Habitat type plays a greater role than livestock grazing in structuring shrubsteppe plant-pollinator communities

Published source details Elwell S.L., Griswold T. & Elle E. (2016) Habitat type plays a greater role than livestock grazing in structuring shrubsteppe plant-pollinator communities. Journal of Insect Conservation, 20, 515-525.
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This study is summarised as evidence for the following.

	Action	Category
	Employ areas of semi-natural habitat for rough grazing (includes salt marsh, lowland heath, bog, fen) Action Link

Employ areas of semi-natural habitat for rough grazing (includes salt marsh, lowland heath, bog, fen)

A replicated, paired, site comparison study in 2010 in eight shrubsteppe sites in British Columbia, Canada (Elwell et al. 2016) found that grazed shrubland did not support a higher abundance, species richness or diversity of pollinators (including butterflies) than ungrazed shrubland. On grazed shrubland, the total abundance (469–1,188 individuals), species richness (82–124 species) and diversity (data presented as model results) of pollinators, including butterflies, were all similar to ungrazed shrubland (abundance: 576–925 individuals; richness: 86–113 species). Four pairs of sites (20–1,850 ha), similar in topography and vegetation, were selected. Within each pair, one site was grazed with cattle for 4–6 weeks between April and June annually or biannually, at 14–160 cows/ha/month, while the other site had been ungrazed for 6–40 years. From April–July 2010, pollinating insects were sampled eight times (bi-weekly) by setting 30 yellow, white and blue 12-oz pan-traps for 8.5 hours at 3-m intervals diagonally across a 1-ha plot at each site. Paired sites were always sampled on the same day.

(Summarised by: Andrew Bladon)