominated by bushes, shrubs and tree saplings (Mortimer et al. 2000). Scrub on farmland can add habitat complexity and heterogeneity. However, if scrub dominates non-productive land on farms it may lead to declines in species that require grassland and other farmland habitats. Scrub control may include cutting, grazing or herbicide application (Mortimer et al. 2000).
Mortimer S.R., Turner A.J., Brown V.K., Fuller R.J., Good J.E.G., Bell S.A. Stevens P.A., Norris D., Bayfield N. & Ward L.K. (2000) The nature conservation value of scrub in Britain. JNCC Report 308.
Supporting evidence from individual studies
A replicated site comparison study from 2004 to 2008 on agricultural sites across England (Ewald et al. 2010) investigated the impact of scrub control on grey partridge Perdix perdix. There was a negative relationship between a combined intervention (scrub control, rough grazing and the restoration of various semi-natural habitats) and the ratio of young to old partridges in 2008. The study does not distinguish between the individual impacts of scrub control, rough grazing and the restoration of various semi-natural habitats. Spring and autumn counts of grey partridge were made at 1031 sites across England as part of the Partridge Count Scheme.