Enhancing floral resources for pollinators in productive agricultural grasslands
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Published source details
Woodcock B.A., Savage J., Bullock J.M., Nowakowski M., Orr R., Tallowin J.R.B. & Pywell R.F. (2014) Enhancing floral resources for pollinators in productive agricultural grasslands. Biological Conservation, 171, 44-51.
Published source details Woodcock B.A., Savage J., Bullock J.M., Nowakowski M., Orr R., Tallowin J.R.B. & Pywell R.F. (2014) Enhancing floral resources for pollinators in productive agricultural grasslands. Biological Conservation, 171, 44-51.
Actions
This study is summarised as evidence for the following.
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Reduce cutting frequency on grassland Action Link |
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Restore arable land to permanent grassland Action Link |
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Reduce grazing intensity on grassland by seasonal removal of livestock Action Link |
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Reduce cutting frequency on grassland
A replicated, randomized, paired, controlled study in 2008–2012 on a farm in Berkshire, UK (Woodcock et al. 2014) found that grasslands established with flowering plants which were cut once/year had a greater abundance and species richness of pollinators (including butterflies) than grasslands cut twice/year. When sown with a seed mix including legumes or legumes and other non-woody, broadleaved plants (forbs), plots cut once/year had a higher abundance (8–91 individuals/plot) and species richness (3–8 species/plot) of pollinators than plots cut twice/year (abundance: 6–52 individuals/plot; richness: 3–6 species/plot). In plots sown with grasses alone, pollinator abundance (0–3 individuals/plot) and species richness (0–2 species/plot) were lower regardless of cutting frequency. In spring 2008, forty-eight 875-m2 plots were sown with one of three seed mixes: a “grass only” mix of five species (30 kg/ha, cost: €83/ha); a “grass and legume” mix of five grasses and seven agricultural legumes (34 kg/ha, €120/ha); or a “grass, legume and forb” mix of five grasses, seven legumes and six non-legume forbs (33.5 kg/ha, €190/ha). Half of the plots were cut to 10 cm once/year in May, and half were cut to 10 cm twice/year in May and August. In May, July and August 2009–2012, butterflies, bees (Apidae) and hoverflies (Syrphidae) were surveyed three times/year on two parallel 20 × 2 m transects/plot.
(Summarised by: Andrew Bladon)
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Restore arable land to permanent grassland
A replicated, randomized, paired, controlled study in 2008–2012 on a farm in Berkshire, UK (Woodcock et al. 2014) found that grasslands established with seed mixes containing legumes and other non-woody, broadleaved plants (forbs) had a higher abundance and species richness of pollinators (including butterflies) than grasslands sown only with grasses. Plots sown with a mix of grasses, legumes and forbs had a higher abundance (9–70 individuals/plot) and species richness (3–7 species/plot) of pollinators over four years than plots sown with grasses only (abundance: 0–3 individuals/plot; richness: 0–2 species/plot). In the first year after establishment, plots sown with grasses and legumes but no forbs had the highest abundance (15–91 individuals/plot) and species richness (5–8 species/plot) of pollinators, but this decreased over time (fourth-year abundance: 3–8 individuals/plot; richness: 2–3 species/plot). Grass and legume plots managed by cutting had a higher abundance (6–91 individuals/plot) and species richness (3–8 species/plot) of pollinators than plots managed by grazing (abundance: 3–33 individuals/plot; richness: 2–5 species/plot). Management had less effect on other seed mixes. In spring 2008, ninety-six 875-m2 plots were sown with one of three seed mixes: a “grass only” mix of five species (30 kg/ha, cost: €83/ha); a “grass and legume” mix of five grasses and seven agricultural legumes (34 kg/ha, €120/ha); or a “grass, legume and forb” mix of five grasses, seven legumes and six non-legume forbs (33.5 kg/ha, €190/ha). Half of the plots were grazed with cattle (3 animals/ha) and half were cut to 10 cm once or twice/year. In May, July and August 2009–2012, butterflies, bees (Apidae) and hoverflies (Syrphidae) were surveyed three times/year on two parallel 20 × 2 m transects/plot.
(Summarised by: Andrew Bladon)
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Reduce grazing intensity on grassland by seasonal removal of livestock
A replicated, randomized, paired, controlled study in 2008–2012 on a farm in Berkshire, UK (Woodcock et al. 2014) found that grasslands established with flowering plants where cattle were removed for part of the summer had a greater abundance and species richness of pollinators (including butterflies) than grasslands grazed throughout summer. When sown with a seed mix including legumes or legumes and other non-woody, broadleaved plants (forbs), plots where cows were removed in the summer had a higher abundance (8–56 individuals/plot) and species richness (3–6 species/plot) than plots where cattle grazed throughout the summer (abundance: 3–49 individuals/plot; richness: 2–7 species/plot). In plots sown with grasses alone, pollinator abundance (0–3 individuals/plot) and species richness (0–2 species/plot) were lower regardless of grazing intensity. In spring 2008, forty-eight 875-m2 plots were sown with one of three seed mixes: a “grass only” mix of five species (30 kg/ha, cost: €83/ha); a “grass and legume” mix of five grasses and seven agricultural legumes (34 kg/ha, €120/ha); or a “grass, legume and forb” mix of five grasses, seven legumes and six non-legume forbs (33.5 kg/ha, €190/ha). Half of the plots were lightly grazed (3 cows/ha, May and September–October) and half were more heavily grazed (3 cows/ha, May–October). In May, July and August 2009–2012, butterflies, bees (Apidae) and hoverflies (Syrphidae) were surveyed three times/year on two parallel 20 × 2 m transects/plot.
(Summarised by: Andrew Bladon)
