Action: Retain existing in-field trees
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of retaining existing in-field trees on bat populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.
Single or scattered trees, particularly mature or veteran trees, may provide important roosting and foraging habitat for bats in open agricultural landscapes. Two studies in Australia found greater total bat activity and more bat species over pastures or paddocks with scattered trees than open pastures without trees (Lumsden & Bennett 2005, Fischer et al. 2010). A study in Sweden found that tree density (up to 120–130 trees/ha) had a positive effect on total bat activity, activity of cluttered and edge habitat adapted bat species, foraging activity and species richness in wood-pastures (Wood et al. 2017).
To be included as evidence for this intervention, studies must have monitored a comparison, i.e. compared areas where existing in-field trees have been retained with areas where they have been removed. There must have been an active decision (i.e. intervention) to retain the in-field trees and the study must state when the intervention was carried out.
For studies that may carry out this intervention alongside other interventions to benefit bats on farmland, see ‘Introduce agri-environment schemes’. For studies that relate to retaining remnant forest or woodland, see ‘Retain remnant forest or woodland on agricultural land’.
Lumsden L.F. & Bennett A.F. (2005) Scattered trees in rural landscapes: foraging habitat for insectivorous bats in south-eastern Australia. Biological Conservation, 122, 205–222.
Fischer J., Stott J. & Law B.S. (2010) The disproportionate value of scattered trees. Biological Conservation, 143, 1564–1567.
Wood H., Lindborg R. & Jakobsson S. (2017) European Union tree density limits do not reflect bat diversity in wood-pastures. Biological Conservation, 210, 60–71.