The effect of organic farming on butterfly diversity depends on landscape context

Published source details Rundlöf M. & Smith H.G. (2006) The effect of organic farming on butterfly diversity depends on landscape context. Journal of Applied Ecology, 43, 1121-1127.
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This study is summarised as evidence for the following.

	Action	Category
	Convert to organic farming Action Link
	Reduce field size (or maintain small fields) Action Link
	Increase the proportion of natural or semi‐natural habitat in the farmed landscape Action Link
	Pay farmers to cover the costs of conservation measures (as in agri-environment schemes or conservation incentives) Action Link

Convert to organic farming

A replicated, paired, site comparison study in 2003–2004 on 24 arable farms in Scania, Sweden (Rundlof & Smith 2006) found that organic farms had a higher abundance and species richness of butterflies and burnet moths than conventional farms in intensively farmed but not more diverse landscapes. In intensively farmed landscapes, both the abundance (1.7 individuals/50 m) and species richness (0.9 species/50 m) of butterflies and burnet moths on organic farms were higher than on conventional farms (abundance: 0.4 individuals/50 m; richness: 0.3 species/50 m). However, in more diverse landscapes, the abundance (4.5 individuals/50 m) and species richness (1.6 species/50 m) of butterflies and burnet moths on organic farms were not significantly different from conventional farms (abundance: 3.6 individuals/50 m; richness: 1.4 species/50 m). Twelve arable farms with >50% of land under EU-subsidized organic management in 2002 and 12 conventional farms of similar size, crop type and landscape features, were selected. Farm pairs were 3–8 km apart. Six pairs of farms were in diverse landscapes (15% arable land, 19% pasture, small fields), and six pairs were in intensively farmed landscapes (70% arable land, 3% pasture, large fields). From June–August 2003 and May–August 2004, butterflies and burnet moths were surveyed 5–6 times/year along 400–750 m routes along cereal field boundaries. Individuals occurring 5 m into the crop and in adjacent 2-m uncultivated margins were counted.

(Summarised by: Andrew Bladon)
Reduce field size (or maintain small fields)

A replicated, site comparison study in 2003–2004 on 24 arable farms in Scania, Sweden (Rundlof & Smith 2006) found that farms with smaller fields in more diverse landscapes had a higher abundance and species richness of butterflies and burnet moths than farms with larger fields in intensively farmed landscapes. Both the abundance (3.6–4.5 individuals/50 m) and species richness (1.4–1.6 species/50 m) of butterflies and burnet moths on farms with small fields in more diverse landscapes were higher than on farms with larger fields (abundance: 0.4–1.7 individuals/50 m; richness: 0.3–0.9 species/50 m). Twelve arable farms with small fields (average: 31,600 m²) in diverse landscapes (15% arable land, 19% pasture), and 12 arable farms with large fields (average: 60,200 m²) in intensively farmed landscapes (70% arable land, 3% pasture) were selected. From June–August 2003 and May–August 2004, butterflies and burnet moths were surveyed 5–6 times/year along 400–750 m routes along cereal field boundaries. Individuals occurring 5 m into the crop and in adjacent 2-m uncultivated margins were counted.

(Summarised by: Andrew Bladon)
Increase the proportion of natural or semi‐natural habitat in the farmed landscape

A replicated, site comparison study in 2003–2004 on 24 arable farms in Scania, Sweden (Rundlof & Smith 2006) found that farms in more diverse landscapes had a higher abundance and species richness of butterflies and burnet moths than farms in intensively farmed landscapes. On farms in diverse landscapes, both the abundance (3.6–4.5 individuals/50 m) and species richness (1.4–1.6 species/50 m) of butterflies and burnet moths were higher than on farms in intensively farmed landscapes (abundance: 0.4–1.7 individuals/50 m; richness: 0.3–0.9 species/50 m). Twelve arable farms in diverse landscapes (15% arable land, 19% pasture, small fields (average: 31,600 m²)), and 12 arable farms in intensively farmed landscapes (70% arable land, 3% pasture, large fields (average: 60,200 m²)) were selected. From June–August 2003 and May–August 2004, butterflies and burnet moths were surveyed 5–6 times/year along 400–750 m routes along cereal field boundaries. Individuals occurring 5 m into the crop and in adjacent 2-m uncultivated margins were counted.

(Summarised by: Andrew Bladon)
Pay farmers to cover the costs of conservation measures (as in agri-environment schemes or conservation incentives)

A replicated, paired, site comparison study in 2003–2004 on 24 arable farms in Scania, Sweden (Rundlof & Smith 2006) found that farms which landowners were paid to manage organically had a higher abundance and species richness of butterflies and burnet moths than conventional farms in intensively farmed but not more diverse landscapes. In intensively farmed landscapes, both the abundance (1.7 individuals/50 m) and species richness (0.9 species/50 m) of butterflies and burnet moths on subsidized organic farms were higher than on conventional farms (abundance: 0.4 individuals/50 m; richness: 0.3 species/50 m). However, in more diverse landscapes, the abundance (4.5 individuals/50 m) and species richness (1.6 species/50 m) of butterflies and burnet moths on subsidized organic farms were not significantly different from conventional farms (abundance: 3.6 individuals/50 m; richness: 1.4 species/50 m). Twelve arable farms with >50% of land under EU-subsidized organic management in 2002 and 12 conventional farms of similar size, crop type and landscape features, were selected. Farm pairs were 3–8 km apart. Six pairs of farms were in diverse landscapes (15% arable land, 19% pasture, small fields), and six pairs were in intensively farmed landscapes (70% arable land, 3% pasture, large fields). From June–August 2003 and May–August 2004, butterflies and burnet moths were surveyed 5–6 times/year along 400–750 m routes along cereal field boundaries. Individuals occurring 5 m into the crop and in adjacent 2-m uncultivated margins were counted.

(Summarised by: Andrew Bladon)