Quantifying the value of trees outside woods for promoting biodiversity on farmland

Abstract Within the farmed landscape, trees outside woods (TOWs), such as hedgerows, copses and scattered trees, provide a variety of benefits for wildlife and people, but these are not well understood or recognised. Many TOWs continue to be lost from the landscape. We used butterflies as a model group and explored patterns in their abundance and species richness in relation to the extent and type of TOWs, using data from the UK's Wider Countryside Butterfly Survey. We explored farmers' views of TOWs using an online survey. In general, the predictive power of the statistical models was not high, but some clear patterns emerged. Small woodlands were positively associated with overall butterfly abundance and species richness, especially in more arable landscapes. Higher numbers of ancient trees were associated with higher butterfly species richness. Hedgerows and woody strips had a positive effect on five of seven common species studied. As woodland increased in the landscape, up to a certain level, so did the abundance of meadow brown Maniola jurtina , speckled wood Parare aegeria , ringlet Aphantopus hyperantus and comma Polygonia c‐album . More ancient woodland in the landscape was associated with more P. aegeria and A. hyperantus butterflies. Farmers viewed TOWs as having a range of benefits, including value for wildlife and the landscape, helping combat climate change, improving soil health and reducing flooding. Time, expense and long‐term commitment dominated farmer concerns around TOWs. Management knowledge and practice tended to be more consistent for hedgerows than for other types of TOWs. Most respondents indicated they would like more information on managing TOWs. Practical implication. Heterogeneous farmed landscapes rich in hedgerows, small woodlands and ancient trees were associated with more abundant and species‐rich butterfly communities than landscapes with few of these features. There was clear recognition by farmers of the benefits of TOWs for farming and the environment. Farmers should be better supported to help deliver these benefits, financially and through knowledge exchange. The protection and restoration of TOWs on farmland should be an essential part of efforts to address the biodiversity and climate crises and at the forefront of farm‐scale and landscape‐scale initiatives.