Study

Enhancing floral resources for pollinators in productive agricultural grasslands

  • 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.

Action Category

Reduce cutting frequency on grassland

Action Link
Butterfly and Moth Conservation

Restore arable land to permanent grassland

Action Link
Butterfly and Moth Conservation

Reduce grazing intensity on grassland by seasonal removal of livestock

Action Link
Butterfly and Moth Conservation
  1. 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)

  2. 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)

  3. 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)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 19

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust