Individual study: New tools to boost butterfly habitat quality in existing grass buffer strips
Blake R., Woodcock B., Westbury D., Sutton P. & Potts S. (2011) New tools to boost butterfly habitat quality in existing grass buffer strips. Journal of Insect Conservation, 15, 221-232
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Plant grass buffer strips/margins around arable or pasture fields
A replicated, controlled study in the summers of 2008-2009 in Berkshire, UK (Blake et al. 2011) found that butterfly (Lepidoptera) abundance, species richness and diversity were positively associated with the number of sown wildflower species in existing grass buffer strips. Butterfly species richness was higher in plots that had received a combined treatment of scarification and grass-specific herbicide application compared with single treatment and control plots. Butterfly abundance and diversity were higher in plots that were both scarified and treated with grass-specific herbicide than single treatment, but not control plots. Sown wildflower cover and species richness was higher in the combined treatment plots in both years, and there was a significant increase in wildflower cover from 2008 to 2009. In both years, species richness of unsown wildflowers (annuals, perennials and in total) was higher in the combined scarification/grass-specific herbicide treatments. It was also higher in scarification-only than in grass-specific herbicide-only and control plots, but it decreased in scarified plots from 2008 to 2009. Six metre-wide grass buffer strips were created on two arable farms in 2004 and managed under an Entry Level Stewardship agreement from 2005. Four treatments were randomly established within each of three replicate blocks/site in early spring 2008: scarification, selective grass-specific herbicide application, scarification and selective grass-specific herbicide, control. Scarification was always followed by sowing a wildflower seed mixture. All plots were cut in autumn and cuttings left in place. In both years vegetation was assessed once in June, in ten randomly placed 0.25 m2 quadrats within each treatment plot avoiding the edges. Percentage cover of all plant species was estimated on an eight point scale. Abundance, diversity and species richness of adult butterflies was recorded during standard transect walks along the centre of each treatment plot (25 x 4 m). Each plot was sampled eight times/year between May and September.