Individual study: Effect of sward type and management on butterfly numbers in the uplands
Fraser M.D., Evans J.G., Davies D.W.R. & Vale J.E. (2008) Effect of sward type and management on butterfly numbers in the uplands. Aspects of Applied Biology, 85, 15-18
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Employ areas of semi-natural habitat for rough grazing (includes salt marsh, lowland heath, bog, fen)
A replicated trial in 2005-2007 of cattle grazing on six experimental plots of semi-natural upland grassland dominated by purple moor grass Molinia caerulea in the UK (Fraser et al. 2008) found more butterfly (Lepidoptera) species and significantly more individual butterflies than on permanently or partially grazed plots of improved pasture. Between 15 and 17 butterfly species (905-1938 individual butterflies) were recorded on the semi-natural plots in each year, compared to 7-11 species (42-156 butterflies) on ten continually grazed and 5-10 species (21-67 butterflies) on ten partially grazed plots of improved pasture. The semi-natural plots were grazed from June to September, while the partially grazed improved plots were grazed in spring and autumn, but had livestock excluded from May to September and one silage cut taken. Butterfly transect counts were conducted weekly between mid-April and mid-September in 2005, 2006 and 2007.
Reduce grazing intensity on grassland (including seasonal removal of livestock)
A replicated trial of two intensities of cattle grazing on permanent improved grassland plots in the UK (Fraser et al. 2008) found no strong difference in numbers of butterflies (Lepidoptera) between partially grazed and permanently grazed plots. On average there were 7-11 butterfly species (42-156 individuals) on permanently grazed plots and 5-10 butterfly species (21-67 individuals) on partially grazed plots of improved pasture. Ten experimental plots of improved perennial rye grass Lolium perenne/white clover Trifolium repens were grazed throughout the year by livestock. Ten similar plots were grazed in spring and autumn, but had livestock excluded from May to September and one silage cut taken. No location is given for the experiment. Butterfly transect counts were conducted weekly between mid-April and mid-September in 2005, 2006 and 2007.